Strange Brake Problem or..Sorry for the book.

[HanksB3B]

The right rear wheel slave cylinder leaked and I barely made it home with no brakes.

I examined the cylinder and it appeared that the person in charge of rebuilding the cylinders did a very marginal job and only must have replaced whatever didn’t work at the time.

Since I had replaced the steel lines and rubber hoses I looked into having the master and slave cylinders rebuilt at a shop specializing in that. They told me the cylinders would be examined and sandblasted and re-built like new. $40.00 ea. for the slave cylinders and $60.00 each if they needed to be sleeved.

Since Roberts has been my primary source over the years I called Gary. At $129 for the master and $24.50 (x2) ata the rear wheels and $45 for ea front and that Gary said they are still produced by the original manufacturer for a little over $300 the truck would have a completely new braking system.

I replaced the master the only funny thing with that is that the cover plate had to be rotated 180 deg. so that the filler cap was in the front just like the Truck Manual shows Everything else fit perfectly.

I didn’t do a major adjustment as the pads were new and after the cylinders were in place I just put the drums back on and bled the system. Everything was working fine (no leaks).

I went to the car wash and hosed down the inside of the right rear wheel to wash off all the brake fluid on the inside of the tire.

O.K. heres where the problem begins. The front right wheel would lock-up and skid. At first I had to put the truck into reverse, step on the brake to free it up. I limped it home and found that soft pedal pressure would bring the truck to a stop without locking it up, but step on it too hard and screeeeech!

I looked through the Manual (and wished I had the specialty tool). I found a P-15 D-24 cheat sheet for brake adjustment that someone skillfully put together and studied it as well (see attachment).

The next day I took the right front hub off to get a look. I adjusted the heel pointers so that they pointed toward each other and then did the best I could without the tool I wish I had and just used a caliper type brake tool that measured the drum and the shoes.

I put it back together. The truck exhibited the same problem and so I decided to take it to a very reputable alignment and brake shop that’s been in business for a few family generations. Steve told me that once shoes get soaked with fluids either brake or oil it could cause another one of the brakes to lock-up.

Question-01: Is it possible that because the right rear got wet that it could cause the right front to lock-up ?

Question-02: Does anyone know of someone that has the Ammco or Miller tool and would be willing to either adjust my brakes or let me use it.

Question-03: Any suggestions, opinions and a workplan would be greatly appreciated.

My plan (if the shoe contamination theory is valid) would be to only replace the right rear shoes and somehow manage to do a major adjustment on all four brakes.

Thanks,

Hank

I know somewhere far away from computers along a dusty highway miles away from anything close to Ebay…there’s an old rusty toolbox by the side of the road..I stop and open it up. I looks like an Ammco 1750… no, it looks more like A Miller MT-34-B .

Edited February 4, 2010 by HanksB3B

[MBF]

Hank-contamination on the brake shoe linings will definitely cause them to drag or lock up (grease, brake fluid, etc) and the hotter the shoe gets, the deeper the contaminent works into the shoe. I don't know of any way to removed anything other than suface contamination w/o relining the shoe. I'd also be looking to make sure that the shoe linings are tightly bonded to the metal shoes and not coming apart. Has the right front drum been cut or cleaned? Does it have any surface inperfection or greasy coating that would cause the shoe to grab? Since you replaced the flex lines, were they NOS or newly manufactured? I've seen these collapse internally and cause the shoes to hang up. What type of shape were the return springs in, and did the shoes on both fronts move freely on their anchor pins? Finally, and I'm only guessing here-is there a long shoe and a short shoe on your vehicle? Could you have both longs on the right front instead of one long, and 1 short (sorry I don't remember if these were identical shoes or of differing legnths. I'm sure other folks will be able to offer other suggestions. Good luck. Mike

[oldmopar]

If the right wheel cylinder leaked then that is the problem as Mike explained the fluid that leaked onto the shoe caused the other problems. If this was a new cylinder I would check 1st to be sure there is no damage to the bore and the piston is ok and the correct one if it look ok then get a rebuild kit, new rubbers, just to be safe and reinstall the cylinder

You do need to check all parts before install I just replaced the brakes on my dump truck used all new wheel cylinders and found one of the pistons was frozen so had to exchange it before install. This truck used 2 different size pistons in each cylinder so maybe someone put the wrong one in at the factory. Rockauto replaced the cylinder and even paid for return shipping

[TodFitch]

...snip...

Question-01: Is it possible that because the right rear got wet that it could cause the right front to lock-up ?

