Ebrake Issues (I hope...)

[sggoat]

Sure seems like a brake issue to me. Doesn't appear to be related to the seal, either; I would vote wheel cylinder sticking. Had one stuck on my 77 on the right front--pulled hard and heated the wheel/hub---check the temp of the whee/ hub after driving a SHORT ways--the brake sticking will heat it up way faster than a bad seal/bearing

 

[jmdaniel]

Sure seems like a brake issue to me. Doesn't appear to be related to the seal, either; I would vote wheel cylinder sticking. Had one stuck on my 77 on the right front--pulled hard and heated the wheel/hub---check the temp of the whee/ hub after driving a SHORT ways--the brake sticking will heat it up way faster than a bad seal/bearing

It was hot, I know that. I'm just worried the heat ruined the seal. I wonder if some excess brake cleaner would have damaged one or both of the wheel cylinders. They are both very new, seems too new to be sticking.

 

[coleman2347]

JM, Just read through this, have to agree with wheel cylinders, I would not let the fact that both are very new influence your decision. I have seen many times "new parts" fail. The heat could have indeed warped the seal. I would pull the drum and have a friend work the brakes and look for signs of sticking. Or even do the same with the rear end jacked up and in gear engine running. Of course with all the applicable safety things in place (chocks, jack stands etc). If nothing else this will give you a place to start.

 

[jmdaniel]

All right, thanks all for the great advice. We have some folks coming in for the weekend, so I won't be able to get into it this week, but when I do, I'll report back.

 

[lefty b]

I would vote wheel cylinder sticking. Had one stuck on my 77 on the right front

Not trying to get into semantics, but the front of a '77 has disk brakes, and calipers. And yeah, they are capable of sticking, just had to replace mine for that very reason, but the diagnosis of drum brakes sticking is different because of all the moving parts.

<<<<< EDIT: See post #29 below about why the above 3 lines aren't accurate. Mea culpa. >>>>>>>>>>>

JM, looking through the pictures in the post, I see that the backing plates show the telltale sheen of the oil from the leaks, as do the metal parts of the pads. Not knowing what color the linings were to begin with, even though it's a pain in the butt, I might pull the drum off the other side to get a real world comparison. I'd also feel the ones that have been wet. Even though they might appear to be dry, especially after getting hot, most of the time they have kind of a slimy feel to them, as opposed to the dry, almost fibrous feel of new friction material. Also, I would caution you about pushing the brake pedal without the drum in place. Hydraulics are not unlike electricity with the "path of least resistance" rule. With the line pressure being equal to all 4 cups (2 per cylinder), and mechanical resistance NOT guaranteed to be equal, the odds of all 4 moving simultaneously is quite low. The drum limits the travel of the mechanics, and by doing so equalizes the pressure throughout the brake circuit. More than likely, with all the fluid going to the one cup out of the 8 in the rear brakes that can move the easiest, you'll end up just popping it out and not diagnosing anything. Since it looks like you are changing shoes anyway, with the shoes off you could try manually moving the cups in the cylinders. My gut feeling is that they are fine, but moving them ever so slightly will verify that they are free to move in their bores. I would also thoroughly clean the backing plates, springs, etc with brake cleaner before reassembly. That will give you a good baseline if problems do arise, since anything new will have happened since the last time you were in there.
The rears on my '76 are going to get some much needed attention before the end of the year, I'll be glad if they look as good as yours (even with the problems) when I'm done.

lefty b

BTW: Us Seahawks fans know a thing or two about disappointment. Maybe not at the moment, but it can always rear it's ugly head.

 

[jmdaniel]

All good, lefty b. My plan is to get a new set of shoes, and a couple of rebuild kits for the cylinders, before I tear it all apart. The shoes have to be hosed, because I knew what they looked like brand new, and it wasn't that. I just can't figure what would cause them to lock up, I would think greasy shoes would simply cause longer stopping distance, not lock the wheel up. I have a paper towel between the rim and the bottom of the brake drum, to see if I get any further gear oil leakage. I had none, after the seal replacement, and before the smoky wheel incident, so I'm crossing my fingers that the seal didn't get damaged by the heat.

 

[Leaping Deer]

Not trying to get into semantics, but the front of a '77 has disk brakes, and calipers. And yeah, they are capable of sticking, just had to replace mine for that very reason, but the diagnosis of drum brakes sticking is different because of all the moving parts

FYI not all 40s switched to disk brakes in 76. I know of a few markets which didn't. My 77 45 came from AU and had front drums. Its possible the guy has a truck which was imported to the US. There are quite a few of those kicking around these days.

 

[lefty b]

FYI not all 40s switched to disk brakes in 76. I know of a few markets which didn't. My 77 45 came from AU and had front drums.

Well I'll be dipped. Looked around, and sure enough found this on SOR's "Brake Shoe" page:

"These are USA Specifcations. Some parts of the world had front drum brakes as
late as May 1982."

I bet you could have taken a poll out here and come up with post-'75 as the drop dead date for front drums about 95% of the time. Seem as though my feeble little US Spec brain wheeled out the big, WIDE, brush and started painting . So, my apologies for spreading dis-information. I feel I should probably edit my earlier post to reflect it's inaccuracies, as well as my shortsightedness, so that's the plan.

Hopefully there wont be any more groundbreaking revelations coming out that show soaking brake shoes in gear oil helps improve their performance. I just won't be able to take it. :rimshot


lefty (the "now gonna' be careful about spreading gross generalizations") b

 

[subzali]

I would try backing off the adjustment on the cylinders and go for another drive and see if that helps. Maybe you just had them too tight? I know, that sounds dumb but I'm puzzled about this one since it is only affecting one side and on a '77 the e-brake is on the t-case.

