I just took possession of a 2001 Jeep Cherokee. It has some problems including the brakes. The recent owner (a friend) said the brakes are not that old and were reworked a short time ago. Driving it home I noticed that the pedal is good and firm, the front brakes work as expected, and the rear brakes lock-up easily. They lock-up too easily and skid with medium brake pedal pressure. I think it would be dangerous in wet or snowy weather because it is so easy to get them to skid.
Any ideas on the problem?
You don’t tell us the year, number of miles on it or even if it has rear drums or discs. could be lots of things and I lost my magic 8 ball/
Pull all the wheels and inspect. Check the rears for fluid or oil contamination. Check the front for worn steering knuckles not allowing the pads to slide properly.
Check the condition of the rubber brake hoses near the wheels. They may be collapsing.
Does this Jeep have rear brake drums?
If so, I believe you need to concentrate on them.
It’s possible the rear shoes are contaminated
However, I think it’s more likely your drums are out of round and need to be machined and/or replaced
While you’re in there, make sure your axle seals and wheel cylinders aren’t leaking
These Jeeps do use drums in the rear, and I agree that they need a good look-see. Shoes are generally “self energizing”, and if everything isn’t in proper shape including the articulating linkage joints and the return springs they can lock up too readily. The springs are dirt-cheap, and at this age with this symptom I’d replace them while I was in there. Note that any black crud on the brake cylinders means a seal beginning the leak. It may on may not be a factor in your problem, but if you see any you definitely want to address it with a new cylinder.
Don’t forget too that these vehicles also have proportioning valves the function of which is to balance the front and rear break hydraulic pressures. Yours might be messed up.
A tip of the hat to your for recognizing this as a potentially dangerous problem. I doubt if 99% of Jeep owners would be that smart.
Hi guys, thanks for the input here. I will check today if they are drums. I am led to believe that they are. Given that, I was suspecting the proportioning valve and/or master cylinder, both of which I have very limited experience. Neither of which seem like fun tasks to replace.
I will have to take them apart this week and check the basics first. Things like the linkages, springs, hoses, drums, etc.
How can you tell it is the proportioning valve? Does everything else pass inspection and through a process of elimination make it the valve?
@@ oldtimer 11: I lost my Magic 8 Ball too! Reading through the original post, I am laughing at myself realizing I left out critical info that I usually am reprimanding others for!
It’s not the master cylinder, probably not the proportioning valve. Check everything noted above, if you’re not acquainted with brakes have a pro do it. It shouldn’t be too expensive to fix but it’s VERY important you do it.
Your friend may not know what a good brake job is. He may have only inspected the brakes and missed some vital clues that there was a problem.
I’d suggest redoing all the brakes including new drums and rotors. Then you WILL know that everything is up to par.
But only redo the brakes if you know how, otherwise see a pro.
I meant the brake cylinder rather than the master cylinder. I feel comfortable is stating that the master cylinder (MC) can be eliminated as a possibility.
part throttle - how many brake jobs on drums have you done?
Follow up on the rear brake problem: Took the rear drums off and the cylinders leak on both sides, lots of crud came out of the drums, and the shoes are paper thin. I will replace everything and see what happens!
Sounds like a plan
This is what I would replace, if I were working on it
complete brake shoe hardware kit, including ALL springs, adjusters, nails, etc.
Clean the ledges on the backing plate and apply white lithium grease
On the new adjusters . . . take them apart first, and apply silicone grease to the threads. Make sure they turn smoothly
Do one side at a time, so that you’re not at a total loss, if you forget where something goes
Do a complete brake fluid flush after you’ve got everything hooked up and adjusted
Remove all tension from the parking brake cable
Perform the brake shoe base adjustment
Perform the parking brake cable adjustment
In that order
Might want to soak the parking brake cable threads in WD40 the night before. It’s probably not been touched in years
I did most of what db4690 said. It is great. New wheel cylinders, hardware, shoes, brake bleed, and cleaned up old drums. Used old adjusters after a good cleaning and dab of anti seize. Adjusted drums to a slight drag. Pedal is firm and brakes are solid. Can’t believe leaky cylinders caused the brakes to hook up too soon.
Friend was partly right, checked front brakes and they had new calipers, pads and rotors. Must have forgot the rears!!
Shocks/struts might be next.
Thanks to everyone here. Once again, a great help.
Glad to hear you go the brakes sorted out!
Can you please define “cleaned up old drums” . . . ?
Does that mean you had them machined on the brake lathe?
Or you literally cleaned them up with sandpaper or emery cloth?
I hate to sound like a smart ass . . . but you did the wrong thing with the adjusters. You should have put silicone grease on the adjuster threads . . . as I advised you . . . not antiseize
Antiseize is fine on the backing plate ledges, but not on the adjuster threads
But all in all, I think you did real good!
What are we-peoples nannies? Every one who does brakes had a first time, And most of us learned before the dual master cylinder days. I assume that I am speaking to functional human beings who can decide for themselves if they are capable of doing a brake job.
Texases, I have done lots of rear drums and I really didn’t like any of them!! Too many small parts and springs. Always seemed kind of Rube Goldberg-ish. I keep hoping I have done my last set but it seems they keep popping up! I really appreciate the cautious attitude of the people on this forum. Things can get out of control in a hurry and brakes are one of the last things people want to go wrong.
The drums had a ledge of crusty rust on them where the shoes do not contact the friction surface of the drum. I cleaned it off with a half round file. The rest of the friction surface looked OK, no heat damage and the brakes did not surge or have a pulsating brake pedal before I did the work so I figured they were not out-of-round.
Stinks about the anti-sieze, should have figured it was a bad idea. I wanted something that would lubricate the threads and not get ruined from heat.
“What are we-people nannies?”
If that’s directed at me, please say so
If you did mean me, please consider that I congratulated OP and mentioned that all in all, he did real good