Drum Brake Rebuild

**72-SS-L48** · #1 10-15-2013, 01:12 AM

While I have lots of experience on disc brakes, I have limited on drum brakes... Enlighten me!

I need to replace the front drums. The car pulls hard to the left when you hit the brake pedal. What typically causes that type of dive? What should I look for, what is involved with the process?

Thanks,
Dave

**PxTx** · #2 10-15-2013, 01:24 AM

Usually the pull is a result of the other side not stopping equally. Frozen wheel cylinder, leaky wheel cylinder, improper adjustment are a few places to start.

Why do the drums need to be replaced?

**72-SS-L48** · #3 10-15-2013, 01:29 AM

I should have been more specific. I'm not concerned with the drums themselves, just need to rebuild the setup. I have new wheel cylinders, springs and shoes should I need them. I can cut the drums if those are in need.

Best,
Dave

**PxTx** · #4 10-15-2013, 01:58 AM

I would start with a quick visual inspection. Take the drum off. Look dry? Peel back the dust boot on the wheel cyl- hopefully it is still dry. Compare the springs and such from the working side. Then check the adjustment and make sure both sides are close. If things look good, have someone hit the pedal and see if both sides engage.

So is this a recent development? What type of car is this... daily driver, show, barn find, etc?

**Lynn** · #5 10-15-2013, 02:04 AM

Most common cause of pulling hard to one side is the brake shoes installed backwards. The shoe with the longer lining goes in the back. Easy to get mixed up.

Drum brakes are incredibly easy to rebuild, especially the fronts since you don't have to wrestle the park brake lever and strut into place.

Helps if you have two special tools, but can be done with pliers... just a bit more trouble.

Two tools are pictured (yes, I know there are three, but two are for the same thing, just different brands).

The two silver tools are used to remove and replace the return springs. Place over the stud that the springs hook to and twist. Spring will pop off. To reinstall, use the other end. Slip it through the hook on the end of the sping, slide the end of the tool over the stud, pull the handle toward the stud and the spring will pop on.

The shorter of those two is a Corwell, purchased in the fall of 1971. The longer is a MAC, purchased when I misplaced the Cornwell. I prefer the Corwell because it works either left or right handed. It is also closer to 90 degrees bend, so you get better leveridge. Look at the blurry (sorry) close ups and you will see the MAC is beveled on one side only. It only works right handed.

The red handle tool is for removing the hold down springs. Put one hand behind the backing plate to stabalize the retaining pin, press down on the spring retainer with the tool (it has tiny teeth to grip the retainer) and twist 90 degrees. This is a MAC tool, also purchased fall of 1971. I have tried Snap-On and many other brands, but always went back to the Cornell return spring tool and the MAC hold down spring tool. No other hold down spring tool I ever used held the retainer cap like this one does. Probably not as important to a hobbyist, but when you are doing 3 and 4 brake jobs a day, it makes a huge diffenence. I could do a brake job on a disc front drum rear GM car in one hour, and that included turning the drums and rotors and repacking the front wheel bearings. It also helped that the brake lathes were in my stall.

I did somewhere in the neighborhood of 1000 brake jobs with these tools and they are not worn out. Used them on my 69 Z just last spring when it was coming together.

VintageMusclecar · #6 10-15-2013, 02:11 AM

Don't forget to check the hoses.

**72-SS-L48** · #7 10-16-2013, 01:29 AM

I just took my 71 El Camino out of storage and notice the dive. The previous owner did the brakes before I bought it and to be perfectly honest I don't recall if there was a problem or not. After I got the car it went right into storage.

I have not even had a chance to pull the tires and drums to inspect. That will obviously be my first step. It was just more convenient for me to pick up the parts since I had some errands to do near the auto parts store last week. Worst case I add the parts I do not use to my to my stock.

Once I can inspect I'm sure I'll be all set. Thanks for your help!

Best,
Dave

**Lynn** · #8 10-16-2013, 03:12 AM

Like Eric said, don't forget the hoses. They can deteriorate and collapse over time. NORMALLY they both go, but it is possible for one to be restricted with its own innards coming apart.

**72-SS-L48** · #9 10-27-2013, 12:22 PM

Hi Guys,

Yesterday I had a chance to work on the car. I had to replace both front hoses and the driver side wheel cylinder. It's very easy to work on drum brakes.

The car does stop straight but I find the the pedal is soft and moves to the floor too quick in my opinion. I'm going to adjust the shoes and probably bleed the brakes again. Also going to inspect the rear brakes. Any other suggestions?

Thanks,
Dave