I bet your seal is toast though.

Can you pull the drum off without backing off on the cylinders? Has your drum been machined round lately?

 

[jmdaniel]

Well I'll be dipped. Looked around, and sure enough found this on SOR's "Brake Shoe" page:

"These are USA Specifcations. Some parts of the world had front drum brakes as
late as May 1982."

I bet you could have taken a poll out here and come up with post-'75 as the drop dead date for front drums about 95% of the time. Seem as though my feeble little US Spec brain wheeled out the big, WIDE, brush and started painting . So, my apologies for spreading dis-information. I feel I should probably edit my earlier post to reflect it's inaccuracies, as well as my shortsightedness, so that's the plan.

Hopefully there wont be any more groundbreaking revelations coming out that show soaking brake shoes in gear oil helps improve their performance. I just won't be able to take it. :rimshot


lefty (the "now gonna' be careful about spreading gross generalizations") b

Don't beat yourself up, lefty b. The very first sentence in my first post was:

The saga continues with my driver's side rear wheel.

The potential of the front being stock drums has now been established at least as a possibility; the rear? Never...

 

[jmdaniel]

I would try backing off the adjustment on the cylinders and go for another drive and see if that helps. Maybe you just had them too tight? I know, that sounds dumb but I'm puzzled about this one since it is only affecting one side and on a '77 the e-brake is on the t-case.

I bet your seal is toast though.

Can you pull the drum off without backing off on the cylinders? Has your drum been machined round lately?

I know I didn't have them too tight, as I could still turn them. And I drove it for about 5-6 miles immediately after the seal replace, with no issue.

It will be a week or so until I can take a peek at it, have company coming in for a long weekend. I did order new shoes today, and a brake rebuild kit. The latter was only $15, and it is a possibility that I broke a spring, which would leave the shoes against the drum, right?

I did a search on shoes swelling with gear oil on them, and I guess it's not that uncommon:

http://www.toyota-4runner.org/3rd-gen-t4rs/130916-brakes-sticking-my-toyota-4runner.html

http://www.fullsizebronco.com/forum/archive/index.php/t-64448.html

I'm guessing that's my issue. Hopefully, it's just the shoes, and my seal is still good. That's an easy fix.

 

[lefty b]

Don't beat yourself up, lefty b.

No worries. I'm absolutely confident in my knowledge, and honestly, wouldn't offer it up if I didn't think it was valuable. I just wanted to make it clear that I was amiable, and to poke a little fun at how serious people get about what they THINK they know. My goal is to learn new things every day, and to somehow pass along most of it. When I was in high school, we still had the arching machine for brake shoes, and learned the ropes from a man who had been doing it since the late 50s. I haven't been wrenching for a living for a while, but it is still firmly stuck in my mind.

lefty b

 

[subzali]

I know I didn't have them too tight, as I could still turn them. And I drove it for about 5-6 miles immediately after the seal replace, with no issue.

It will be a week or so until I can take a peek at it, have company coming in for a long weekend. I did order new shoes today, and a brake rebuild kit. The latter was only $15, and it is a possibility that I broke a spring, which would leave the shoes against the drum, right?

I did a search on shoes swelling with gear oil on them, and I guess it's not that uncommon:

http://www.toyota-4runner.org/3rd-gen-t4rs/130916-brakes-sticking-my-toyota-4runner.html

http://www.fullsizebronco.com/forum/archive/index.php/t-64448.html

I'm guessing that's my issue. Hopefully, it's just the shoes, and my seal is still good. That's an easy fix.

I am glad you shared this because I have had sticking brakes on my Tundra for some time and thought it was the e-brake bellcranks. After crawling under there last night and seeing some dried oil fuzz on my back plate, I'm pretty sure it's a leaking seal that is causing my shoes to swell.

 

[jmdaniel]

One of the great things about MUD is all the help provided; another is realizing that we're not alone in our conundrums!

 

[jmdaniel]

Well, I changed the seal and put in some new brake shoes last weekend, and drove it about 40 miles yesterday. Everything seemed fine, but this morning I was going to back it out of the garage, and noticed gear oil on the driver's side rear tire again! I've put three seals in now, and this one had the shortest life span, at one week. I'm going to do it one more time; this time replacing the wheel bearing as well, and if that doesn't do the trick, it will be time to look around for a new axle.

 

[saryon7]

I wish I got to you sooner, cause I wanted you to try a test. I was thinking about a few things:

Probably not the parking brake since that would affect both wheels.

Oil or grease on the shoes definitely causes wheel lock up, but I haven't heard of it keeping the shoes locked even after the brakes are released.

You hypothesis about the swelling brake shoes seems like a great idea. Georg passed on a tip to me of dipping your shoes in lacquer thinner for about an hour, then taking them out and spraying them down with brake cleaner. Repeat this until the shoes are clean. It worked great for my parking brake shoes. Not sure I would do it for my normal brake shoes though.

An easy test to check your cylinders for sticking is to pull off just the suspect drum and leave all other brakes in their normal working conditions. Then SLOWLY press the brake pedal and watch the shoes' movement. Watch to check if the wheel cylinders are binding up at all. Be sure to press slowly because all the pressure will go to this one wheel and if you press the pedal too much you will push the pistons out of the wheel cylinders.

A common problem for a brake to lock up like you describe is a pinched brake line. When you press the pedal it puts out tremendous pressure, which easily goes past the restriction, but the brake fluid can't easily get back out so the tire stays locked.

Seems likely that your seals are failing because of the heat.

Any chance your wheel bearing is bad? Maybe when you turn the wheel on jack stands, it spins freely but when the weight of the vehicle comes into play the shoes are forced into the bottom of the drum. Is the wear even on the shoes?

just some thoughts,
john