Please HELP me with 90s - '02 era Dodge B3500/350 Brakes

[98LeisureTravelDodge]

Which Brake Booster do you have in you 3500/350 class B Dodge van (transverse dual diaphragm or fore/aft single diaphragm)?

Which Drum Brake set-up do you have in your 3500/350 class B Dodge van?

What size wheel cylinders (7/8", 1", or...) do you have in your 3500/350 class B Dodge van

Which Rear Axle do you have in your 3500/350 class B Dodge van (Chrysler Corporate HD 9.25 or Dana, or...)?

Who has Dual Rear Wheels in their 3500/350 Dodge class B?

Has anyone gone over to Rear Disc Brakes and can it be done without major mods?

I'm having difficulty diagnosing a long-ish brake pedal in my 1997 based dodge B3500 1 ton Leisure Travel Freedom. After replacing ALL the standard brake components, some multiple times, I still have a long pedal and unimpressive feel.

I am beginning to suspect that someone before me swapped out some non-wear component like the brake pedal or the rear axle with a different configuration than original. I haven't pulled the booster, but it checks good for no vacuum leaks, and supposedly there are no length adjustments on these (it's on my list to check next). My Service Manual says that all the 3500s have the sideways mounted dual-diaphragm booster. I have the front-to-back single diaphragm. I suppose it's possible that the configuration of the vans sold to various coach builders varies from the "norm" - whatever that is?? Or maybe my van got some 1998 model year components - '98 was a major transition year.

My Chrysler Build Sheet says that I have 12" x 3.5" rear drum brakes. As far as I can tell there is no such thing. There are 12 1/8" x 3.5" brakes which I believe is for the duallies. When I got it, it had 12x3" Bendix brakes with a 7/8" bore wheel cylinder on one side and a 1" bore on the other side! I went with 1" and now I'm wondering if 7/8" would make that much differance in pedal height. Would there be a different pedal assembly with a different pedal ratio for all the different configurations?

Any input, insight, or information is greatly appreciated. I have never had this much trouble with brakes and I have owned 3 Gen II D150s. I am beginning to dislike my rv!

btw, I have the corporate 9.25 rear axle.

[98LeisureTravelDodge]

I should add that rear 2whl ABS has been deleted, replacement dump valves are no longer available.

The pedal does not "pump-up".

All 4 wheels lock up on packed sand/clay.

Run out on new Napa drums is within limits.

Rear axle vertical play ~0.011" and 0.008" left/right measured at the flange. The seals don't leak and the bearings are showing some normal? wear. I've thought about changing them, but I hate just throwing parts at it.

In/out end play at the axles is ~0.020" which I believe is typical for the Corporate axles.

[booster]

Not familiar with that model, but do you have an adjustable pushrod from the pedal into the master cylinder? If you do, this is very commonly misadjusted when a replacement master cylinder is put in or existing rebuilt. If you have one, you should be able to find the proper adjustment procedure in a manual or online.

[98LeisureTravelDodge]

I have decided to pull it and take a closer look - the manual says no adjustments, but you never really know until you look, right? I was just up under the dash with a flashlight and came in to compare booster part #s and year models.

My neck hurts already....

[98LeisureTravelDodge]

It also has the 4000# front axle.

[Turbowhiz]

My 1999 has a typical fore-aft brake booster.

According to the Chrysler parts book pdf I found for my 1999 (dated September 15,2005) the brake booster and master cylinder are all the same in the 1999's... (1500/2500/3500).

My van has the Chrysler 9.25 rear end, and 4000lbs front Axel. Rear wheel Antilock.

The part book description of the rear brakes are "Rear Brakes,12 Inches x 3.5 Inches". My part number for the rear brake cylinder is 5010005AA. It seems like its ~1 inch.

Are you sure you have a good bleed of the brakes? Bleed the master cylinder? (the FSM reference I have makes note not to pump the brakes during bleeding!? .. Basically run a hose to a container off the bleeder and let gravity do its thing) ... It also says:

Bleed only one brake component at a time in the following sequence:
-Master Cylinder
-Combination Valve
-Rear Antilock Valve
-Left Rear Wheel
-Right Rear Wheel
-Right Front Wheel
-Left Front Wheel

My brake system is apart at the moment to replace the line between the proportioning valve and the RWAL valve, along with the lines from the master to prop valve as they looking rough due to some battery leakage at some point in my vans life. I'm doing all the rubber hoses too while I'm at it.

Of note, all the flare fittings are metric with ISO bubble flares.

[98LeisureTravelDodge]

Thank you the valuable info. I may respond again, and in more detail when I get home.

Originally Posted by Turbowhiz

My 1999 has a typical fore-aft brake booster.

