Topics

Agile slotted brake rotors.


Dennis Herrle
 

Has any one installed the Agile slotted brake rotors on their View/Navion.
I just wonder if they are worth it cost wise and operationally/safety wise?

Dennis, 2011 View K, 65,500 miles, Tucson,AZ.


William Finley
 

Dennis

This made me laugh.. sorry, not trying to make fun.. but I always thought of slotted rotors on race cars like Porsche 911 or BMW M series or Indy Race cars. They stay cooler under extreme brake usage.

Shocked that these are even available.... but hey to each his own.

No.. I don't think these are needed unless you are going to take your rig out on the track for a few laps, or lay on the brakes continuously without downshifting going down a long long grade.

Maybe ESPN could create a new show.. RV  track racing.. with 75 year old drivers spinning out on the curves.

😎

Please note that I am NOT trying to offend you , your post is a valid question.. I'm just trying to be humorous in my reply

Best regards

Bill 06vh



On Sat, Aug 15, 2020 at 2:11 AM Dennis Herrle via groups.io <dennishhherrle=icloud.com@groups.io> wrote:
Has any one installed the Agile slotted brake rotors on their View/Navion.
I just wonder if they are worth it cost wise and operationally/safety wise?

Dennis, 2011 View K, 65,500 miles, Tucson,AZ.




bike_for_life2003
 

Dennis,

Very interesting question.  You will likely get many different opinions so I'll offer ours.

Having driven a lot of very high performance sports cars in my younger years and being a former AF fast jet pilot, I have always been a fan of lots of braking capability. 

When we got our first RV (99 Winnebago Rialta), I was surprised that we had no ABS and also that there was not enough braking capability to lock the wheels.  When we got our 06 View in summer 2017 I found the braking a bit better, especially after we had the rotors and pads changed at the 80K service... Still, I wish I had more braking available if I really needed it.

Braking  effectiveness is governed mainly by rotor size (which we can't control) and pad size (which we can affect but needs bigger calipers).   What slotted/cross-drilled/ventilated rotors give is better cooling which, IMO, is important mainly if doing a lot of mountain driving or if towing something (both of which put more stress on the braking system). 

I had considered the big Brembo calipers and ventilated/cross-drilled rotor package offered by several purveyors but Dr A said they were not necessary for our 06 View (05 Sprinter).   That said, I'm still not satisfied that we do not have enough braking capability to lock up the wheels (I do know how to control a rolling skid which is the most effective braking technique)... ABS would be great, too.

HTH and Happy Trails!

Paul and Christine
06 View 23H in NW FL

 


Dennis Herrle
 

Thanks Bill. No offense taken. Trying to get others’ opinions. Had lots of trouble with rotors warping in an Aerostar years ago and a good grease monkey friend suggested them. With all the weight we carry, I am curious. 

Dennis, 2011 View K 




On Aug 15, 2020, at 5:50 AM, William Finley <wcfinley@...> wrote:


Dennis

This made me laugh.. sorry, not trying to make fun.. but I always thought of slotted rotors on race cars like Porsche 911 or BMW M series or Indy Race cars. They stay cooler under extreme brake usage.

Shocked that these are even available.... but hey to each his own.

No.. I don't think these are needed unless you are going to take your rig out on the track for a few laps, or lay on the brakes continuously without downshifting going down a long long grade.

Maybe ESPN could create a new show.. RV  track racing.. with 75 year old drivers spinning out on the curves.

😎

Please note that I am NOT trying to offend you , your post is a valid question.. I'm just trying to be humorous in my reply

Best regards

Bill 06vh



On Sat, Aug 15, 2020 at 2:11 AM Dennis Herrle via groups.io <dennishhherrle=icloud.com@groups.io> wrote:
Has any one installed the Agile slotted brake rotors on their View/Navion.
I just wonder if they are worth it cost wise and operationally/safety wise?

Dennis, 2011 View K, 65,500 miles, Tucson,AZ.




Dennis Herrle
 




On Aug 15, 2020, at 7:16 AM, bike_for_life2003 <guzowskip@...> wrote:



Dennis,

Very interesting question.  You will likely get many different opinions so I'll offer ours.

