hello everyone

some of you might know me from my other thread about work done on my 98 jeep grand cherokee loredo 2wd.

i was going to just update to that thread but i think we've had enough of it and i really need some help here with this issue.

i had the front rotors and break pads replaced. upon driving the vehicle i get a knocking noise. here is a youtube link (not my vehicle) but its the same noise and a lot of details are the same, new rotors, new pads, etc

to make a long story short i think in the video it was the pads and i found other website saying the same thing but the mechanic that was hired would not here of it and said it was a warped rotor and if i get a replacement part he will fix it (i don't need his help on that).

so today i got around to working on this. the first step in the process of elimination (something he really should have done) was to take it apart and do it all again.

when i was taking it apart it appeared the pad on the drivers side was not quite right. so anyways i took everything apart and put everything back together.

test drove, noise still there, it was not there before the new rotors and pads.

so next step was to put on the old pads and test drive, the noise was gone even at higher speeds it just was not there.

so i took the new pads back and got replacements and then preceded to put them back on. test drive, noise is back.

i could see one set of defect pads but two does not seem normal but i can not figure this out. the old pads probably have a few months left on them but that would only delay the issue.

any idea what could be the issue?


i can't see what difference there is between the old pads and new ones that would make this an issue.

any help would be appreciated.

ryan

 

oh wow i hope this link is ok

i didn't know it would show up like that

 

oh and i will say this time around the knocking is not as loud as before its there but not as loud

 

is there any pulsation in the pedal? were the new pads you just got the same brand and quality, id try a different brand and maybe move up to a higher quality.

 

same brand and quality as the pads that was on the vehicle since 2008

duralast gold series

replaced under the lifetime warranty

 

id buy a a set of the cheapest ones you can get and try them just to eliminate any chance of a bad batch of pads. cant offer much more than that but since it goes away(noise) with the old pads that why i suggested it

 

ok

i missed a quesiton erlier

no there is no pulsation when using the breaks only that noise.

ok so i went to the auto store today and got antoher set of pads, different brand all together.

the guy at the counter also complained about the pads saying some times you need to file the rough edges and such so i decided to try that first.

so i did that and test drove, still makes the noise

so i put on the new cheap ones and test drove still makes the noise.

could it be that the rotor just needs to break in first?

as i said i can put on the old pads and the noise is gone but if there needs to be a break in period then that would also i think be good too since those pads are probalby 85% gone. maybe its a combination of new rotor and new pads.

i've done more on and off of the breaks more in the last two days than all the break jobs i've done previously.

i've tried them with grease/lube and without don't seem to make any difference.

the pads feel like they are on there good everything looks good to me.

i changed pads on this jeep on 2008 and didn't have any issues but i didn't do the rotors though.

any ideas would be great or should i just keep driving it and see if after a while the noise goes away.

i think comments on the video states the shop changed the new pads and did something to the rotor too.

 

Did the calipers compress ok? They didn't fight you? I just did my rotors and pads and I had a squeak for and 50-75 miles but then it went away. There is a break in period so keep that in mind. I also changed my calipers because mine wasn't releasing properly and it was extremely hard to compress the piston

 

no they seemed to go alright.

one side harder than the other to do but i think that was becasue of the slight angle of the driveway and it made me sit/work at a different angle

the passenger side when on quickly every time but the drivers side required most of the time a screw driver or something to get the brakes/caliper off

i just find it hard to think its something when i put on the old pads it works without the noise, but woudl a bad or caliper going bad be like that, old pads are worn enough its not a big deal for it but add a new rotor and new pads there's a problem?

i'd say the last pads i had on there went over 100 miles before i was able to get to check them out again. i will say though the noise while still there is defiantly not as loud as it was in the beginning. the new pads has only has a few blocks of driving

 

calipers are $40 bucks each

then when i return the old ones i get $40 bucks back

so when its done each one is $20 bucks.

if i replace them should i replace both at the same time i would think so or should i just wait a bit.

 

I just replied to another thread regarding brakes and the little "extra" shims that come with high end pads. These little clips come with pads like Wagner Thermoquiet and are different thicknesses. They are to take up any slop between the pad back plate and where the pads ride on the hub/knuckle.

You might have some wear or just a manufacturing difference in the pad backing plate that is allowing extra movement and noise from the pads shifting on the hub/knuckle.

See this thread for a photo of the clips I am talking about.

https://www.cherokeeforum.com/f2/pro...h-work-177338/

You could also try comparing the size of the back plates on the new pads that make the noise and the old ones that do not.

 

the old pads and the new ones are the same size, i compared them already. same size, same brand same series (duralast gold series). the other cheap ones are not the same company but they are the same size.

the only difference in them is the size of the braking pad thats on them with the old ones being at the very end of their life.

 

I'm having the exact same problem. Replaced the pads, rotors, calipers and soft brake lines as the others seemed about at the end of their life. Now I have brakes that work, but the pads rub on the rotors and make them almost sing. It's so loud I can't even drive up to the shop to have them look at it. The pads were match up prior to the change, lubed, brakes bled....they work great but make that damn noise!

Any ideas? Did you ever figure yours out?

Thanks,
Dave

 

1) Does it make the same noise when braking in reverse?
2) Are both pad positioning springs present on each caliper?

I'm not familiar with GC calipers but if they're the same design as those found on XJs, there are two springs (usually chrome) on each caliper that many backyard mechanics consider redundant (and a PITA to re-install) so they just toss them. They aren't redundant, they prevent the pad backer plate from banging into the caliper cage under load.

 

This is the retaining spring I'm talking about...