According to the Chrysler parts book pdf I found for my 1999 (dated September 15,2005) the brake booster and master cylinder are all the same in the 1999's... (1500/2500/3500).

RockAuto concurs with that. It looks like Dodge went to Dual-Diaphragm, Longitudinal-Mount booster/master cylinder for all 1500-3500 in '99. It looks like they transitioned in mid '98, from transverse mount dual-diaphragm to longitudinal mount dual-diaphragm with the 4000# axle.

I'll have to search harder for a parts manual for my 3500.

I'm very interested to see if the 1999 setup will fit under my hood. The dual diaphragms would improve my braking. I'll have to check the yards, but they are all getting crushed even as I write.

The part book description of the rear brakes are "Rear Brakes,12 Inches x 3.5 Inches". My part number for the rear brake cylinder is 5010005AA. It seems like its ~1 inch.

Hmm, I'll dig a little deeper.

Are you sure you have a good bleed of the brakes? Bleed the master cylinder? (the FSM reference I have makes note not to pump the brakes during bleeding!? .. Basically run a hose to a container off the bleeder and let gravity do its thing)

Interesting - I think my manual says to use the container and gently pump. I'll have to read it again. Normally, I would say 110% confident there is no air, but I have read many threads in the Dodge truck forums about people having a difficult time bleeding their brakes. I did bench bleed the master cylinder a number of times and also bleed the closed system in the order listed below. I have gravity bled, Vacuum bled and gently pedal-pump bled. They do not "pump-up" which is the indication of air in the system.

... It also says:

Bleed only one brake component at a time in the following sequence:
-Master Cylinder
-Combination Valve
-Rear Antilock Valve
-Left Rear Wheel
-Right Rear Wheel
-Right Front Wheel
-Left Front Wheel

My brake system is apart at the moment to replace the line between the proportioning valve and the RWAL valve, along with the lines from the master to prop valve as they looking rough due to some battery leakage at some point in my vans life. I'm doing all the rubber hoses too while I'm at it.

I got a RWAL valve off a '99-ish B2500 from a Pull-a-Part. Mine had been removed. I have read many tales of woe re. these dump-valves. I flushed it out by stroking the pedal while energizing each of the solenoids in turn (vial the abs module connector under the glove box). One flushes on the up stroke and the other flushes on the down stroke. A guy who worked at the factory that built the dump-valves wrote on the Dodge Forum that they used a powerful magnet to "energize" the valves because they will burn out if they are energized for more than a few seconds. I was careful to energized only for the time it took to stroke the pedal. I ended up removing it and taking it apart. It was still full of sludge. Another guy in Alaska rebuilt a few of them. He said he had correct o-rings on hand because he worked with hydraulics. I stored it for now and will possibly rebuild it some day. I'll also pull any I come across, but they're not all the same. The chambers have to have enough capacity to match the wheel cylinder size.

Also, a local parts store happened to have a power-booster in stock so I took it home pending further diagnosis (the sales-person said it could be recalled at any time, and that it would be all right for me to make visual comparisons/measurements at home and then return it if need be. I had forgotten that the plunger on mine was unusual (in my experience) in that it has a removable tip. The tip has an ~1" long shaft that slides into a center-drilled hole in the plunger. I had found this over a year ago and determined it was not adjustable. And it isn't adjustable - for me - because I don't have any different length tips. But I only remembered that it wasn't adjustable, and had forgotten about the removable tip until I looked at again yesterday. The new one has the typical threaded adjustment and happens to be adjusted to 0.075" longer than mine. That will probably make a significant difference, but I will be happily surprised if it makes "all the difference". My FSM makes no mention of an adjustment. Does your FSM say anything about adjusting the booster-plunger?

I and also considering checking the flex of my rear brake hose by clamping it off with a brake-hose-clamp and checking the pedal feel. I recall that it is not a 'professional-grade" part and may be sub-par.

Of note, all the flare fittings are metric with ISO bubble flares.

[Turbowhiz]

Here you go:

http://johnmeister.com/jeep/JEEP-TEC..._PDFS/97ab.pdf

No mention of any adjustment at all in the booster in my FSM. Basically is serviced as complete unit, thats it thats all.

I also went to the junk yard, and its about 5 years too late around here I'd say. I was thankfully able to salvage what I wanted (a metal bracket that holds said proportioning valve/rwal valve/rwal computer, along with all said parts although mine were fine) along with a few other minor bits since I was at it, but pickings were slim to say the least, and I had to go a long way to find a yard that had any at all. I was pulling from a 2003, the very end of these vans (and it was the only one they had). At this point my thought is to start collecting parts, especially in my case 98-03 unique parts, as they represent only 6 years vs a lot of stuff thats 78-97 ...