Having driven a lot of very high performance sports cars in my younger years and being a former AF fast jet pilot, I have always been a fan of lots of braking capability. 

When we got our first RV (99 Winnebago Rialta), I was surprised that we had no ABS and also that there was not enough braking capability to lock the wheels.  When we got our 06 View in summer 2017 I found the braking a bit better, especially after we had the rotors and pads changed at the 80K service... Still, I wish I had more braking available if I really needed it.

Braking  effectiveness is governed mainly by rotor size (which we can't control) and pad size (which we can affect but needs bigger calipers).   What slotted/cross-drilled/ventilated rotors give is better cooling which, IMO, is important mainly if doing a lot of mountain driving or if towing something (both of which put more stress on the braking system). 

I had considered the big Brembo calipers and ventilated/cross-drilled rotor package offered by several purveyors but Dr A said they were not necessary for our 06 View (05 Sprinter).   That said, I'm still not satisfied that we do not have enough braking capability to lock up the wheels (I do know how to control a rolling skid which is the most effective braking technique)... ABS would be great, too.

HTH and Happy Trails!

Paul and Christine
06 View 23H in NW FL

 


Dennis Herrle
 

Thanks Bill and Christine. I find braking to be more important than acceleration. Appreciate your perspective. Just trying to get some good info. 

Dennis 2011 View K 


On Aug 15, 2020, at 7:16 AM, bike_for_life2003 <guzowskip@...> wrote:



Dennis,

Very interesting question.  You will likely get many different opinions so I'll offer ours.

Having driven a lot of very high performance sports cars in my younger years and being a former AF fast jet pilot, I have always been a fan of lots of braking capability. 

When we got our first RV (99 Winnebago Rialta), I was surprised that we had no ABS and also that there was not enough braking capability to lock the wheels.  When we got our 06 View in summer 2017 I found the braking a bit better, especially after we had the rotors and pads changed at the 80K service... Still, I wish I had more braking available if I really needed it.

Braking  effectiveness is governed mainly by rotor size (which we can't control) and pad size (which we can affect but needs bigger calipers).   What slotted/cross-drilled/ventilated rotors give is better cooling which, IMO, is important mainly if doing a lot of mountain driving or if towing something (both of which put more stress on the braking system). 

I had considered the big Brembo calipers and ventilated/cross-drilled rotor package offered by several purveyors but Dr A said they were not necessary for our 06 View (05 Sprinter).   That said, I'm still not satisfied that we do not have enough braking capability to lock up the wheels (I do know how to control a rolling skid which is the most effective braking technique)... ABS would be great, too.

HTH and Happy Trails!

Paul and Christine
06 View 23H in NW FL

 


Dennis Herrle
 

Sorry, Paul. Nor Bill.  


On Aug 15, 2020, at 10:23 AM, Dennis Herrle via groups.io <dennishhherrle@...> wrote:

Thanks Bill and Christine. I find braking to be more important than acceleration. Appreciate your perspective. Just trying to get some good info. 

Dennis 2011 View K 


On Aug 15, 2020, at 7:16 AM, bike_for_life2003 <guzowskip@...> wrote:



Dennis,

Very interesting question.  You will likely get many different opinions so I'll offer ours.

Having driven a lot of very high performance sports cars in my younger years and being a former AF fast jet pilot, I have always been a fan of lots of braking capability. 

When we got our first RV (99 Winnebago Rialta), I was surprised that we had no ABS and also that there was not enough braking capability to lock the wheels.  When we got our 06 View in summer 2017 I found the braking a bit better, especially after we had the rotors and pads changed at the 80K service... Still, I wish I had more braking available if I really needed it.

Braking  effectiveness is governed mainly by rotor size (which we can't control) and pad size (which we can affect but needs bigger calipers).   What slotted/cross-drilled/ventilated rotors give is better cooling which, IMO, is important mainly if doing a lot of mountain driving or if towing something (both of which put more stress on the braking system). 

