sicma99ot

put on a 4.5" lift a couple months ago. while putting on the lift, i put in a lower mileage 8.25 rear end to replace my high mileage one. i used all the drum hardware from the old rear end. i was getting some vibes, so i swapped the old rear end and brake hardware back in thinking it was the new axle. turned out to be pinon angle. so i fixed that problem.


few weeks go by and hit the brakes pretty hard stopping short at a light and the drums lock up. not the front. so i jack up the rear end and find the brakes dragging. i adjusted them down. then the peddle felt soft. so i beld the brakes. still soft. another couple weeks go by and the peddle gradually gets stiffer and i can feel the drums locking up again. i jacked up the rear end again, pulled the tires and drums and found my adjusters were pretty wore. so i replace all the hardware and shoes. everything except the cylinders. they arent that old and still expand and compress. so i kept them. adjusted them till they barely dragged and then backed them down a couple turns. peddles still soft. bled the brakes 4 more times. still soft. i adjusted the brakes to where they barley drag. peddles firmer, stops better/faster, but too much pressure and they lock up. adjusted drums back down. peddles soft but dont lock up. couple weeks go by and now the drums are locking up again, but dont drag.


BULLET POINTS

• swapped axle and old drum hardware
• thought new axle was bad so swapped the old axle back in, with old brake hardware
• brakes lock up at a light
• adjusted down the drums
• peddle soft
• beld system
• peddle still soft
• couple weeks go by, peddle stiffer, drums lock up at hard stops
• replaced entire drum hardware and shoes, minus cylinders
• peddles still soft
• bled 4 times, still soft
• adjusted drums tighter
• firmer peddle, stops better/faster, but drums lock up under hard braking
• adjusted back down, soft peddle
• couple weeks go by and rear brakes lock up under hard braking
• front brakes never lock.
• about to say F it and take it to a shop.

its either the peddle is so soft it takes alot to stop it
or the peddle is firm and stops quickly but the drums lock up.

suggestions?


ninja edit: 98 4.0 auto, 4x4 swapped, 8.25 D30HP, RE4.5 SF 32 STT


im trying to get my heep back up from the 10-12mpg its getting right now (14mpg before lift and tires), and this is just the cherry on top. so i dont want to go spending money at a shop but im about to pull out my hair.

cruiser54

Do this:

https://www.cherokeeforum.com/f51/re...-8-25-a-57807/

sicma99ot

^its on my list. Have other thing I need to do first.

btw I have extended front and rear lines that came with my lift. And dont have my parking brake cables hooked up. I cut the old ones and the new passenger side was too short. In the 5 years ive owned my jeep, ive never used it. So I didnt bother hooking them up. Didnt think they were needed for the brakes to function.

But it feels like there is air in the lines. Or the back is getting more pressure than the front. But ive bled them like 5 times and theres no air in the system.

when I pump the peddle with motor off it gets stiff and doesn't sink. So the boosters working.

PocketsEmpty

Might be an issue with your master cylinder.

sicma99ot

Why do you suggest MC?

PocketsEmpty

I think a symptom of a bad MC is soft pedal / pedal going to the floor even after bleeding & with full fluid. But you mentioned it will lock up also. Is there any pattern to it?

sicma99ot

The peddle is soft when the drums are adjusted down but is slow to stop

when adjusted tighter, the peddle is firmer but drums lock when a too much pressure is applied.

I was able to get it to a liveable balance where the peddle was alittle soft and drums wouldnt lock but stopped decently. I would slam on the brakes every now and then to check if they would lock. after about 2 weeks I noticed the rears would grab harder than the front. When I pulled the drums. The adjusters werent where I left them.

if adjusted down and left, over about 2 weeks, they self adjust tighter until they lock

I dont leak fluid and peddle doesnt go to the floor.

sicma99ot

No pattern to the peddle.

freegdr

Adjusters on backwards ...?

sicma99ot

I dont think so. If they were backwards the star wheel wouldnt catch on the latch.

freegdr

Are bigger shoes on rear smallers on front ? Which drums did you use ?

freegdr

This would be drivers side yours look same .

Rogue4x4

Have you checked your prop valve? A bad prop valve would cause the rears to lock up....

sicma99ot

I think its the bigger (friction) pad goes toward the rear.

sicma99ot

Ah, prop valve. Thats a good suggestion. But what would cause it to suddenly go bad? The brakes were fine till I swapped axle. Maybe when I drained the fluid it got clogged? But I get good pressure when I bleed them.