MNorby

My buddy's 98 Cummins 2500 front brakes are sticking. Once they are cool you can drive for a bit then they get hotter and hotter to the point you almost can't move. Kinda thinking it is the master cylinder and it is presurrizing up the back side of the plunger and making the calipers not be able to retract basically. Does this sound kosher or anyone else seen this or have any ideas? If so would a MC off something like a V10 rig or anything else fit it if we can find one in a salvage yard? Need something cheap and quick basically. Not sure if the gassers have hydro-boost either. Any help is appreciated, thanks.

P.J

How do the calipers themselves look? I have an 89 International Box truck that had craked boots around the pistons. Pistons rust, then extend but have trouble retracting. New caliper, no more smoke&heat.
This is Both sides at the same time?
?

infidel

Besides sticking calipers a bad hose can cause the brakes to stick.
What can happen is that the inner ply of the hose can separate and make a flap that stops the backflow to the master. Hard to tell if this is the problem by just looking, you have to throw parts at it hoping it is the problem.

Also remove the caliper pins and lube them up with high temp brake grease. If you remove and replace the pins one at a time you don't need to remove the tire or even jack the truck up.

Worn out front wheel bearings will also cause the pads to rub and heat up.

MNorby

It happened to both front wheels at the same time so that makes me want to rule out caliper problems and more of a central braking issue such as MC.

John Faughn

sounds like the res. is too full and as the fluid heats up it expands against the cal. did the pads just get changed and not dain the excess fluid ? also check to see if the calipers move freely by hand .

MNorby

nothing changed in the brake system. Happened when coming home off a dirt road and starting down the mountain. At first they suspected mud and such in the calapers so they stopped at a place and washed out the front brakes and all and still had the prob. Wouldn't make sense about being too full since it hasn't been messed with or changed/ added to for as long as I can ever remember from when he bought it and from when my other buddy had it before he sold it to him

j-fox

Here is what I've found. Pull the inboard pad--piston side - and measure it for thickness. The trailing edge and leading edes will be different. SHOULD be the same.
The pads wear at a taper and this allows the piston to **** over and then it can't retract.
Either replace them or swap left to right!!!

Haulin_in_Dixie

the calipers probably need rebuilding, simple job, clean out the groove and put a new seal in it, replace the pistons if they are damaged. Make sure the pedal is coming back far enough to clear the master cylinder. Or the master cylinder can be plugged in the relief hole.

MNorby

Sound slike pretty easy to rebuild the calapers I take it. I ordered a rebuild kit for both and start there since it is cheapest option and probably wouldn't hurt to do anyways. Anyone have steps or advise about doing it? Thanks

Haulin_in_Dixie

Watch the groove that the seal sets in, it can have rust buildup in the bottom, which causes sticking. You might have to make a little tool to scrape it out, use a small file ground with a scraper on the end. Also if the pistions are not perfect replace them or if you can't get them, replace the caliper.

MARKY MARK

This happened to me about a year ago. My brakes were fine for the first 10 minutes but then it felt like I was pulling a trailer or something. I could smell the hot brakes and the front wheels were very hot to the touch. Took it to the dealer and they said the hydro booster needed to be replaced. Had it done. No problems after that. Not sure if this helps.

Mark

wings

I just talked to a long time friend and hotrodder who owns a real auto parts store. Where you get real parts not Pacific rim stuff.
Infidel hit right on the nose. The guy at the auto parts store said he had just fixed 2 trucks with the collapsed hose problem. One had both fronts collapsed. He said they had a tough time finding the problem untill they tried bleeding the brakes on the first one. When they first opened the bleeder fluid shot out all over. Each time they pumped the brakes the same thing happened. Finally it clicked and they took off the hoses and ...violia the inner walls had peeled away. What happened was the pressure applied the brakes but could not return because the inner hose made like a check valve in the line.

Hopfully it is this and not you hydroboost. $$$ good luck.

I had the same thing happen several time on double wall exhaust pipes . Car would run around town but choke up on the highway.

bentwings