new shoes--new problems!?

[xray]

Hey folks,

Just got done redoing the rear brakes on my 1972, and the shoes on the driver's side bind on the drum. The binding is not so bad that the wheel won't turn, it just doesn't spin more than 1/3 revolution (passenger side will spin 2 times by comparison. Struts are not mounted yet, and new rear wheel cylinder adjusting wheel is fully screwed in on both sides.

Am I missing something? Will this issues be resolved by e-brake adjustment, rear wheel adjusting/proportion valves, etc?

Any thoughts are appreciated...

Here is a pic:

Thanks,

Steve

[montoya_fan01]

Hey folks,

Just got done redoing the rear brakes on my 1972, and the shoes on the driver's side bind on the drum. The binding is not so bad that the wheel won't turn, it just doesn't spin more than 1/3 revolution (passenger side will spin 2 times by comparison. Struts are not mounted yet, and new rear wheel cylinder adjusting wheel is fully screwed in on both sides.

Am I missing something? Will this issues be resolved by e-brake adjustment, rear wheel adjusting/proportion valves, etc?

Any thoughts are appreciated...

Here is a pic:

Thanks,

Steve

Sounds like the wheel cylinder might not be centered in the slot of the backing plate.

If the shoes bind on the drum now, and if the adjuster is already screwed in all the way, adjusting the e-brake (which at this point could only "screw out" the adjuster) isn't going to help, it will make things worse.

Proportion valve won't have anything to do with it.

I'm not sure what you mean by "rear wheel adjusting".

Are you sure that you have the shoes on right?

[mriz]

I'm not sure on the older Z's but check your springs.By the pic it looks like one side is behind/posterior to the shoe and the other side anterior for the top spring.The bottom one looks to be behind/posterior on both sides. I'm working on my 77 brakes now and both upper/lower springs sit on the anterior surface of the shoe. I'm not even sure if it matters but worth looking at.

[xray]

Thanks for the tips...The springs are well-engaged and were put back on the way I found them on disassembly (wheels spun fine with minimal engagement). I think the cylinders are on straight, but honestly not that sure. Because the other side was put on in an identical fashion I think it's an adjustment issue like you two are suggesting. I'll add that onto the "To Do" list for today!

Steve

[=Enigma=]

Maybe it's just the picture but something doesn't look right with that lower spring.

Looks like there's only one way to put the shoes on, could it be that there's left and right side shoes or are they the same for both sides of tha car? I haven't gotten to the brakes on mine yet.

[montoya_fan01]

shoes are the same for both sides. lower spring is correct. upper spring looks different than mine (see mriz post)

[xray]

The shoes are different front vs rear (on the strut), but the same left vs. right. Rear shoe hooks into the e-brake flange (has square hole mounted on it), interfaces with the slot cut in the piston and is slightly longer than its mate which mounts in front and attaches to the adjusting wheel. Top return spring is green and has opposite-ended hooks in an S-type configuration. Bottom return spring has hooks on same side but bent 90 degrees so that they look like eyebrows when the spring is held horizontal.

True, the lower return spring can be mounted anterior, but it is fully engaged and very tight, as my fingers will attest...

FWIW, and messed around with the position of the cylinder in that slot, and that seemed to fix the problem. When turned, the drum slightly scuffs the shoes, and the drum spins as far as the axle without the drum attached...

Of course, all of this is subject to change once the lines get hooked up and bled--who knows what problems still lurk!

Steve

[jmortensen]

I'm not sure what the problem is but be aware that properly adjusted drums SHOULD drag a little. If you can spin the axle with the drum on and it freewheels for 2 rotations you need to adjust the shoes out.

[montoya_fan01]

FWIW, and messed around with the position of the cylinder in that slot, and that seemed to fix the problem. When turned, the drum slightly scuffs the shoes, and the drum spins as far as the axle without the drum attached...

Of course, all of this is subject to change once the lines get hooked up and bled--who knows what problems still lurk!

Steve

I think that is all your problem was. The RWC needs to be centered so the F & R shoes contact the drum simultaniously. Easy for that to be out of whack when assembling the system by hand, but once hydraulic pressure is applied via the RWC, that sorts itself out.

Operating the E brake handle (after everything is reinstalled on the car) will "self adjust" the shoes to the proper contact with the drum

[xray]

I'm not sure what the problem is but be aware that properly adjusted drums SHOULD drag a little. If you can spin the axle with the drum on and it freewheels for 2 rotations you need to adjust the shoes out.

Definitely, but a "too loose" shoe is more easily fixed than a "too tight" one...at least for me

Thanks for the advice!

Steve

[Walter Moore]

A too tight drum will sort itself out pretty quickly once you have a few stops from speed... :eek:

But seriously, almost every time that I have put new shoes on with new drums they have a lot of drag at first.

Now if new shoes are draging on an old drum, then I would be worried.