Drum Brakes Sticking

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JamesAutumn

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I have a 1973 Plymouth i'm currently turning into a Daily Driver once again. I've replaced the back brakes and one rear drum [in the process of ordering another drum].

My current issue is on the drivers rear side i my brakes are sticking, thus causing it to burn up the brakes and possibly the cause of my car wobbling [Maybe mostly due to the bad drum as well]. Would the brake line on that side be collapsing and causing the brakes to catch and not release?

Any help you can give is greatly appreciated! -- J
 
Anything is possible, but considering the line to the wheel cylinder is steel I'd think it would be leaking before getting to that point. Possibilities are the rubber line to the tee on the rear end housing could be coming apart acting like a check valve and one side being adjusted tighter. My thought is what kind of shape are the emergency brake cables? Sounds like the drivers side is frozen and holding tension.
 
Between me and my uncle, we pressed the brakes and felt the drum tighten up like no other. Once we got it off and back on it was like normal. Then pressure and drum wouldn't move.

My uncle is guessing it's the line i believe he clamped it shut and unclamped it to come to that conclusion. We checked the metal parts of the lines on the car and no leaks or damage. The rubber hose coming to the wheel cylinder might be damaged or clogged inside?

Also it's a 1973 Plymouth Valiant Slant Six 225. The Emergency brake hasn't worked since i've owned it [another item on the checklist to fix]
 
Better watch that line where it was clamped no matter what else you find.

If it's a line causing it cracking the line to that wheel cylinder while it's bound will release it.
If it doesn't release then you know it's a mechanical issue and not a hydraulic one.
Once you prove which it is, track it down.
 
Have you rebuilt or replaced the wheel cylinders? If not, then that could well be the source of the problem. For a car that old, not rebuilding or replacing all the wheel cylinders is asking for trouble.

And be aware that the spring shave to be right and matched. You may have flipped some of the springs; they have to be exactly right.

Also check the new shoes; there is a primary and secondary on each side and the primary has to be the front one; if you reverse them, then you will get the drum grabbing.
Does this car have drums or discs up front?

You post may be a bit confused on one count: there is only one rubber line to the rear and that feeds both rear drums. And, if your uncle clamps any more old rubber lines, he needs to just go out and but replacements. Clamp[gin old rubber lines is a great way to finish them off in a way that locks brakes on.
 
If he did some damage i'll be sure to give him an ear full about it and possible get some free parts [that weren't needed probably]. We followed the pattern of the old shoes that came with the car and each side puts the Shoes that attach to the springs to the rear.

When i looked at the rear driver side brakes the ones facing towards the front had a area shaved off at the bottom end and looked like light grooves where the drum may have been warping and rubbing in on it?
 
The shorter shoe material is common for the primary side pad that faces to the front, so that sounds OK. The passenger side should be the same.

Are you saying that the front shoe on the drivers side rear was worn unevenly, with the bottom worn badly? I can only guess at why may have caused that:
- Perhaps the front piston in the wheel cylinder is not moving and is frozen in with rust.
- The adjuster (that contraption at the bottom between the shoes) is missing the spring around it.

The springs sounds good, but be aware that they can get weakened and not work right. I have not ever read of any way to test them, so it is best to just put new spring kits in.

As for the hose, if it is old enough to be damaged by clamping, then it is old enough to need replacing it anyway. For a car likethis, all 3 rubber hoses shoudl be repalced (2 front, 1 rear). The clamping just makes it obvious faster! The issue is that the inner lining get hard and brittle and falls apart and pieces get jammed inside and block the brake fluid. And as said, for the rear brakes, it would effect both rear brakes, not one side.

Again if you would not mind answering:
- Drum brakes all around?
- Wheel cylinders rebuilt/replaced?
 
Sounds like a bad wheel cylinder. I assume the springs on the crimes are right.
Star key operating well? Installed correctly? I have seen these installed improperly or malfunction.
 
A couple of questions i can answer to the best of my ability is: 1. The wheel cylinders have been replaced along with the brakes each time i've done a new set. I do this for my own sanity of having a safe car as possible, plus the other ones either burnt up or malfunctioned anyways. 2. Yes Drum Brakes all around. I don't even have a brake booster installed. [another item on the list to buy]

I am in the process of ordering another drum and brake shoes along with a spring kit for the driver rear side. It's my hope that this will fix the wobble and the burning and sticking issue. Burning attributed to the warped drum and shows sticking i'm sure so that knock those two out, 3 for 3 right?

As far as lines are concerned. When it stops raining and snowing outside [can't fit in the garage due to my families crap we never look at] I'll take a thorough look and make sure those aren't the original lines, which is my fear but also my amazement that these factory parts have lasted so long.
 
Check the wheel cylinder to see that the pistons inside it move freely and don't hang up with your fingers. If it's not smooth, then you need to replace them.

Or also, have you cleaned and greased the 6 contact spots on the backing plates where the brake shoes ride? They need to be cleaned and a light coat of axle grease on the 6 flat spots on the backing plates so the shoes move freely.

