my buddies truck has this same problem well except without the lock up just have to push the pedel further and further and it never feels like its going to stop the only time it stops good is when we have a trailer with brake axles on it lol has anyone tried replacing/rebuilding the master cylinder? also if it is the vacume pump can it be rebuilt or just replaced?

 

With either the GM cylinders or the OEM cylinders mine will lock up if they are damp and out of adjustment. If I keep them adjusted they will not lock when they are damp.

 

Clayten, I've tried adjusting them. Actually, I even had my brother-in-law adjust them once thinking maybe I wasn't adjusting them correctly. I get the same result reguardless of adjustment. Moisture does make it worse, but, it burns off by the time I get to the end of my street and it's back to the usual problem.

rebel5422, I was wondering about the master cylinder. I thought I heard once that a master cylinder can cause this type of problem without the usual sinking pedal indicator, but, I don't really know if that's true. I believe it has to do with the little "cup" that seals inside the master cylinder. When you push hard on the pedal it seals better than if you are feathering the brake since the back pressure from the brake fluid helps it seal. I'm wondering if I'm picking up on a master cylinder that's slowly going. The only other reason I suspect the master cylinder is the culpret is when the last brake line blew, which fed the rears btw, the pedal went straight to the floor. Like a an idiot, instead of pushing in the emergency brake, I pumped the pedal at least 10 times before I got any indication of stopping ability. I probably pushed the plunger in the master cylinder way past it's normal position into a corroded portion of the bore. Also, like a bigger idiot, I drove it home like that. As fast as I could push the pedal down, it would pump fluid out. There was literally no resistance for the first 8-10 pumps and no signs of stopping ability. Fortunately, I only had to stop 3 times after the line blew.

 

i asked my brother and he sugested brake master cylinder he said that it was "bleeding down" after the initial press of the pedel but i have not replaced ($) and cant find rebuild kit but strangely all day today the abs light was not on and the truck seemed to stop better and i also have a slight reason to beleive my vacume pump is failing cause at low idle it is hard to steer and today while the light was off everything was ok maybe i have a bad master and vacume it was just a suggestion to look to something a little more simple

 

There is a milder version of the GM wheel cylinders that is 1 1/16 inch bore. Slightly larger than OEM Dodge.
As everyone knows rear brake adjustment is critical. In addition the brand of shoe used can have a large effect on lockup. Unfortunatelly I have no recomendation on a improved lining. I have chamfered the leading edge of shoes with limited success. Sometimes just cleaning the lining with sandpaper helps.

 

Steering has nothing to do with vacuum, it's hydro assisted.
Sounds to me your problem is simple, idle is too low. Can't really trust the dash gauge, go by ear.
Adjustment instructions http://dodgeram.org/tech/dsl/adjustm...d_Gen-Idle.htm

 

we adjusted idel by ear still same thing and weve had to change the steering box twice just going to change ps pump and all vacume lines

 

Well I'll just say I got done doing a full rear brake rebuild including doing these wheel cylinders and I am very pleased. At first I was concerned it would take little pedal effort to lock up the rears after reading some of this post, but it takes a good bit to lock them up.

Much better feel. I did have to tweak the hard brake lines a touch to get them on though. No issues still.

 

I replaced my rear shoes and wheel cylinders on my 96 2500 last weekend, they were getting thin and the wheel cylinders had damp dust around the boot edges.
I upgraded to 27mm Dodge wheel cylinders and Porterfield R4-S carbon-kevlar shoes. VERY GOOD IMPROVEMENT!!!!!!!!! Good initial bite hot or cold.
The price of the shoes was reasonable (not cheap, reasonable) , they did have to special order them so It was about 2 weeks to get them.
The Porterfield R4-S compound appears ot be very highly thought of with several of my friends that road race SCCA events at a competive level. I have been using EBC pads (green & red) on the front of other vehicles.
The truck is gonna get R4-S or EBC Yellow front pads when funds allow.
Upgraded friction material makes a big difference, except when your upside down

 

Just make sure the pad material isn't so hard that it eats your rotors.
Much easier (and cheaper) to replace pads than rotors.

 

Porterfield claims the R4-S compound is very rotor/drum friendly, Scott at work has been running the same rotors 7-8 years just changing pads when needed, It's his weekend/ race car, he drives it like he stole it.
These will most likely be next front pads, and they are $50 cheaper the EBC YELLOW

EBC YELLOW pads claim to be rotor friendly. (no personal experience with these.)
The EBC 2000 GREEN STUFF pads on my 96 Jeep XJ "eat rotors like a german car." My wife is hard on brakes so it is easier on me to put rotors on the Jeep when changing pads than to machine the rotors 2 or 3 times between pad changes. The first pair of green pads trued the old rotors in 2 weeks, by 5k large lip on rotors. I wouldn't put these on anything with hard to change or expensive rotors.
Dodge 2500 4x4 makes easy on rotor pads a very high priority.

 

Had my original 24mm wheel clyinder go out last week so I put the 37337 new cyliners on along with some shoes from advance. Couldnt be happier with the brakes on my truck it will actually stop now. The pedal is alot firmer now and it feels like I got plenty of more avalible stoping power.

Napa said that 4737337 was no longer availble but that 37337 was the same.

 

I did the larger cylinder upgrade in summer and I have recently been having the exact same problems you are having. Have you found the solution? I hate the way my trucks brakes are working.

 

Guys I have been keeping up with this thread also. I have A 96 3500 dually that I pull my 37ft 5th wheel with. It has only had one set of new back shoes since new with 128000 on it. It never has stopped real good with A load. I have put on 4 sets of front pads and it will cleat the front tires from trying to stop with A load. This is the first time I have heard of this. For the money I am going to try it in the next few weeks sure hope it helps and dont cause it to lock up when stopping. thanks very much for the info

 

It is hydro assisted, no question here, so I'd think that hard steering may indicate that the steering pump is not developing enough pressure for either steering and / or braking.