I had considered the big Brembo calipers and ventilated/cross-drilled rotor package offered by several purveyors but Dr A said they were not necessary for our 06 View (05 Sprinter).   That said, I'm still not satisfied that we do not have enough braking capability to lock up the wheels (I do know how to control a rolling skid which is the most effective braking technique)... ABS would be great, too.

HTH and Happy Trails!

Paul and Christine
06 View 23H in NW FL

 


old_b4_my_time
 

I tried to do research on this while having the same curiosities as you and I came up with nothing solid regarding the slotted rotors other than also a lot of comparison to race cars, with the standard amount of chuckles and dismissals thrown in.   From a physics perspective, while you gain tiny built-in cooling fans, the surface area of the rotor is diminished, so what is the trade off and gain?   I don't know and I don't follow racing and the needs of it enough to answer this.

Still I must agree with the majority opinion I've seen after years of reading on this topic brought forward from members here and thus I'll have to say I've seen no challenge or shortcoming with this braking system and even while often being quite overloaded.  However, this observation is with one caveat - we are talking only about experiences driving this coach on level ground.   Drive a little in the "real" mountains and you'll quickly discover what limitations this braking system has.   You see the problem is not stopping once or twice but often and in a continuous  series of applications.  I won't go into my own experience as it has been pointed out several times of no interest to anyone, but with that aside, I'm including some tips that may help you if you are concerned with brake performance in the mountains and particularly in areas such as the Canadian Rockies or locations south of the border.   You can certainly get into trouble quickly with this coach on the most challenging slopes, and particularly fully loaded or a little overweight where even those slotted brakes won't do you any good.   The issue with stopping this vehicle or slowing it down is near impossible on long downward runs of extreme slopes because it has no engine braking power, so as with all major trucks and overloaded transport's with their Jake Brakes and multi-speed manual transmissions, and with these facilities their ability to easily traverse any type of terrain, it is proven man cannot live by brakes alone (and that's all we have with this diesel & automatic).     So with this, I'm not sure of your plans but again, if you are considering serious and perhaps remote mountainous country, you need to think twice about doing so in this coach without enhancing it in some manner such as perhaps a 4WD conversion or Telma Retarder, both expensive and extensive modifications.   Of course planned and metered descents can null that out somewhat, so continue reading if you are interested.

Otherwise regarding brake experience, I’ve discovered with a majority of controlled slopes on major highways  on the typical Walmart parking lot outings that most travelers are forced into while accepting today's absence of enough accommodations for all of us, you may not find the experience or sympathy you are looking for when sharing concerns over the braking system.   First clue is that those who claim it adequate have simply not yet been (or may never be) in a situation where they discover brake failure and until they do, their experience will continue to show the braking system to be adequate as it is, with the expected result of their often challenging those who have concerns such as yours.   Truth is, I might even agree with them assuming you're only going to stay on US Interstate highways and never go off on a snaky mountain roadway.  True, there are still a few places in the Rockies that will easily send this baby off a cliff, but that’s fortunately not a constant threat.

In my own experience while dealing with the stock braking system in quite challenging mountainous conditions, below is a formula that has worked for me but also one I'll have to  disclaim credit for if anyone has an accident following it.    First I cannot stress the importance of taking an IR heat detecting gun along on the journey, if not for testing brake rotor temp, but also checking wheel bearing performance, tire tread overheating, etc..

Definition below of "apply a brake sequence" - applying 4 very firm strokes of the brake pedal toward the floor while feeling a notable inertia forward body movement sensation and with the vehicle slowing down at least to a noticeable amount, slightly forcing the body forward and with the pedal held for no more than 5 seconds on each press and after the 4th stroke, then taking the foot completely off the pedal without resting it there.