No. But you said you replaced the master cylinder. If the push rod is not adjusted correctly so that the relief hole is cleared by the piston when the pedal is up the brakes will lock up and, at least on my old Plymouth, that happens on one wheel slightly before the others (probably a wheel/shoe adjustment issue).

...snip...

Question-02: Does anyone know of someone that has the Ammco or Miller tool and would be willing to either adjust my brakes or let me use it.

They are heavy to ship. I've loaned my Ammco tool out and would do so again but only to someone local to me. Neither your post nor your profile show where you are located so that might limit the number of offers you get.

...snip...

Question-03: Any suggestions, opinions and a workplan would be greatly appreciated.

If your drums are out of round I find that the "by feel" method you attached to your post does a better job than the Ammco tool. And it is possible to get decent, maybe not perfect, but decent brake adjustment that way.

Double check those areas that you worked on prior to the front wheel locking up. I don't see how a change in a rear cylinder could affect a front, but I do see how a change in the master cylinder could affect everything.

[oldmopar]

I need to learn to read when I saw right wc was leaking I was thinking same wheel as lock up problem .

I would also pull the front left as sometimes if the left is not adjusted correctly it will pull to the right.

[desoto1939]

We have also been finding out that the newer brake linings are starting to get glazed quicker and when this happens the the lining get hard and then the brake will have the affect of a wet brake line and the car will pull. I have had this on several occassions.

I now have gone back to the rivetted linings and use the old style brake linings that had the aesbestos.

I have the Ammco tool but require a down payment on it to insure that you return the tool.

Contact me at Desoto1939@aol.com ALso go the Tech Archive and look at the photos of how I did a demo with the tool.

Rich HArtung

Desoto1939@aol.com

[HanksB3B]

Mike Fowler Wrote:

Hank-contamination on the brake shoe linings will definitely cause them to drag or lock up (grease, brake fluid, etc) and the hotter the shoe gets, the deeper the contaminent works into the shoe. I don't know of any way to removed anything other than suface contamination w/o relining the shoe. I'd also be looking to make sure that the shoe linings are tightly bonded to the metal shoes and not coming apart.

They appear to be fine but will double check

Has the right front drum been cut or cleaned? Does it have any surface inperfection or greasy coating that would cause the shoe to grab?

Drums were recently turned within maybe 100 miles of use

Since you replaced the flex lines, were they NOS or newly manufactured? I've seen these collapse internally and cause the shoes to hang up.

Napa supplied the lines but you can’t assume anything so I’ll ask a friend to press on the pedal while I observe.

What type of shape were the return springs in, and did the shoes on both fronts move freely on their anchor pins?

Return springs are all strong and a typical bitch to get on.

Finally, and I'm only guessing here-is there a long shoe and a short shoe on your vehicle? Could you have both longs on the right front instead of one long, and 1 short (sorry I don't remember if these were identical shoes or of differing legnths. I'm sure other folks will be able to offer other suggestions. Good luck. Mike

Long Shoe Short Shoe humm I’ll double check

Old Mopar Wrote:

If the right wheel cylinder leaked then that is the problem as Mike explained the fluid that leaked onto the shoe caused the other problems.

The right rear was the one that leaked but the right front would lock-up

If this was a new cylinder I would check 1st to be sure there is no damage to the bore and the piston is ok and the correct one if it look ok then get a rebuild kit, new rubbers, just to be safe and reinstall the cylinder

I’ll ask a friend to gently depress the pedal while I look to see if there is equal action at the cylinder level

You do need to check all parts before install I just replaced the brakes on my dump truck used all new wheel cylinders and found one of the pistons was frozen so had to exchange it before install.

This truck used 2 different size pistons in each cylinder so maybe someone put the wrong one in at the factory. Rockauto replaced the cylinder and even paid for return shipping.

You don’t mean that there was supposed to be 2 different size pistons do you? Don’t know enough to doubt that but it would seem unusual. I don’t think this is the case on a B3B.

TodFinch Wrote:

Question-01: Is it possible that because the right rear got wet that it could cause the right front to lock-up ?

No. But you said you replaced the master cylinder. If the push rod is not adjusted correctly so that the relief hole is cleared by the piston when the pedal is up the brakes will lock up and, at least on my old Plymouth, that happens on one wheel slightly before the others (probably a wheel/shoe adjustment issue).

I have a feeling you have hit the nail on the head and will make this the first plan of attack (it’s the simpliest)

Question-02: Does anyone know of someone that has the Ammco or Miller tool and would be willing to either adjust my brakes or let me use it.

