Refurbing rear 9" drums on my '72 Demon

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72demon-777

72demon-777

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While driving to put my Demon away for the winter this past winter my right rear brake seized up on me just down the road from my storage garage. Pulled it out this Spring to get it road worthy again and fluid in the master cylinder was low. It's time I took my rear drums apart and refurbish what needs to be refurbished to get a some time out of them before I replace my stock rear end with a beefier 8-3/4".

I've purchased new shoes, hardware kit and rubber brake hose. Not knowing what I'm going to find when I take it apart and believing everything to be 1972 equipment, is there anything else that I should anticipate needing or something I should replace now since I'm going to get into it? I've never done work on drum brakes before but do have a mechanic as a neighbor so I'm not completely lost in the woods.

Any advice is greatly appreciated.
 
Redoing the brakes on my 71 dart right now. 9" drums. (7x1/4" rear end) had to get shoes, adjuster spring kit, turn rotors, and here's the tough one, 9" parking brake strut springs. Found 1.
 
Alright, here's the story. Replaced shoes, hardware/springs and wheel cylinders. Adjusted brakes to rub slightly when cars in neutral and bled brakes. When car is put into drive and brake is applied the driver side turns ever so slightly but the passenger spins freely (like car is going 15mph). If I try to adjust brake any more I cant get the drum to slide on. Driver side adjuster shows 5-6 thread, passenger is bottomed out maybe 1 thread.

Repair manual said stop light switch may be adjusted improperly which I know it is because it doesn't contact my brake pedal securely and I shimmed it to make sure my brake lights go off. Can't get to the screw to adjust it because of my fat knuckles. I don't know what impact this would have on my brakes though....

Please help.:banghead::banghead::banghead:
 
72demon-777 said:
Alright, here's the story. Replaced shoes, hardware/springs and wheel cylinders. Adjusted brakes to rub slightly when cars in neutral and bled brakes. When car is put into drive and brake is applied the driver side turns ever so slightly but the passenger spins freely (like car is going 15mph). If I try to adjust brake any more I cant get the drum to slide on. Driver side adjuster shows 5-6 thread, passenger is bottomed out maybe 1 thread.

Repair manual said stop light switch may be adjusted improperly which I know it is because it doesn't contact my brake pedal securely and I shimmed it to make sure my brake lights go off. Can't get to the screw to adjust it because of my fat knuckles. I don't know what impact this would have on my brakes though....

Please help.:banghead::banghead::banghead:
Click to expand...

Air still in the system.
 
72demon-777 said:
When car is put into drive and brake is applied the driver side turns ever so slightly but the passenger spins freely (like car is going 15mph). If I try to adjust brake any more I cant get the drum to slide on. Driver side adjuster shows 5-6 thread, passenger is bottomed out maybe 1 thread.
Click to expand...

Are you saying with the brake pedal pushed down the wheels are turning?
Did you make sure the parking levers were in the fully released position? The shoes should contact the extensions coming out of wheel cylinder and actually push it into cylinder. Could be you have a cable or cables not operating correctly. You can go about it a couple of ways. First you could unhook the cables from the park brake lever on the brakes and see how they adjust. Or you could physically try and push against the park brake levers to see if the cable extends any more. How does the brake pedal feel when you push it? If you replaced the wheel cylinders you may still have air in the system also like stated above. Just trying to pull some more info out.
 
Don't adjust the shoes until they "barely touch." Adjust them fairly tight, making sure the brake cable is loose, and then BACK THEM OFF equally both sides until they lightly rub.

What are you doing about drums? Old ones turned? New drums? As the old drums wear and are turned, they get LARGER which means the "new" shoes don't fit properly and "hit" only in the middle. Years ago, you had the shoes "arced" on an "arcing machine"

...........One of these horridly awful, dirty machines. Yes, I've been there done that. In a previous life, I've turned literally thousands of drums and rotors, relined (riveted) shoe lining and misc. brake bands

Ammco_890_Brake_Shoe_Grinder_Stock_401_p1_w500.JPG
 
The drums were not replaced. I'm attempting to get one more summer (maybe two) out of the 7 1/4" until I can upgrade to an 8 3/4".

To add, when I start the car (it's currently on jack stands) and place the car into drive, and then depress the brake, the drivers side rear drum spins a tiny bit as if the brakes are applied but not quite enough to cause the drum from spinning entirely. The passenger side is a different story, it spins as if I am coasting down the road.