Here's what I do going down an extreme slope:  If gravity is continuing to increase my speed or RPM to a level of concern and I reach within 5 miles of the speed limit (and I'm in full control at that speed) or once I attain 3500 RPM or greater and everything is still increasing from an increasing gravity drag down the mountain, I apply the first brake sequence to decelerate to 40Mph and then I shift to a lower gear.    If I continue to gain speed and again near the speed limit or the 3500 RPM mark or greater in that lower gear, then I continue to repeat this procedure of applying a brake sequence and down shifting to the next lower gear, noting that the RPM number is what to watch in the lower gear ranges, as the speed limit will no longer be an issue in the lower gear ranges but then the RPM number becomes the main limiting factor (as to not allow the accelerating gravity-pulled decent to send the engine parts flying into the air).   I continue this process until I finally reach 1st gear at which point if I still see gravity continuing to accelerate me to reach above 3500 RPM in 1st gear, then at this point the transmission is failing as a braking option and after about 4-5 "total" brake sequence applications during this particular descent, it's time to then pull over and take a temperature reading of the rotors using the IR gun to see if you are approaching the 450F cool-down point.   

Now you will use your temperature readings and applied brake sequence counts to begin the task of establishing your own allowed maximum number of brake sequences  before next reaching 450F and thus the "pull out and cool down" of the rotors for this particular slope.  While each descent is unique, after a few times going through this, one should eventually become experienced enough to gauge the maximum number of presses allowed simply by counting and feel, however it's never possible to be too cautious other than ensuring your safety while bent down over the tire taking temp readings with any kind of oncoming traffic.   It's likely better to focus on measuring from the passenger side tire due to traffic, while testing both would really be best in case one is maladjusted to take the entire load.   You will be calculating a formula of maximum brake sequences for each encountered grade through various mountainous descents and thus looking for how many brake sequence applications you can apply (without pulling out to cool) before you reach the bottom of each slope. 

Once your calculation indicates it, your nose says it's time from smelling hot brakes or your better intuition tells you it's time to pull over and check the rotor temps, once pulled over and stopped with the vehicle in park and emergency brake on, you either shoot the red beam through the wheel coverings to the rotor surface if you can see the rotor through it or bend down under the front of the cab and shoot the temp of the rotor on the opposite side.  (Note here to always put the vehicle in park and emergency brake on, never have your partner hold the pedal down while you check the temps or you could boil the caliper fluid which can easily happen if you are at a very high temp.)  If the rotor reads e.g. 250F or less, you can continue then with perhaps only 3 more full brake sequences in your "reserve bank" before you need to stop and check the temp again and this will vary according to your vehicle weight and each grade you descend.  

Do note that this is off the top of my head and you will gain experience on your own for each "downward slope of concern".    The key to watch for is at around 450F the rotor surface temp should indicate time to stop and let them cool, as the transfer of heat from the rotor and enough to boil fluid in the calipers can easily occur when the brake is applied for longer durations. If for example the rotors are 450F + and you then stop somewhere and hold the pedal to the floor for any reason, this will often happen.   Reasons that come to mind are e.g.  stopped for a moment at a stop sign after a long run of downhill braking or if you hold on the brake instead of putting the vehicle in park and setting the emergency brake while parked on the side of the road cooling.    Rotors cool from 450F to 180F in about 20 minutes with a nice cool and notable cross-breeze.   Once the rotor cools to around 180F, the cooling is much slower so that is a good launch point to start down the steep slope again with all your counters reset.

Do note that these are very general rules and in general are only needed in the most extreme conditions where one is going down, down, down, down and the rotors don’t have time to cool.  Otherwise the rotors spinning in the air go through uncountable iterations of heating and cooling sequences and they perform flawlessly through all of these.

Also note it's been two years since I last cleaned out my pants after a severe descent so my figures could be a bit off.   The point is, however, that by using this method you can build your own safety formulas.   I've used 450F as my indication for it being time to stop and cool, as this is nearing the boiling point of brake fluid, and I use 180F as a go-again launch point only because  of not wanting to wait too long while pulled over.   Of course life is extremely complicated when there is no shoulder on the road, but I have and would again, set out cones and triangles while cooling my brakes even if it means stopping traffic rather than my putting myself in danger.    But if you do this, at least raise the hood where it doesn't look like you are just resting, as those having working braking systems seldom care to understand your plight, so you might even yell back, it boiled over, I'll be pulling out in 15 minutes so they won't come with torches.

