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Rear brakes 9" or 10"?

B

bradleyheathhays

NAXJA Forum User
Location
Lexington, KY
About to do the rear drum brakes on the old '96 XJ for the first time since I got it in 2007. Went in to O'reiley's for parts and they asked me to identify whether it was the 9" or 10" version...didn't know there was more than one size for my year.

How do I know what size brake I have?

Also, they're asking me if I want to replace everything...shoes, drum, etc, etc. Since it's been so long since the rears were done is there anything back there I can get away with not replacing? Or should I just do a full swap out of everything in the brakes I can get to? What's the name of all the parts I should be getting?

This'll be the first time I've done rear drum brakes so any additional advice would be muy helpful.

Thanks
 
The 9" drum is smooth. The 10" drum is ribbed. You likely have the 9". Post a pic of the drum and we can tell you for sure.

Edit: I would get shoes and drums.
 
I bought a full hardware kit, shoes, wheel cylinders, and the adjuster bits. Drum brakes aren't hard (lots of writeups and pictures, all over the net), but I think they're a PITA, and I'd just as soon replace everything once, than have to tear them apart multiple times (deciding the wheel cylinders were "good enough" has bitten me twice).

I still have my original drums at 215K. Everything else besides the backing plates has been replaced now. YMMV.
 
Been my experience the rear drums don't wear much. The exception being they can get grooves worn in them. You can have them measured at the auto parts store, they have a wear gauge or you can mic them yourself if you have the tool. You have to make a judgment call on whether the grooves are bad enough to worry about or not, I've never known them to be much of an issue.

I've only replaced one drum on three XJ's and that was because I dropped it on the concrete and broke a decent sized chip out of the edge.

I've been hoping to find a spring kit, been my experience the springs rust and corrode bad, way before the drums wear enough to replace. Especially in salt country.

If you find a spring kit please get the part number for me. My parts supplier only wants to order and sell the springs individually.

Not that big of a deal to change out the shoes and hardware, just notice which shoe goes in the front and which in the rear, the shoe pads are two different lengths, the shoes themselves the same length. Do one side at a time so you have something to look at and compare if you get brain lock.:)

There are a few tricks and techniques to getting the springs on and off. Either a you tube video or a friend that has done it before could be helpful.

Changing out the wheel cylinders can be like having sex with a Kangaroo. It may seem like a good idea until you try it. Getting the brake line off of the wheel cylinder often turns into a real pain for many people. I've been lucky so far, I've seen many of people screw this up.

I carefully pry open just a tiny crack in the rubber dust cover on both ends of the wheel cylinder, if no fluid comes out you are good to go. The down side to not doing the wheel cylinders is if they spring a leak after you have your new shoes in there, they may leak all over your new shoes and ruin them.
 
Should be 9". I think the police package got bigger drums
 
Thanks for all the information everybody. All good advice.

I've been told that I might want to buy the disc brake replacement kit for my drum brakes and install that instead. Is it worth it? Who makes these and where are they sold?
 
pretty sure the 8.25 had the 8" and the D35 had the 9". but always trust your own tape measure above all others.
assuming you know, at least in theory, how to do the job. i would plan for new shoes and full hardware kits and wheel cylinders for both sides. before you do the job try to pull the wheels and drums off to inspect everything. if you have the $$ and want the piece of mind i'd just do the drums, but if you are budget minded, i'd look at them first and decide from there.
also, only do one side at a time......
the springs can get confusing even for experienced people, and having a reference to lok at rather than finding pics on the interweb is a big help.
remember, each side is exactly the same using the front of the Jeep as a reference. NOT the right or left side of the backing plate as you face it.
 
One thing about the drums is as they wear they actually get a larger diameter. The new shoes on old drums are unlikely to fit exactly.

You can get the new shoes re-arched to fit the old drums or you can install the shoes and let them wear themselves in. Rear braking may diminished some for a couple of weeks or a month. I've never found it to be much of an issue letting the shoes wear in to fit the old drums.
 
measure the inside diameter of the drum, should be 8" but you need to confirm

if you haven't done the brakes in a while you should do whatever looks like it would be better off replacing. some of it will break when you try to remove parts.

parts to look at would be the brake shoes, dampness around the wheel cylinders (rust under the seal and start to leak), automatic adjusters (lube the threads before reinstalling), brake lube for the moving parts. You may need some small lengths of pre-made hard line and a bender if your cylinders have rusted to the line. If you ran a shoe down to the rivets or see any kind of scarring on the drum, you should replace them too--paint them with very-high-temp rattlecan (not the friction part obv) to keep them from rusting so fast
 
8Mud said:
Been my experience the rear drums don't wear much. The exception being they can get grooves worn in them. You can have them measured at the auto parts store, they have a wear gauge or you can mic them yourself if you have the tool. You have to make a judgment call on whether the grooves are bad enough to worry about or not, I've never known them to be much of an issue.

I've only replaced one drum on three XJ's and that was because I dropped it on the concrete and broke a decent sized chip out of the edge.

I've been hoping to find a spring kit, been my experience the springs rust and corrode bad, way before the drums wear enough to replace. Especially in salt country.

If you find a spring kit please get the part number for me. My parts supplier only wants to order and sell the springs individually.

Not that big of a deal to change out the shoes and hardware, just notice which shoe goes in the front and which in the rear, the shoe pads are two different lengths, the shoes themselves the same length. Do one side at a time so you have something to look at and compare if you get brain lock.:)

There are a few tricks and techniques to getting the springs on and off. Either a you tube video or a friend that has done it before could be helpful.

Changing out the wheel cylinders can be like having sex with a Kangaroo. It may seem like a good idea until you try it. Getting the brake line off of the wheel cylinder often turns into a real pain for many people. I've been lucky so far, I've seen many of people screw this up.

I carefully pry open just a tiny crack in the rubber dust cover on both ends of the wheel cylinder, if no fluid comes out you are good to go. The down side to not doing the wheel cylinders is if they spring a leak after you have your new shoes in there, they may leak all over your new shoes and ruin them.
Click to expand...

http://www.oreillyauto.com/site/c/s...year=2000&make=Jeep&model=Cherokee&vi=1363384 I've got no idea if they'll ship to Germany or not though.
 
Figured out I got the 9" version. I'd like to do the disc conversion but since everything is still just all stock I'm opting for the slightly cheaper drum/shoe/wheel cylinder kit from Rock Auto...

https://www.rockauto.com/catalog/moreinfo.php?pk=5912082&cc=1180314&jnid=454&jpid=0

Just to make sure, is there anything else I'll need to order or does this kit replace everything that can be replaced? Best I can tell this is all I'll need, plus some speed bleeders maybe.
 
The reinforced brake line sounds like a good idea. I'll prob go ahead and replace those too.

Is there a cheaper alternative to name brand speed bleeders? Does Dorman make the same thing possibly?
 
speed bleeders are a waste of money unless you are going to do alot of regular brake work or there is no chance of anyone being able to help you bleed them.
 
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