• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Rear brakes only last a few hundred miles before pulsing!

@

@dam

NAXJA Forum User
Hi guys. 95/sport/5-speed/no ABS.

My rear brakes have pulsed for a long time. It isn't felt in the pedal or wheel, but in the rate of deceleration. Once per revolution, your head gets thrown forward a little. It's only noticable at low speeds. When it's slick out, these spikes in brake force make the rears lock up very easy, so it's not only annoying but a safety problem.

I took it to a local shop and had new shoes put on and the drums turned. It was fixed for a few hundred miles, and then was back worse than ever. It was so bad that it eventually started pulsing while COASTING- no pedal application at all! It's done this THREE TIMES now. The shop just throws on new shoes, but I'm tired of wasting time here. I need to tell them what the root cause is. Any ideas? Please help!
 
buy a spring rebuild kit for your drums. i think they are $15 tops. then check if the wheel cylinders have free range of motion. but be careful because the pushrods can come all the way out and get brake fluid everywhere. sounds like the brakes are not returning all the way.
 
The original service included a spring kit. The shop said the cylinders look good. How do I check if they have full range of motion?
 
youll need a partner to work the brakes. pull the drum then the adjuster and have partner push brakes. watch the pushrods on the cylinder cycle. if they dont go in and out all the way with help from you just replace them. they are cheap. i think my buddy just paid ~30 for each of his. i hate drums! hell you might even have a bad wheel bearing. check that while in there. or you could find a different mechanic!
 
Last edited:
Check where the shoes meet the backing plate if it's rusty the shoes can hang up and cause rotational noises. I like to pop the shoes off and clean the tabs on the shoes and the backing plates in the points they contact one another with a die grinder. Then I put some brake lube (like the kind you'd use to grease up caliper slides) on the backing plate in the spots I ground. While you have everything apart check the free play in the e brake cables, they could be contributing to the problem if sticking. Once all back together make sure you don't over tighten the shoe adjusters, too tight can also lead to accelerated warping of the drums. Hope any of this helps!
 
"Back in the Day" it was common practice to arc the brake shoes to match the drums.

Description: http://model-a-wis.com/brakearc.pdf

This is not a very common procedure anymore, some call it "controversial", but it did produce the best drum brake jobs.
 
Another thing that can cause problems is to get the brakes overheated some and then put the parking brake on. Just a FYI, because that doesn't sound like YOUR problem. New shoes fix your's for a short time.
 
Do they keep turning the drums EVERY time? It could be that the drums are out of spec and need to be replaced, and the heat build-up keeps warping them. Are they even measuring them?!?!
 
I would just get new drums, sounds like yours are warped. You can turn warped drums so that they are round on the inside, But they will still be warped outside. Heat them up and they will just warp some more.
 
I'm thinkin' you've got a dragging brake problem. Heat builds up, warps the drum, pulses the brakes. I had the pulsing, sometimes almost banging/thumping/grabbing deal with my '92. Bought good, expensive drums, haven't had the problem for years. As the India and China crap flows through the supply chain, it's getting harder to find good stuff.
Also, you've got a stick shift, and probably use the e/parking brake. Make sure the cables are letting go, not dragging the brakes. As suggested, have someone cycle the brakes while you observe them-make sure they expand and contract fully (just push gently on the pedal-don't dislodge the shoes). I've seen ill-fitting spring kits, had the adjuster cable pivot become slightly dislodged, you name it.
You said the drums have been cut. Try to take them to a different machine shop, have 'em re-trued, or at least checked for maximum cut and roundness, see if they're out again.
See why discs are so popular! I'm itchin' to try the conversion kit from Summit ....

http://www.summitracing.com/search/...EEP/Part-Type/Disc-Brake-Kits/?keyword=brakes
 
heyhar said:
I'm thinkin' you've got a dragging brake problem. Heat builds up, warps the drum, pulses the brakes. I had the pulsing, sometimes almost banging/thumping/grabbing deal with my '92. Bought good, expensive drums, haven't had the problem for years. As the India and China crap flows through the supply chain, it's getting harder to find good stuff.
Also, you've got a stick shift, and probably use the e/parking brake. Make sure the cables are letting go, not dragging the brakes. As suggested, have someone cycle the brakes while you observe them-make sure they expand and contract fully (just push gently on the pedal-don't dislodge the shoes). I've seen ill-fitting spring kits, had the adjuster cable pivot become slightly dislodged, you name it.
You said the drums have been cut. Try to take them to a different machine shop, have 'em re-trued, or at least checked for maximum cut and roundness, see if they're out again.
See why discs are so popular! I'm itchin' to try the conversion kit from Summit ....

http://www.summitracing.com/search/...EEP/Part-Type/Disc-Brake-Kits/?keyword=brakes
Click to expand...

For about half of that, you can do a KJ disc brake conversion (if you have the 8.25 rear end) with mostly new parts!!

http://www.naxja.org/forum/showthread.php?t=977809
 
Yeah, but they're a little tough to find around here. We live minutes away from Harry's U Pull It, in my almost 40 years of 'junkin' the best yard I've come across, (a great source of XJ parts) and there's only been one Libby, and it had drum rears. I'm sure I could go next door to Kress, their real parts house, but they charge retail, and if ya pay retail, why not go new.
The problem I have with the Summit deal, is why the difference in price? I've studied the descriptions and the pictures, and cannot find a $300 reason for the difference in price.
 
ZJ brakes are the same thing, with a little grinding required. Heck 8.8 discs are almost the same, only a couple part numbers off. Probably could be made to work
 
heyhar said:
Yeah, but they're a little tough to find around here. We live minutes away from Harry's U Pull It, in my almost 40 years of 'junkin' the best yard I've come across, (a great source of XJ parts) and there's only been one Libby, and it had drum rears. I'm sure I could go next door to Kress, their real parts house, but they charge retail, and if ya pay retail, why not go new.
The problem I have with the Summit deal, is why the difference in price? I've studied the descriptions and the pictures, and cannot find a $300 reason for the difference in price.
Click to expand...

The difference is one is for if you have a ford rear end...see description and look closely!


http://www.summitracing.com/parts/TMI-004354400/
 
You must log in or register to reply here.

Similar threads

X
My brakes are crap
Replies
12
Views
3K
xjklmnop69
X
B
Dash brake light on after replacing rear brakes
Replies
1
Views
1K
RCP Phx
R
W
No Spark
Replies
6
Views
1K
Runnin'OnEmpty
R
N
2000 XJ, high miles, lots of new parts, still have vibration
Replies
10
Views
1K
N8N_99xj
N
G
Two mystery (to me) issues
Replies
2
Views
929
Rob Mayercik
R
Back
Top