--
Don - 2006 Navion J

--
Don - 2006 Navion J


Glenn Franco
 

Well Don you have the right idea. I have made numerous trips out west to Washington state from Michigan and from Michigan to Florida going through some serious mountain grades with class c, class a motorhomes and just this past month with an Itasca 23H flat towing a Mazda Miata. We crossed the Rockies, Black Hills took the back roads through all and came out the east entrance to Yellowstone, 
The most demanding event is not the downhill but getting that thing up the grade on the back roads. You are right that slotted and drilled rotors do little to improve brake performance especially on an RV.
Down hill I have for years avoided dragging the brakes down hill as that generates brake fade both from overheated linings and boiling brake fluid.
As you mentioned intermittent brake stops are best. I generally do intermittent spike stops to slow the vehicle down not lasting more than seconds to get the vehicle at a lower speed on the down grade. I do this after downshifting to lower gears. You are correct that you don't get engine braking with the diesels but you also don't get it with the gas vehicles for the most part because of the torque converter. Downshifting puts the transmission bands or clutches acting as brakes but their is a limit as to how much they can slow the vehicle down on very steep downgrades.
Using the spike stop procedure I have rarely if ever smelt overheated brakes on my rig.
In my past life I was a Development engineering supervisor for one of the big three. Every summer we would run the grades in Death Valley at full GCVW towing trailers and Baker Grade in California and Nevada. Besides the ascent we had numerous chances to overheat the brakes on the downgrades and we took brake fluid temps on the downgrade. Repeated spike stops with adequate dwell time in between seem to be the best solution for steep downhill braking.
OBTW my last stint was in Truck Brake Engineering and although slotted and drilled rotors may look cool and help to a degree on High Performance Race Vehicles gain is really not worth much on say an RV or HD Truck.
Just my 2 cents worth.
Glenn 2006 23H


Davd Kuhlmann
 

Brakes convert energy to heat. If you create enough heat on long steep down hills two things can happen: the brakes will fade reducing stopping power and or the brake fluid will boil at the wheel cylinders with complete loss on braking until the fluid cools. I have been there entering a turn at 100+ in my Porsche on the track. 

We have driven 240,000 miles combined inon our 07H and our 16j with no brake fade by keeping the load down on long downhills in the Rockies and Sierras. When the motorhomes are empty braking force is improved. Best solution for RVers is to take it easy on downhills, keep weight close to max weight spec and have fun.
Naturally towing adds to the challenge.

By the way i quit boiling brake fluid in the Porsche by changing to hi temp fluid and improving on my rookie technique.  Lap times improve as skills improve and we use the brakes less.
Dave Kuhlmann 16Vj 85k California.


Dennis Herrle
 

Thanks everyone. Fantastic information. 

Dennis 2011 View K 


On Aug 15, 2020, at 2:38 PM, Davd Kuhlmann <davidakuhlmann@...> wrote:


Brakes convert energy to heat. If you create enough heat on long steep down hills two things can happen: the brakes will fade reducing stopping power and or the brake fluid will boil at the wheel cylinders with complete loss on braking until the fluid cools. I have been there entering a turn at 100+ in my Porsche on the track. 

We have driven 240,000 miles combined inon our 07H and our 16j with no brake fade by keeping the load down on long downhills in the Rockies and Sierras. When the motorhomes are empty braking force is improved. Best solution for RVers is to take it easy on downhills, keep weight close to max weight spec and have fun.
Naturally towing adds to the challenge.

By the way i quit boiling brake fluid in the Porsche by changing to hi temp fluid and improving on my rookie technique.  Lap times improve as skills improve and we use the brakes less.
Dave Kuhlmann 16Vj 85k California.


bike_for_life2003
 

Don,

Thanks for the missive.  Good reading while we are locked down.  I'm usually accused of building the atomic clock when someone simply asks the time.  You've taken the trophy from me. Cpngrats.