They are heavy to ship. I've loaned my Ammco tool out and would do so again but only to someone local to me. Neither your post nor your profile show where you are located so that might limit the number of offers you get.

I will fix my profile but I’m in Southern California, Torrance to be exact. 90503 zip.

Question-03: Any suggestions, opinions and a workplan would be greatly appreciated.

If your drums are out of round I find that the "by feel" method you attached to your post does a better job than the Ammco tool. And it is possible to get decent, maybe not perfect, but decent brake adjustment that way.

I’ll go with the by feel method. Should both the heel and toe have equal clearance with the drum?

Double check those areas that you worked on prior to the front wheel locking up. I don't see how a change in a rear cylinder could affect a front, but I do see how a change in the master cylinder could affect everything.

I hope you are right.

Thank you all so much,

Hank

[Merle Coggins]

You don’t mean that there was supposed to be 2 different size pistons do you? Don’t know enough to doubt that but it would seem unusual. I don’t think this is the case on a B3B.

Hank

According to my manuals, the B1B, B2B, & Early B3B used the step bore front wheel cylinders with the 1.25" piston to the front and the 1.375" bore to the rear. After Serial # 82267098 the B3B and B4B use the same cylinder for both sides. I have to assume that it has equal sized pistons if used on both sides.

Merle

[HanksB3B]

You sure know alot. It's time to really dig in and write down my trucks info, the engine # and whatever I can find on the id plate on the door. I sure do appreciate your resourcefulness as I've noticed everyone else here does.

Thanks,

Hank

[HanksB3B]

I'm still not an expert at adjusting the brakes and getting the heal adjustment and toe adjustment just right without the Miller Tool. My brakes aren't locking up, but even though it seems to be stopping well I can still lock up the fronts if I push down really hard. Now, both fronts (rather than one) will skid at the same time. Is it just a matter of a fine tuning with a minor brake adjustment that will ballance out the braking system so that all four wheels get the same amount of stopping power when the pedal is applied? How critical is the pedal free-play adjustment and what are the symptoms of it not being just right? ? I'm not sure I understand the adjustment of the piston in the master cylinder and how it affects the overall braking

Any input would be helpful, Thanks,

Hank

[Dave72dt]

I see Autozone shows 4 different wheeel cylinders for the front of your truck, each for a specific location on the front axle. Is it possible to have them in the incorrect position? Perhaps that is causing your problem.

Brake pedal really doesn't nee much free play. It only needs enough to ensure the piston in the master retracts completely, allowing fluid to return to the chamber. More free play means pushing the pedal further before the brakes start to actuate.

[HanksB3B]

Dave,

Thanks for responding. I looked at having the wheel cylinders rebuilt and they were $40 ea. or $60 ea. if they had to be re-sleeved. Roberts Motor Parts offers the Master at $129, the rears (upper and lower) for $24 ea. and the fronts for $45. The rears can only fit one way for UR, LR, UL, LL. However I guess the double piston fronts could possibly fit on either the right or left side of the vehicle. If in fact they have different pistons sizes they could be on the wrong side. I'll double check with Gary Roberts on Monday. I kind of doubt this is the case but it may be a possibility.

Thanks,

Hank

P.S. Gary tells me that the cylinders are manufactured by the company that originally made them for our trucks back in the day. They installed no problem and seemed like a perfect match. He does know my trucks a B3B.

[Dave72dt]

I rechecked Autozone.com and they apparently have mixed the front cylinders and rear cylinders up. They have only one number listed for what should be a front cyl so I'm guessing it's the same size bore for later serial #. It's possible one of the front cyl has been replaced and you have a step-bore cyl on one side and a same size bore on the other and that will definitely cause uneven braking.

I haven't had any factory brakes apart on mine so was only going by what they were showing.

[Phil Martin]

I had this problem and lining on one shoes was coming loose. Check it close I took it apart three times before I saw this.

[HanksB3B]

was promising! All the theory's Brake Fluid Saturated Linings, Un-bonded linings they are all possibilities, but I think (hope) I got lucky. After replacing all the cylinders and the major heel and toe adjustment everything short of breaking the shoes in a little, getting the truck on a lift and with the wheels on give them a spin and get each one equal to the other. Gosh I hope that works, this is getting tiring (no pun intended). So for the time being, I'm moving on to other things. It has to do with something that happened last Thursday, and again today on my test drive. I think it has to do with fuel pressure, but I'm not sure yet I'll call the thread "Stalling" and can only hope that whoever helps me out will be as helpful as you guys have been.

Thanks to all,

Hank