Brake Drum Advice

[jay79cj7]

Well, I need to do the rear brakes on my CJ and XJ... Never done drums before, but I have done discs. I want to get it done before it gets cold out, so one of these next couple weekends I'll do them. I have a Haynes manual for both trucks, so I have looked that over.

Before I dive in, does anybody have any advice for me? Such as the best way to get a rusty drum off a 24 year old Jeep? And which would be the best vehicle to do first? The newer and hopefully less rusty XJ or the older CJ for some practice? Oh, and the XJ has ABS. Any concerns there? The CJ does not . The manual says replace the springs... Is that necessary? I have heard not. I also have heard that I should buy the spring tool, so I plan on getting that.

Thank you, oh wise ones. I have become addicted to this site.

 

[Snitty]

you would be best off replacing the springs on the cj.. not so crutial on the cherokee.. but check them.. if they look bad, replace them... you will likely have to replace the adjuster on the cj... get a can of brake cleaner so you can see what you are doing before you go digging through dust deposits... check your cylinders, make sure you can push them in so they return to the "in" position.. if they are froze up, you will want to replace them

 

[Bounty__Hunter]

The spring tool helps, but I've always managed to get by with a pair of channel-locks and some busted knuckles :roll:

Spray some PB Blaster around the hub where it meets the drum, a day before the planned work.

The ABS won't matter, except maybe when ordering the proper shoes. Just do one side at a time so you have the other for reference. Can't really go wrong there.

Use anti-seize on the threaded self-adjuster at the bottom of each drum.

 

[jay79cj7]

Anti-seize, brake cleaner... check. PB Blaster... That is GREAT stuff, and I will definitely use it here.

Two stupid questions:
1) Can I still drive it safely after putting PB on the brakes?
2) How do you take the drum off? The book makes it sound like it will slide right off.

 

[Bounty__Hunter]

You won't put the PB on the brakes, just around the center of the hub where the drum slides over the hub. That is usally where they rust together.

Yes, the drum is designed to slide right off. If it's hanging on the shoes inside the drum, you'll have to go in through the adjustment hole in the backing plate and back off the self-adjuster.

 

[Joopin]

I just finished overhauling the drum brakes on my dana 44 that I got out of an 89 XJ. It was my first time too. I started it last friday, the first side took me 4 hours! But I wasted an hour trying to put the keeper spring on backwards... and I replaced EVERYTHING. I felt I needed to since I got the rear out of a junkyard. I did the second side today and it took me less than one hour since I knew what I was doing. You will need 2 kits, the spring kit and the sefl adjuster kit. The self adjuster thing was frozen right up on the originals and it was only 15 bucks for a kit for both sides. I did all the spring work with a needle nose vise grips and a regular vise grips and everything went good. One thing I found helpful was using a big C-clamp to hold the shoe to the axle when your putting it all together, otherwise the whole contraption wants to fly apart before the keeper springs are in. Oh and the drums, I got off just by bangin em around when transporting them from the yard to my garage! I think you could just tap around with a hammer, they should come off.

WAIT! When putting the assy. back together... Don't forget to put in the parking brake cable first! It's a pain in the ass to feed it back there behind everything. Good luck!

 

[jay79cj7]

Thanks for the advice guys. Hopefully the weather will be clear for me to get this going this weekend. I don't have the luxury of a garage, so I am at mother nature's mercy.

I have been reading my books... It sounds like the the CJ drums are held on by a couple screws but the XJ's are not. (I have an AMC20 rear in the CJ.) Is this correct? If so, I will need to pull the tires off to put PB blaster on the day before I start. I figure somebody here will know instead of having to yank the tires off just to see during the 10 min I have before it gets dark after work.

Thanks fellas!

 

[Inspector-Gadget]

Hello Jay79CJ7,

To supplement and elaborate on the great posts above, a few thoughts in no particular order:

(1) Your CJ brake drums are indeed held to the hubs by three very large headed "Phillips Head" machine screws on each hub. It is helpful to have a large (#-4) Phillips head screw driver available to remove those screws.

(2) During reassembly you will feel the need of three more hands to hold everything together while you reattach the several springs and gizmos. I have found that using a light-duty ratchet strap around the brake shoes will compress the brake cylinder and help hold everything in place while you complete reassembly. A strong bungee cord would also suffice.

(3) CJ-7 rear brakes came in two flavors. CJ-7s were initially produced with drum brakes on all four wheels. The rear drums on the early CJ-7s were referred to as 11-inch brakes. Later model CJ-7s had disk front brakes and drum rear brakes. The rear drum brakes were downsized to 10-inches when the front disks were added. That difference is brake shoe size might arise when purchasing the replacement brake shoes. On my 85 CJ-7 with the smaller rear brakes, the brake drums are stamped along the outer circumference with "10.6." They are 10-inch brakes.

(4) You probably will experience the "flying spring" syndrome during reassembly, especially likely if you are not using a brake spring tool. Please, wear suitable eye protection during this phase of reassembly. Those springs can and will launch and ricochet around with great force.

(5) Swearing while searching in the grass for those self launched springs is permissible and considered good form. It is easier to be nice to yourself and spare the psyches of nearby impressionable children: buy or rent the proper brake tools at your local AutoZone.

(6) Probably obvious advice, but note during disassembly that the length of the friction material on the forward (leading) brake shoe is less than the length of the friction material on the rearward (trailing) shoe. This is typical of "self-servo" style drum brakes, but an easily missed distinction if this is your first brake job and you are working at night under poor lighting.

(7) A possibility to keep in mind is that upon brake disassembly you might discover that the drums need to be machined or resurfaced. No big deal. Your local auto parts jobber will likely be able to handle that job for you on a one day turnaround and at a nominal cost. If, however, your CJ-7 is your one and only daily driver, you might consider doing the brake job at a time when you won't need the Jeep for a day or two.

I hope the above proves helpful.

Gadget

 

[Bounty__Hunter]

Very good dirtrections, G.

 

[XJNick]

About the ABS, be sure to NEVER compress the calipers (front) or Wheel cylinders (rear) without having the bleeder valve open. Doing so will cause brake fluid to travel backwards through the ABS pump , which can damage it.

-Nick :!:

 

[jay79cj7]

Alright, got my parts, and my brake pliers, after Autozone tried to give me the wrong hardware a couple times... They have the best prices and worst service of the places around me.

I had forgotten about this, but I have a stud that is sheered off (previous owner) on one of my back wheels. How hard is it to replace that while I am in there doing the shoes? I haven't ever been in the back wheels before, and I can't tell from my Haynes.