99 limited

ok so I have been getting this annoying vibration that runs thru the entire truck when I apply the brakes and the truck slows from 25mph until it comes to a full stop. ill give you a brief run down on the truck. '99 Cherokee limited lifted 6.5" running 33x12.50x20" aggressive mud type tires all brand new front steering linkage all over the knuckle plus heavy duty trac bar relocated above the axle. all brand new rotors semi metallic pads and all new caliper pins and bushings all quality parts all installed and broken in properly. this problem was present before the steering mods and the replacement brake parts. it is to me without a doubt the front brakes because if I apply brakes and it vibrates then let off and apply e-brake problem goes away. now I understand the tires I have are not the best but I highly doubt its the tires causing my issue because like I said the vibration is not present when I apply e-brake. I understand the xj's don't have the largest brakes out there but I would think if it was under braked they would just fade and warp rotors. has anyone ever experienced this problem. I also noticed if you look up calipers on rock auto they have a phenolic piston type and a steel type is there a reason for this and does it make any difference. I feel it is something that I have not replaced or over looking. any help would be greatly appreciated

JPXJMOAB

Sounds like the rotors are warped. Are the calipers new? Sounds like the caliper may have been hung up and overheated the rotor

andrewmp6

When you did the lift did you do a sye or a t case drop ?Have you had a alignment since all the work has been done?

JPXJMOAB

^ that too. My ZJ would get vibes before I'd stop from 5-10 mph the interior would rattle from it. In that case it was the mud terrains that caused it

99 limited

Ok so I didn't install the lift I bought the truck well over a year ago but I went over it and it was all installed correctly. Only thing I did was replace all the stock steering and trac bar with over the knuckle setup and over the axle adjustable track bar. I rebuilt both driveshafts as well with all spicer parts and yes it does have a transfer case drop and being my case is a np242 they don't make a shaft for it so it has the hack and tap type and I checked it and all work done was good. As far as brakes go this problem occurred before I did the brakes and it's still there with all brand new parts. Calipers where not replaced and seem to be working properly. As far as the tires go I'm not ruling it out. They are not the greatest quality tire they are the federal couragia or something like that but why would it do it when I apply brakes then immediately get off them and apply e brake it's not present. This is why I think it's something I'm missing or did not replace. Alignment was done after steering was all replaced as well.

JPXJMOAB

First off if you have a hack n tap get rid of the t case drop, no need for it. Second if it's ONLY when you're pressing the brakes you have warped rotors. Replace the calipers and rotors and post back.

99 limited

Rotors and pads are brand new I just did them and first ride it's the same. Problem is the exact same problem with old brakes as is with new.

99 limited

it seems like brake chatter and it vibrates thru entire truck. shakes the mirrors and everything inside right thru the seats as well.

andrewmp6

I have had the cheaper rotors from napa act like they are warped straight out of the box.And not torquing the lug nuts twice could also cause a brake rotor to warp.The other things it could be is a hub or ball joint.

JPXJMOAB

For the THIRD time. Just because the rotors are new does not mean they're not warped. If you have a sticking caliper you can drive 1 mile and have a warped rotor. Do some checking over the vehicle, check torques, and for gods sake don't say "it's new, that's not my problem". You'd be surprised how many parts are bad right out of the box

md21722

Many of us on NAXJA suggested the rotors too...

aj2494

I don't believe it's the rotors at all. He specifically mentioned that it happened at less than 25 mph. If it was the rotors, he would have vibes under braking at all speeds. So you don't have this vibe at all off-brake?

99 limited

that's correct. I know what warped rotors feel like. I'm not getting a pulsing pedal either or is it pulling to one side like a bad caliper. when I did the brake job the pads where almost finished and if anyone that has done brakes before know you need to compress them in order to get them on with new pads and rotors. they compressed with easy no signs of a bad caliper hydraulic wise. I will repeat myself the problem has been there since I bought the truck a year ago. I looked at the brakes when I got the truck and everything looked good and I just figured someone had might have installed full metallic pads and that was causing the harsh braking. I figured I would leave it see if it got any better but never did. now I bought all new raybestos rotors the ones with the small cuts for ventilation and semi metallic Bendix pads. I felt I used quality parts for todays standards being everything is made in china anyway. the first test ride proved the same result which was 1000' when I first applied the brakes from a 35-40mph speed. I find it highly doubtful a frozen caliper I just compressed and installed warped the rotors. I then next day bought new caliper bolts and bushings installed them and still the same. in the meantime I also removed the front driveshaft and drove it the same issue while it was out replaced everything with spicer parts just as a maintence interval same problem. I'm going to do the rear brakes now in a few weeks as a service thing and see if this helps maybe the rears are not doing much and the fronts are doing all the work but I doubt it.

JPXJMOAB

Just because a caliper compresses does not mean it's good.....

99 limited

I think I'm going to remove the rear driveshaft and put the front axle on jackstands and run it in 4wheeldrive and have someone run it up and hit the brakes and see if I see anything obvious. I think if I had a bad caliper that was frozen it would pull hard to the side that's working. truck tracks perfectly straight when brakes are applied.