I have a 64 C10 with a completely stock braking system. I went through the entire braking system, and rebuilt everything, the self adjusters are clean, straight, oiled, and spin freely. The wheel cylinders were all replaced along with the master cylinder, a few hard and soft lines, and anything else that was suspect. I replaced everything with UP or other fairly high quality parts. Pretty standard stuff. Not many miles after the initial replacement of everything the left rear brake started dragging. I found that the wheel cylinder had went, and was locked open. I replaced it with a Wagner unit. I felt a drag on the way home last night, and when I got home I touched all the hubs. Guess which wheel was hot.... left rear feels like it has a hung up brake again, and I'm guessing it's the wheel cylinder. I checked the self adjuster thoroughly after the last time, it's functioning well. It is the last wheel cylinder in line. I'm wondering if that has anything to do with it giving up. Any ideas or suggestions?
Could be worn backing plates and the shoes are hanging up on the nubs. Also had a Granada with a kinked parking brake cable that for some reason caused the brake to drag eventually even though it was never used. Worked fine once straightened back out.
It's the end of the line on the rear circuit with the GM early 60s fruit jar. I replaced the hard steel line when I initially did all the brakes. Bled them out after the first wheel cylinder went and was getting good solid flow out the bleeder. As for checking them now, I'm not quite quick enough to push the pedal and then go check. I know everyone is going to jump on me about replacing that fruit jar, but, I don't need to hear that, it's working fine, and I'm pretty good about keeping an eye on things. The wheel cylinder is what is going out. I'm wondering if it being the "end of the line" is part of the problem...
This would be the backing plate in question. Didn't notice any real bad grooves worn in, but, I'll check that when I get the wheel off. Thanks for the ideas. Gives me more stuff to check. Just found it odd that it's been the same wheel two times within 3000 miles.
Answer this for us then. You can clearly see that the shoes are not getting seated back onto the anchor pin? 2) things then if thats what you see. 1) has been said already, shoe is hanging up on back plate, or 2) weak return spring and shoe or shoes are getting wedged against the drum. Other possibility, self adjust problem
Check the parking brake cable. The cables on my Bronco2 rusted up. When backing up the cable is pulled & won't retract, making the shoe drag when you go forward.
Last time it was that the cylinder had locked partially open and was seeping fluid. It took some work, once off, to be able to shove it back closed. I do see a bit of a groove on the upper right resting spot in the picture. I'll head home and check that out. Thanks for the ideas guys.
I missed the part about wheel cly being opened. The brake cable hang up is something that I never thought of, but makes real good sense. It would make the shoe stay away from the anchor pin. Not my brake problem, but yet I learned something today
Also, I did replace all of the springs when I did the brakes, but, the springs in those kits aren' t the best these days.
The park cables would be the next thing to check out. With the brakes adjusted for about .030" shoe-to-drum, the park struts should have some clearance. Install the drums, apply and release the park brake, pull the drums and make sure the shoes are seated against their anchors and the struts are not loaded.
Check that you have sufficent play between the Master Cylinder piston and the pushrod, It should be about 1/8" to allow the piston to retract, and relieve Hydraulic pressure on the entire brake system.
I know it may be the picture; but like the other guys noted, it sure looks like there are grooves on the shoe rests to me, too. Weld them up and grind them smooth.
You said the brake cylinder was stuck open and seeping fluid. I can't imagine that happening unless the cylinder opened much further than normal...which suggests that the brakes were adjusted too loosely, the drums have been turned far beyond the recommended limit, or the shoes are loose and/or binding and being forced so far out of postition, as to allow the pistons to at least partially exit the cylinder. Or possibly the rubber cups weren't in correct position and caused the hang-up. Were the pins that hold the shoes to the backing plate still present? Are all the correct springs present and inserted into the correct holes...the exact same as the other brakes? The only other thing I can think of, would be the unlikely case that a piece of depris is in the cylinder, allowing fluid to enter, but not exit the cylinder.
If the adjusters are being loosened instead of tightened, that would allow the cylinders to eventually have to open too far, get stuck, and bind the brakes.
Dude, Judy should finally be up and moving around tomorrow, so if you would like to come over and use the welder your more than welcome.
Could be a combination of problems. Shoes on correctly? (short one in front long one in back)etc. Back rubber line new? (I have seen old rubber lines collapse inside letting pressure go to the wheel cylinder but not letting it release back to the master when you let off the brake making the line hold pressure constantly to anything past it) *looks like the other side would do it as well but there may be something else causing the leaking side to be the weaker link What kind of master cylinder did you change to? single resevoir? Brakes adjusted with wheel on, rolling, to check for snug brake adjustment?
The self ajustors one is left and right thread. check out. Next with shoes on pistons in,measure drum and bring shoes out 1/8 less then drum 3 and 9 oclock. Now if you can,t get drum on. They are most likely to long on top. You can chamfer all FOUR ends across 1/8 depth and back 1/2" Grind them to get drum on.Make sure braks on long and short to.
I don't see where you said you changed the rear brake hose. In theory if it's bad it should be putting pressure into both rear brakes, but maybe there's a bit of air in the other side.
Odd that the wheel cylinder had come out far enough to leak, that means the piston the brake shoe rides on would have had to fall out of the cylinder for the rubber cup to get far enough out to leak, if this is what truly happened the wrong shoes,cylinder would have had to been incorrect for this pickup, plus the drum would have had to have been turned pretty big also. Did you have the shoes arched or checked to see that they fit the drum nicely, ios the drum still close to within specs as far as outer diamiter,the levbers for the auto adjusters are for right and left sides so I don't think those could be swapped around, there is a possibility for swapping the adjuster side to side but I haven't bothered to check that myself. If the other side is working correctly pull the drum off of it and see if there is a difference in the way you set up the malfunctioning side, it almost sound slike the adjuster is backing off and or you didn't set the intital adj snug enough to start with.
Where is the brake hose "T" block located, on the side with the wheel cylinder problem? I would replace the hose regardless. The grooves on the backing plate don't look that bad to hang up the shoes, unless the drum was a real mofo to get off. I like the idea of the brake cable hanging up, a dirty job but I'd take it apart to see if the cable has a kink in it somewhere. The equalizer bar that goes between the shoes should not be tight, it should have some movement to it. Last, swap as many parts from one side to the other just to see what happens. Bob
the self adjuster on that wheel is the wrong thread, moveing the piston out till it binds up in the cylinder as it adjustes
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