(if I had space to store it I'd just buy a complete running parts van now.. most common parts I doubt will ever be much of an issue, but anything outside of common basic wear parts is getting to be unobtainium even now)

The RWAL valve I pulled appears to be identical from the 2003 as my 1999. The 2003 was a 2500, but it looked to have the same braking system as my 3500, and my 1999 parts manual confirms that, at least in 1999.

I'm putting mine back together with my original parts, as they were in working order. That said I've never had occasion for it to ever kick in. The RWAL system is meant to manage the "unloaded truck" scenario when the back wheels could easily lock under hard braking with no load as the proportioning valve logically is setup for a loaded scenario. In our RV case that isn't a problem, so bypassing it probably isn't the worst idea.

[98LeisureTravelDodge]

Outstanding, Thank you very much. I was comparing '98 & '99 brakes - drums in particular. Didn't find anything yet, but I'm thinking maybe they call them 12" x 3.5" brakes because the friction surface of the drum is 3.5" deep.

I made a tiny shim/washer for the plunger tip out of a piece of landscape edging - it just happened to be .075" thick so that brings it out as far the replacement booster's plunger.

I took it for a test drive and it is much better, but still unsatisfactory. I'll have to take proper measurements and set it at whatever the typical gap is. I'll try to take the measurements off the spare master cylinder and booster if I can satisfy myself they are identical.

Question: Do you use any fancy brake pads like EBC or PowerStop? If yes, how do they perform?

Also, are you a jeep person, too? My daily driver is a 2000 Cherokee 4.0 4wd. That website has a lot of great information.

[booster]

Originally Posted by 98LeisureTravelDodge

Outstanding, Thank you very much. I was comparing '98 & '99 brakes - drums in particular. Didn't find anything yet, but I'm thinking maybe they call them 12" x 3.5" brakes because the friction surface of the drum is 3.5" deep.

I made a tiny shim/washer for the plunger tip out of a piece of landscape edging - it just happened to be .075" thick so that brings it out as far the replacement booster's plunger.

I took it for a test drive and it is much better, but still unsatisfactory. I'll have to take proper measurements and set it at whatever the typical gap is. I'll try to take the measurements off the spare master cylinder and booster if I can satisfy myself they are identical.

Question: Do you use any fancy brake pads like EBC or PowerStop? If yes, how do they perform?

Also, are you a jeep person, too? My daily driver is a 2000 Cherokee 4.0 4wd. That website has a lot of great information.

When you are setting the plunger length, you have to be sure not to go too far so that the master cylinder doesn't compensate, or release the pressure when the pedal comes back up. The easiest way to do it is by having the master cylinder cover off and watching the fluid as someone releases the brake. You should she a small eruption of fluid in the master cylinder as the fluid comes back in to it.


If getting the right length on the rod desn't get you all the way there, you may want to look to see if you are really long on the downtravel of the pedal or is the pedal coming up higher than it is supposed to. I have run in to a couple of peoples vehicles that had that issue and thought the brakes were bad when all they needed was a rubber bumper for the uptravel of the pedal. Rare but happens, and even less with most of the brake switches on the pedals now.


The other thing the might be an issue is master cylinder bleeding which sometimes, again rarely, needs to be done with the "bench procedure" most OEMs recommend but most of us never seem to do. It entails using short brake lines from the outputs of the master back into the reservoir, so there is no chance of backflow and air sucking when trying to bleed them and you can see any air bubbles. Some master cylinders just seem to need it

[vwmaniaman]

I own a 1999 LTV and have had the same issue with my brakes. All the brakes had just been replaced when I purchased it. The pedal was way down when it stopped and I diagnosed it as a bad Master Cylinder. Well, put a new NAPA one in it and now it goes down only half way. It is however much more firm. I have bled mine over and over with the same results. We have taken ours on several trips since then with no issues. I do recommend replacement of those hoses. Had one fail to where the drivers front brake would not release. Had to be towed on that problem.

[booster]

Originally Posted by vwmaniaman

I own a 1999 LTV and have had the same issue with my brakes. All the brakes had just been replaced when I purchased it. The pedal was way down when it stopped and I diagnosed it as a bad Master Cylinder. Well, put a new NAPA one in it and now it goes down only half way. It is however much more firm. I have bled mine over and over with the same results. We have taken ours on several trips since then with no issues. I do recommend replacement of those hoses. Had one fail to where the drivers front brake would not release. Had to be towed on that problem.

I think it is very possible that the master cylinder rebuilders are not paying attention to which pushrod needs to go with the master cylinder or they are using "interchangeable" versions that may have a different depth to the internal plunger and need and different pushrod. We used to run into this all the time with street rods and muscle cars when changing over to disc brakes or from manual to power brakes. Sometimes there were two connection rods to get right as there was one from the pedal to booster and another from the booster to the master cylinder.