Paul and Christine
06 View 23H In NW FL


younglr98
 

Ok brake gurus. I just replaced front calipers, pads, rotors with reman Bosch/MB calipers. Bled system and seemed good. Went to local MB and had fluid system flushed. They said “pedal goes further to floor than we are used to, but we bled all air.”
I just did 1400mi round trip to OR/CA border on Pacific Ocean. Drove 97 thru Bend and Umpqua River. (5,000ft climb descend and multiple steep 7 mile sections)
I use the brief spike technique spaced 1/4 mi apart to slow speed 5-8mph, combined with lower gear when needed. “Go down in same gear you climb” I was taught when driving large flatbed.
Braking system is definitely under built and especially if you’re overloaded. Really hazardous out West here.
I was very concerned and massively conservative on this junket. Pedal is definitely going too low when it firms and functions fine, but too close to bottom.
MB felt they had bled it adequately. Does not continue to drop......like master cylinder going bad. Any thoughts????
I plan to do rears this week as they are quite low and E Brake not adequate either.
Don, enjoy your track time! Race braking a WHOLE nother animal than motorhome braking! Lol
I was at Laguna Seca last Sept during MB track time; they wouldn’t let me take the View out for a spin........dang!
Roger 07VJ E WA


Bob
 

Put a dial indicator on each front rotor.
If they are turning out of spec they can open the calipers further than needed causing more pedal travel to close them.

Also make sure no rust or dirt is between the rotor and the hub.
You want the rotor running as true as possible to reduce pedal travel.

Bob 18G

On Aug 16, 2020, at 16:00, younglr98 via groups.io <younglr98=yahoo.com@groups.io> wrote:

Ok brake gurus. I just replaced front calipers, pads, rotors with reman Bosch/MB calipers. Bled system and seemed good. Went to local MB and had fluid system flushed. They said “pedal goes further to floor than we are used to, but we bled all air.”
I just did 1400mi round trip to OR/CA border on Pacific Ocean. Drove 97 thru Bend and Umpqua River. (5,000ft climb descend and multiple steep 7 mile sections)
I use the brief spike technique spaced 1/4 mi apart to slow speed 5-8mph, combined with lower gear when needed. “Go down in same gear you climb” I was taught when driving large flatbed.
Braking system is definitely under built and especially if you’re overloaded. Really hazardous out West here.
I was very concerned and massively conservative on this junket. Pedal is definitely going too low when it firms and functions fine, but too close to bottom.
MB felt they had bled it adequately. Does not continue to drop......like master cylinder going bad. Any thoughts????
I plan to do rears this week as they are quite low and E Brake not adequate either.
Don, enjoy your track time! Race braking a WHOLE nother animal than motorhome braking! Lol
I was at Laguna Seca last Sept during MB track time; they wouldn’t let me take the View out for a spin........dang!
Roger 07VJ E WA



Glenn Franco
 

Hmmmmm?
Well I tend to disagree with the brake system being underbuilt but that's my opinion and you know everyone has one.
The manufacturers test at Gross Combined Vehicle Weight (that's combined with a trailer) for their brake tests. They must pass FMVSS 105 for 2500 and 3500 vehicles. The 1500's must pass FMVss 135 which is the same as passenger car tests.
We just traveled from Florida to Michigan then Michigan to Richland Washington and ran the grades in the Rockies, Black Hills and in and around Yellowstone. No brake issues just what I expect from the vehicle. We were also flat towing a Mazda Miata for ~ 7500 miles. No brake fade, burnt brake lining smell or smoke but I do spike stops at intervals to slow the vehicle down on the steep and severe downgrades.
Moving that much weight down the road it definitely will not stop like a passenger car would at light load. Thats probably what most people can compare it to.

I guess I'm used to trailer towing at GCVW and we have had a 35ft Bounder and 28ft Class C Jayco all of which to be honest performed about the same during downhills as the Navion. And we alway have flat towed the Miata, Jeep CJ, Jeep XJ or used our tow dolly towing PT Cruisers or Neons.