I did not replace the wheel cylinder on the driver side as it appears to be working. The cylinder on the passenger side was shot and had to be replaced. The brake pedal is firm when I engage it, it does not fade. I have engaged and disengaged my parking brake and do not believe that it is partially engaged.

I will attempt to bleed it some more tomorrow, it is possible that it could still have some air in the lines from running it before with the bad wheel cylinder that wasn't removed when I replaced the new cylinder. I'll update as I can. Thanks for the help.
 
72demon-777 said:
The drums were not replaced. I'm attempting to get one more summer (maybe two) out of the 7 1/4" until I can upgrade to an 8 3/4".

To add, when I start the car (it's currently on jack stands) and place the car into drive, and then depress the brake, the drivers side rear drum spins a tiny bit as if the brakes are applied but not quite enough to cause the drum from spinning entirely. The passenger side is a different story, it spins as if I am coasting down the road.

I did not replace the wheel cylinder on the driver side as it appears to be working. The cylinder on the passenger side was shot and had to be replaced. The brake pedal is firm when I engage it, it does not fade. I have engaged and disengaged my parking brake and do not believe that it is partially engaged.

I will attempt to bleed it some more tomorrow, it is possible that it could still have some air in the lines from running it before with the bad wheel cylinder that wasn't removed when I replaced the new cylinder. I'll update as I can. Thanks for the help.
Click to expand...

Maybe it has just been my luck but every time I replace only one wheel cylinder shortly the other side starts leaking. I was always told that they were to be replaced in pairs so now I always do that. It just is too much work to tear the brakes down a second time as cheap as new wheel cylinders are.
 
Yeah, in retrospect I should have done that. I replaced driver side setup first then found the destroyed wheel cylinder when I took apart the passenger side. By the time I'm done I'll probably have taken each side apart about 12 times so I should be pretty quick at it.
 
Alright, tried bleeding the brakes again this evening. I'm getting drips out of the rear both left and right. Bled the front driver side and it squirts right out. Broke the bleeder valve on the front passenger side so it looks like I'm replacing that wheel cylinder tomorrow (hopefully).

Why am I not getting anything out of my rears? When I bled them the first time my neighbor (who is a mechanic and has done this before) did notice air bubbles from the hose into the brake fluid bottle we rigged up.:banghead:
 
72demon-777 said:
Alright, tried bleeding the brakes again this evening. I'm getting drips out of the rear both left and right. Bled the front driver side and it squirts right out. Broke the bleeder valve on the front passenger side so it looks like I'm replacing that wheel cylinder tomorrow (hopefully).

Why am I not getting anything out of my rears? When I bled them the first time my neighbor (who is a mechanic and has done this before) did notice air bubbles from the hose into the brake fluid bottle we rigged up.:banghead:
Click to expand...


If you are getting air bubbles then there is still air in the system. Give us a detailed post on how you are bleeding the brakes.
 
You said previously that one wheel would brake and the other one wouldn't so you were getting some fluid back there. It may be possible that you need to replace the rubber brake hose.

Here is a pretty decent video on bleeding the brakes. It shows disc brakes but it would work the same for drum brakes.

The only thing I do different is have who ever is in the car to pump the brakes before holding the pressure on them.

[ame="http://www.youtube.com/watch?v=lPwM2vn3bT0"]How to Bleed Disc Brakes - YouTube[/ame]
 
When we initially bled the brakes we did it just how the video showed except that we'd pump 3 times then hold. Initially there were some bubbles then no bubbles so we presumed we were good. That was done on just the rears. When car was in drive and brake applied left would stop, right kept on spinning. That was what prompted my initial post. Since that, we attempted to bleed the brakes again. This time, to start we did not attach the bottle but pumped and held and opened the bleeder. Nothing but a drip came out the rear on both sides. We went to the front and did the same operation and as soon as the valve cracked brake fluid came spurting out. Now when the car is put into drive and the brake is applied, it's the exact opposite, the left spins and the right doesn't. It makes no sense. Add on to that, when I tried to crack the right bleeder, it sheared off with no effort whatsoever. I bought a rubber brake hose anticipating it needing to be replaced, but it looks to be in real good shape. I will replace it just to be safe and re-bleed and let you know what happens.
 
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