Then, check to make sure that you don't have a pinched brake line that could be restricting the fluid flow (steel or rubber)...
 
@krazykuda Thanks i'll check it out soon as i can! All the advice i've gotten so far is definitely giving me ideas to get this beauty on the road again
 
Or also, have you cleaned and greased the 6 contact spots on the backing plates where the brake shoes ride? They need to be cleaned and a light coat of axle grease on the 6 flat spots on the backing plates so the shoes move freely.

This is good advice, but first check to see if the backing plates don't have deep worn spot, "divots" into them, where the shoes have been for decades.
If the divots are deep, they need to be welded up, and ground smooth so the shoes can move, and then retract.
Have seen too many worn backing plates, when i was a full time wrenching, mechanic.
 
RUBBER LINES.....replace them. this just happened w my nephews 71 dart. $12. fix!!
 
This is good advice, but first check to see if the backing plates don't have deep worn spot, "divots" into them, where the shoes have been for decades.
If the divots are deep, they need to be welded up, and ground smooth so the shoes can move, and then retract.
Have seen too many worn backing plates, when i was a full time wrenching, mechanic.

Yes, I didn't mention to check the 6 flat spots on the backing plates for worn ridges. Great point to weld/grind smooth as needed.

Jim knows brakes.... :sign7:
 
Or also, have you cleaned and greased the 6 contact spots on the backing plates where the brake shoes ride? They need to be cleaned and a light coat of axle grease on the 6 flat spots on the backing plates so the shoes move freely.
I would suggest using brake caliper pin grease if some is readily available, rather than axle grease. Either way, put just a minimal amount on the 6 spots; don't slather it on.
 
Latest Update:

Replaced all the springs, shoes, and drums on the back of the car. The wobble is gone. The right side is perfection. The left side doesn't stick anymore, but, but, but!!!!! it is still somehow smoking when i take it down the street and back so i dunno what's up! Any ideas?
 
Primary shoe (short one) goes on the front. There are two primary and two secondary shoes in a kit.....
 
I'd like to think after replacing the brakes 4 times during this problem i'd get it right lol I could check to see if the proper sides are on
 
Latest Update:

Replaced all the springs, shoes, and drums on the back of the car. The wobble is gone. The right side is perfection. The left side doesn't stick anymore, but, but, but!!!!! it is still somehow smoking when i take it down the street and back so i dunno what's up! Any ideas?


What is smoking?

Do you smell hot friction material, it has a distinct smell. There may be a shoe dragging or maybe you have the adjustment a little tight.
 
I'd like to think after replacing the brakes 4 times during this problem i'd get it right lol I could check to see if the proper sides are on


The shoe with the shorter pad goes on the front, and the longer pad goes on the rear...
 
The drum that replaced the original [shocking i know but according to research i've had the original factory drums all these years] is more sleek or smaller in design? The self adjuster is dialed all the way back, meaning it's not expanded one bit. The brakes aren't tight when putting the drums on though, it seems to feel just right.

The shorter pad is where it should be so everything seems in check. I think it is a friction smell. It smells like smoking breaks but then has a somewhat sweet odor? if that helps out.
 
The drum that replaced the original [shocking i know but according to research i've had the original factory drums all these years] is more sleek or smaller in design? The self adjuster is dialed all the way back, meaning it's not expanded one bit. The brakes aren't tight when putting the drums on though, it seems to feel just right.

The shorter pad is where it should be so everything seems in check. I think it is a friction smell. It smells like smoking breaks but then has a somewhat sweet odor? if that helps out.


If there's nothing hanging up and everything is clean and properly lubricated, then it shouldn't hang up unless there is a problem in the master or wheel cylinders. If you checked the wheel cylinders for freeness by stroking them from side to side with your fingers, then they should be fine.

If it's not too bad, then maybe you just need to drive it a little bit to break in/wear in the new pads...
 
My dad, a mechanic of 40 years just mentioned that about breaking it in @krazykuda i might have to listen for once and give it a shot. Thanks for the advice on that. When the weather is less icy and rainy i'll test it and update you guys on it. Thanks for the comments and lessons i'm learning a lot!
 
........Did u check to see if the emergency brake cable is not slightly seized on a little........u need to adjust ur shoes out to have a slight drag......show us some pics..................kim..........
 
You know, I haven't read anything yet about flushing the brake system BEFORE you replace any hydraulic parts, as any contamination in the brake lines will just get pumped into the new parts. This can cause the system to fail, even though you replaced everything. To make sure that everything is up to snuff, I would take the drums to a local machine shop or repair shop that does brake jobs and have the run-out checked on the NEW drums. Are they imports or oe type ? Brake lining type ?Brakes systems are very basic. Just start at the beginning and don't ever assume anything. Check each part before you install it to make sure there are no problems. Then if you have to diagnose a problem later, you will know for sure that you already checked that item. Take every thing off and start over. If you don't have one, go on line and look up your year and model of brake system you have and just print out the pictures and the printed info. Again don't assume anything. Take your time. Enjoy.
 
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