In regards to your low pedal, vehicles with rear drum brakes can demonstrate a low brake pedal if the shoes are out of adjustment. Vehicles like yours have Disc brakes all around and the fluid displaces the pistons as the linings or pads wear. I guess a question that comes to mind is did you replace the brake pads with MB Direct Replacement Semi Met Pads or some after market pads. Pedal feel can be funny if the replacements are not factory replacement.
An example would be Non Asbestos Organic linings or the newer so called Ceramic linings. Also is the Shim or silencer glued or pinned to the back of pad of the same material as the original. Cheap replacements don't even have the silencer shims and these bozos put brake quiet goo all over the backs of the pads, Disgusting.
If your pedal doesn't rise when you pump the pedal slightly ask the dealer if they cycled the ABS pump during the bleed. Other than that its doubtful if its the master cylinder or the booster unless there is a mechanical issue with the linkage like in the pedal sled.

Good Luck
Just my 2 cents worth
Glenn 06 23H


On Sun, Aug 16, 2020 at 4:00 PM younglr98 via groups.io <younglr98=yahoo.com@groups.io> wrote:
Ok brake gurus. I just replaced front calipers, pads, rotors with reman Bosch/MB calipers. Bled system and seemed good. Went to local MB and had fluid system flushed. They said “pedal goes further to floor than we are used to, but we bled all air.”
I just did 1400mi round trip to OR/CA border on Pacific Ocean. Drove 97 thru Bend and Umpqua River. (5,000ft climb descend and multiple steep 7 mile sections)
I use the brief spike technique spaced 1/4 mi apart to slow speed 5-8mph, combined with lower gear when needed. “Go down in same gear you climb” I was taught when driving large flatbed.
Braking system is definitely under built and especially if you’re overloaded.   Really hazardous out West here.
I was very concerned and massively conservative on this junket.  Pedal is definitely going too low when it firms and functions fine, but too close to bottom.
MB felt they had bled it adequately. Does not continue to drop......like master cylinder going bad.     Any thoughts????
I plan to do rears this week as they are quite low and E Brake not adequate either.
Don, enjoy your track time! Race braking a WHOLE nother animal than motorhome braking!  Lol
I was at Laguna Seca last Sept during MB track time; they wouldn’t let me take the View out for a spin........dang!
Roger 07VJ E WA




younglr98
 

Bob,
Thanks. Brand new rotors and measured to spec 21mm if memory correct. I always brass brush and clean hub and add very thin amount of anti seize to hub.
Is it possible the rears are so low caliper pistons overly extended?
Roger 07VJ E WA


Bob
 

I’m not talking thickness. I mount a precision dial indicator .0001 to the strut or spindle and touch it to each side of the mounted rotor without the tire & rim.
Lug nuts installed with washers if need to seat the rotor to the hub. Spin the rotor and check wobble. This is called runout.

Also try to put some twist on the rotor when spinning to check the hub bearings. If the hub spins too easily the bearings and race are worn. It will show on the dial indicator.

Trucks should have around .003 or less.
More than .005 something is wrong.

This link explains runout;


Bob 18G


On Aug 16, 2020, at 18:06, younglr98 via groups.io <younglr98@...> wrote:

Bob,
Thanks. Brand new rotors and measured to spec 21mm if memory correct. I always brass brush and clean hub and add very thin amount of anti seize to hub.
Is it possible the rears are so low caliper pistons overly extended?
Roger 07VJ E WA




Glenn Franco
 

The procedure you are discussing is measuring runout in the brake rotor. Yes you should clean the hub surface and get it free of rust to eliminate it from causing runout. Runout it the rotor does not lead to a low brake pedal unless it is severe and I mean a large amount of runout. In that case it can cause kickback or knock back of the lining which knocks the caliper piston back as well.

What runout results in is DTV (Disc Thickness Variation) which in time causes pedal pulsation when stopping. As the rotor rotates the semi met lining machines away the high and low spot on the rotor and causes this thickness variation. This is mostly noticeable making stops and higher speeds and repeated stops aggravate the issue. With repeated stops the rotor heats up and causes the rotor to potato chip more and the problem seems worse. When they cool down it goes back to the original dimension. This is called Therma DTV.

The uniformed usually say the rotors are warped when in fact they have been machined by the aggressive material in the brake pads and cause pedal pulsation.

New rotors of quality are usually good to 5 microns or less of DTV.

