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View Full Version : Check those Rear Drum Brakes


Rick Anderson
February 27th, 2006, 11:49
Not really a question, more a warning for those out there.

I'm fixing up a '95 XJ w/ 2.5L/AX-5 and 2WD 201k miles, that I bought a couple of weeks ago.

I finally got around to pulling the rear drums off last night (I've been working on the rust holes in the floor pan).OMG, I can't believe my brakes worked as well as they did.

The self-adjusters were 100% SIEZED I could NOT break them free. Springs were bent and one of my wheel cylinders were leaking. I'm collecting the parts now to do a full rebuild (except the drums themselves, since they are pretty good shape, not seeing a lot of use or wear over the years).

Judging from this prevous owner (he said the brake light had been on for the last 50k miles, like it was no big deal and the brake reservouir was completly dry), and other people I've observed, many people don't understand how rear drums brakes work and they often ignore them. Just a tip, properly functioning and adjusted rear drums brakes are critical to maintaining brake pressure up front at the Front Disc Brakes. Ignore the rear drums and they will sieze up like mine and not work properly and your brake performance will suffer. Nothing you do to the front discs to improve brake performance will do much at all, until you deal with the rear drums. If its been a while or if you've never done it, I'd pull off the drums and check the rear brakes out on your XJ.

87manche
February 27th, 2006, 11:51
It's also nice to have functioning drums in the rear when your front rotors get all wet.

Rick Anderson
February 27th, 2006, 12:08
Also nice if you tear open a front brake line. Another thing a lot people don't realize, almost all brake systems are dual, you lose pressure in a line, you only lose half your brakes. Most are front and rear, so if you loose pressure in a line, you'll either have the fronts or the rear brakes still working, which the rears don't make a lot of braking force. Some newer cars have an "X" pattern, front brake shares pressure the opposite rear, so if you lose pressure, you'll alway have a front brake and a rear brake on the opposite side to help counter the pull to one side.

Most XJ's are front/rear split, that I'm aware of.

2001XJeep
February 27th, 2006, 12:27
Rear drum brakes are definitely one of those forgotten areas that so many people never consider. Reminds me of folks that aggressively maintain their brake pads/discs/etc, but never flush the fluid.

I think it's wise to remove the drums, clean everything and manually adjust them about once every six months. At the very least once a year. Rear shoes will usually last 100k miles if this routine is followed.

87manche
February 27th, 2006, 12:31
Rear drum brakes are definitely one of those forgotten areas that so many people never consider. Reminds me of folks that aggressively maintain their brake pads/discs/etc, but never flush the fluid.

I think it's wise to remove the drums, clean everything and manually adjust them about once every six months. At the very least once a year. Rear shoes will usually last 100k miles if this routine is followed.
I've been pulling mine monthly as part of the lube schedule, just to inspect. Doesn't take more than pulling the wheels off. Lube and adjust every other month.

Rick Anderson
February 27th, 2006, 18:57
Well, if you've developed a ridge in the drum from wear, you may have to take a few extra minutes to back off the adjusters to get the drum off, but its still not that much extra.

I usually keep my rear drums adjusted rather tight, so unless my rear drums are new or recently turned, I usually have to back off the adjuster to get the drums off.

87manche
February 27th, 2006, 19:13
new drums :) They pull right off, haven't worn to the point of a ridge yet. :)

5-90
February 27th, 2006, 19:22
I've also found that using dry graphite to lube the adjuster screws works a lot better than oil or grease. Since "wetting" the screws attracts dust and crud, using the dry graphite solves that issue by not letting things get wet, and they'll work better (I've always been able to turn them with two fingers when I tear everything to bits, after I redo them once.)

I'm thinking of going to a Teflon/Moly coat, or a dry Moly coat, so I don't have to keep adding the graphite...

5-90

Rick Anderson
February 28th, 2006, 08:43
Where would you find dry Moly coat??

Its one of those things, darned if you do, darned if you don't. If you lube the adjuster up real well, its collects brake dust and dirt and can jam up. Don't lube it all or very lightly lube it, and it could rust up and sieze.

I've usually just lubed them up real well, wipe off the excess. They do get really dirty and I worry they'll jam, but I haven't had them jam yet, they usually keep working fine. I just bought this XJ used, thats why the adjusters are all siezed up.

I'd considering trying some sort of dry lube, if it protected against corrosion real well.

Xj'sR'Creamy
June 21st, 2006, 09:23
I think that's my problem right now, my adjusters are siezed because when I apply the hand brake parking up a hill, it doesn't hold it anymore and now I rest on my parking gear, which I hate doing so I don't park in the driveway (which is on a slant). I've been meaning to get at er, but it's one of those things that you just don't think of...yet it is very important.

Sean

RyanM
June 21st, 2006, 09:36
so are you letting us know or do you have a question?
jack er up, pull the drums, go to parts store if needed, get r done

FitchVA
June 21st, 2006, 10:11
lol. what a coincidence. i just broke into my brakes this weekend to see why there was a grinding sound coming from it.

found this sitting on top of the brake shoe...

http://viewsfrommylens.com/Gallery/albums/album75/IMG_1487.jpg

the adjuster cable broke...

http://viewsfrommylens.com/Gallery/albums/album75/IMG_1489.jpg

and allowed that piece to lodge between the drum and the shoe...

http://viewsfrommylens.com/Gallery/albums/album75/IMG_1492.jpg

5-90
June 21st, 2006, 10:52
Where would you find dry Moly coat??

Brownell's comes to mind first - it's spendy, but something I'd like to experiment with, and probably worth it, used properly...

I have a habit of using dry lubricants in dusty areas - particularly brakes - just because grease that collects dust becomes grinding paste, and I end up having to replace parts far more often than I'd planned...

5-90

Matthew Currie
June 21st, 2006, 15:19
Adding to the above (I agree, check those brakes, often!), I will repeat an observation I made on my 99 recently. The brakes had been completely redone with all new parts, and the adjusters weren't working at all, because the pivots that insert into the trailing shoes had not been properly installed. You can't tell just at a glance, and the springs hold them in even if they're not properly seated in the hole, but if they're not right the adjuster cable is slack and won't work.