BradyB

Brake Drums are just about the only negative things associated with driving classic cars, I sure do hate them.

I bought my 63 88 a couple weeks ago and it's awesome. But twice the rear passenger drum has overheated and started dragging. It gets hot and starts smoking. Last time I had to use a bar to leverage off the drum, the brakes wouldn't release. The shoes are supposed to come back together and meet together up at the top of back plate and they weren't, they were staying about half an inch apart. I turned the reverse adjustment all the way in and they still wouldn't come together. I pulled all of Satan's springs and it looked like either the parking brake was hung up and not releasing all the way (I didn’t use the parking brake), or the cylinder wasn't allowing the shoes to come back together-like brake pressure was still being applied by the power brakes?

So for you white-haired Gentlemen, what would you do and start replacing? I've been real gentle on the brakes and it happened again yesterday. After I let it cool down it seems to be okay and it no longer is dragging.

redoldsman

This old gray haired guy would replace the wheel cylinder and probably the rest of the hardware (springs and retainers). I would also replace the rear hose. I would go ahead and do both sides. Get some brake cleaner and clean everything after you take the drum off.

Good luck.

BradyB

I hate to ask but if that rear drum is now warped would I have a chance of finding a cheap replacement?

What bolt pattern does my car have, a 5x5?

MDchanic

It's not likely to be warped. These aren't girly little rotors, you know.

- Eric

redoldsman

Very true. You can cut a lot of metal out of these old drums. Of course due to its age, it may have already had a lot of metal cut out.

I don't know who makes a replacement and if you find one it won't be cheap. First thing to do would be to have drums checked and see if they can be turned. The quality of the original drums will be better than anything you might find today that would be made in China.

jaunty75

Kanter sells them. They're a well-known, respectable company and have been in the restoration parts business for many years. Cost is $99 per drum, which I don't think is that bad for something new.

http://www.kanter.com///productdetai...0&Cat=6&Prc=35

While you're replacing the drums, I'd do the entire brake on each side. Get new shoes, hardware (springs, clips, and all), and new wheel cylinders. These cars are very easy to work on, and I think you would be much happier with a good set of fresh rear brakes.

MDchanic

If you even need to replace the drums.

Why not figure out what's wrong first?

When the wheel cylinder is tight, try loosening the bleeder fitting on the back - if brake fluid squirts out and the cylinder returns to its resting position, the problem is a swelled brake hose acting as a check valve.
If nothing happens, then the pistons are probably tight in the cylinder and it needs to be replaced - remove the shoes and the cylinder and check for corrosion / free movement.

- Eric

BradyB

Very smart, I'll try that.
For the rear hose, shoes, hardware set, and a pair of cylinders it's only about $83!

Mikes65

I would bet on the emergency brake cable
If you do not use it they eventually corrode
If you or someone hit the pedal once it can still return even though the cable is stuck

droldsmorland

X2 on replacing the cylinder & hoses (all 3). But first check to make sure the primary and secondary shoes are in the right orientation. The small shoe is the primary and it faces the front. Larger secondary goes to the rear.

redoldsman

I think all of this is really good advice. Keep us posted as to how you come out.

Lady72nRob71

Also, with it assembled, drum off, take a look where the shoes rub on the backing plate. There should not be any abnormal deep wear at those points.
I would do this in the driveway. Spray the parts down with simple green, then hose off all the brake dust. You will be able to check the backing plate areas and not have to worry about breathing in any of that fine dust when taking it apart. YOU stay cleaner also.
A tad of brake grease will need to be applied on the backplate in the shoe contact areas after cleaning, before installing new parts.

Drum brakes are perfectly adequate for most normal driving. Discs are better in cities with higher speed limits and lots of lights or traffic (like the DFW area)...

oldcutlass

Also make sure the rear adjuster is operating and assembled correctly.

oddball

So I just re-read the service manual sections on the drums this past weekend, and noticed there was a big warning that mis-assembling the rear drums will cause them to continually adjust and stay engaged.

Maybe as simple as closely check and make sure everything is in the right place?

Creativeindy

When I first bought my 442 I noticed the brakes sucked bad and make a grinding sound and a loud thump or clunk every so often under release of brakes worse when going around a corner. It would lock up the rear drum every so often as well as cause it to over heat. When I was doing my brake job I noticed that the passenger side had the parking brake spread bar that has the spring on one end and it slides inbetween the shoes at the top under the spring pivot. It's a long bar with 2 fingers on each end and 1 end has a spring on it. I noticed my passenger has this but drivers was missing the spring that goes on 2 of the fingers on one side towards parking brake actuator on shoes. I ended up fiding one similar to it at Lowes and it stopped the loud clunking,thumping sound and hasn't locked up since.


Even though that sound is gone I now have the shoe on backing plate griding/sticking sound. It's what is causing my brakes to drag real bad. I tried wet sanding the plate to smooth it, used lithium grease on it where shoes rub it and still did no good. I hate drum brake systems I guess thats why I bought a disc conversion kit.

I originally thought about Erics response about brake rubber lines swelling acting as a check valve. I had an 86 firebird do this it would get the rotors red hot whikle driving. Only way they would release is if I poured water on lines and calipers. Problem with this is on the rear of the cars there is no rubber to swell or collaspe. All my brake system is brand new from master, to lines, springs, clips, to wheel cylinders to drums etc.

If you find out whats causing the drag I would surely love to know as it sounds identical to my cars sound. Well, outside of the red hot locking up part. Mine doesn;t lock up it just grinds bad like its down to rivets even though the entire brake system is new.

BradyB

I know exactly what you're talking about. My car sounds the same going around corners, now I have a rear vibration on braking too. When I pried off the drum, it looked like the parking brake was keeping the shoes from coming back together. I ended up disassembling everything on that one side twice, after banging and pulling on everything I got it to go back together finally because I banged the parking brake enough times or the wheel cylinder finally retracted.

My thoughts on the reasons:

#1 Springs are wearing out, when the drum gets hot the springs loose a bit more tension and they can't pull the shoes back in.

#2 The parking brake isn't releasing 100%. The car is a clean El Paso car, it doesn't look rusty.

#3 The wheel cylinder isn't retracting all the way.

I'm going to replace everything because all the parts are so dang cheap but I'll let you know what I find out. I'm guessing the springs are just worn out.



I bought new shoes, hardware, and a rear rubber hose. The rear hose is only about a foot long but it has a center T block that connects forward.

MDchanic

It's times like these that I wish I could just say, "Take a spin by my place."

Most of this stuff is probably fairly simple to fix, once someone who's done a lot of drums takes an actual look at it.

- Eric

MDchanic

Not likely. New springs are always a good idea, but you can cross this one off as a cause.

Neither does my car, and it's made of rust.
It doesn't matter how much rust is anywhere, other than inside the cables themselves.
If previous owners were the type who never set their parking brake, then it might not have moved at all in forty years. That's enough time to develop some fairly serious rust in there.

I would have a buddy apply and release the parking brake while you look for movement on both sides, and watch the cable from underneath.
Only takes a few minutes, and then you'll be sure.

You'll know this as soon as you take it apart.

- Eric

BradyB

I got her apart and back together this past weekend. It was the cylinder not pulling back in all the way. No more dragging and the brakes are nice and smooth with the machined drums and new pads.

Lady72nRob71

Great - glad it is fixed!

Run to Rund

I hope you replaced the springs too.