Just my 2 cents worth
Glenn 06 23H


On Sun, Aug 16, 2020 at 9:20 PM Bob via groups.io <nw8r=yahoo.com@groups.io> wrote:
I’m not talking thickness. I mount a precision dial indicator .0001 to the strut or spindle and touch it to each side of the mounted rotor without the tire & rim.
Lug nuts installed with washers if need to seat the rotor to the hub. Spin the rotor and check wobble. This is called runout.

Also try to put some twist on the rotor when spinning to check the hub bearings. If the hub spins too easily the bearings and race are worn. It will show on the dial indicator.

Trucks should have around .003 or less.
More than .005 something is wrong.

This link explains runout;


Bob 18G


On Aug 16, 2020, at 18:06, younglr98 via groups.io <younglr98=yahoo.com@groups.io> wrote:

Bob,
Thanks. Brand new rotors and measured to spec 21mm if memory correct. I always brass brush and clean hub and add very thin amount of anti seize to hub.
Is it possible the rears are so low caliper pistons overly extended?
Roger 07VJ E WA




younglr98
 

Glenn,Bob,Carl,,
Thank you all! My local MB (MB of Spokane )did fluid flush and I
assume they did it correctly. They are a Van USA Sprinter MB dealership and have an outstanding history and reputation in this forum and with others I’ve talked with. I have NO pulsing and when I needed braking on long descents, interval spiking slowed me as expected. Pedal travel just seems lower than previous. I for sure need to offload some things, as with most of us, I’m well below CGWR but probably over GVWR.
Carl, thanks for Dr A test, it should be in my file and I’ll check that out today.
Thank y’all! I have a lot of experience and specific knowledge of the T1N View, esp. house infrastructure, but the professional level of knowledge in this “Brain Trust called a Forum”is Incredible!!! Roger 07VJ E WA


old_b4_my_time
 

On Sun, Aug 16, 2020 at 01:00 PM, younglr98 wrote:
Don, enjoy your track time! Race braking a WHOLE nother animal than motorhome braking! Lol
@Roger you may have me mixed up with the original poster.   I didn't bring up the query about slotted rotors other than confirming my own curiosity as well and my own experience with boiling fluid and losing my brakes down a serious mountain slope. Otherwise I love humor but I never laugh too hard because what is it someone once said "Karma's a bitch" so I therefore try to remain humble when possible.  From one perspective one can look at people who notice issues with the braking system as either insulting the brand with perhaps a sinister motive in mind (a competing marketing rep?), or they simply could have experienced something that brought a concern and they want to resolve it, and that "something" unless one has driven every road and condition on the planet is not anything one person can claim knowledge over unless they have experienced it themselves.   My entering this thread was just to agree with the OP that there are conditions that can cause failure and therefore offered some sympathy and support.  And I did this in part relying on my experience reading here over the years and knowing the type of response anyone who complains about the brakes typically receives.

Still not to belabor the point or get into a banter of "is, isn't, is, isn't a problem", I supplied some numbers and techniques that may help the 99% majority of drivers who may fall into what I call the "white knuckle crowd" and without the background of race-car driving or engineering degrees, they simply want to make it up and down the mountain in one piece and without putting too much stress and wear on their vehicles.   I was trying to illustrate to this to a majority who likely look upon this talk as impossible to understand, giving them a method with a $15 instrument to check the condition of their brakes as they descend a mountain and hopefully as an outcome they will have less stress and diminish the "white knuckle syndrome" with the added benefit of piling up positive feedback to build their own expertise for future down-hill runs.  

Otherwise whether the vehicle can or cannot make it down a mountain safely and with or without issues will depend on the condition of the brake system, the driver, the vehicle load and the slope and no one can ever know how all those combinations of factors can be mixed and the results of all the combinations.   In general if a problem is brought forward, there's normally some type of personal experience to back it up and the best way to see if you are having a problem is look at your temperatures and see if you are on the edge of failure or not.   And it's likely better to check sooner than later going down the mountain.   A quick pull-out and temp check can give you peace of mind and without relying on the outcome or implications of a forum debate.  Evidence of a problem seems always better to rely on than probability of a problem. 
 
--
Don - 2006 Navion J