Re: '00 GJC uneven brake wear
 

Does the 00 use slide pins or do the pads just slide along two surfaces
like they do on the ZJ?

If the surface, I've caused rear brake squawk by not thoroughly
polishing that sliding surface before installing new pads. Luckily mine
was reasonably harmless and I was able to cure it by pulling the pads
and using a Dremel to polish the slide surfaces up, then hit them with
just a teeny amount [not called out in the fsm] of silicone grease.

Yours look like the caliper itself is not applying even pressure when
the brakes are applied....OR...the brakes might be dragging on the outer
surface to cause that wear pattern and what is causing that may be
keeping you from getting much of any rear braking at all.

Any chance you dinged the rubber seal over the piston in the caliper, or
maybe that piston is wedged just a bit off kilter?

As Doug notes, best to pull them and be prepared to either have them
turned or just replace the rotors after doing a really good check of the
caliper and piston to make sure nothing is jammed or not reseating
properly. I always use a big C clamp to retract the pistons with a
helper pulling the extra brake fluid from the reservoir.


DougW proclaimed:

> DorkyGrin wrote:
>
>>I've got a GJC Laredo 4.7 and the rear brakes are wearing unevenly. In
>>fact the outer pads look like they only contact about half the surface
>>of the rotor. The other half of the surface is rusty and somewhat
>>corroded. Both rear rotors look the same. It's hard for me to tell if
>>there is a braking 'efficiency' problem as I don't drive the Jeep
>>regularly. It feels OK when I drive it but I suppose it could be
>>better.
>>
>>Here is a picture of the right rear:
>>http://i16.tinypic.com/43wrsrl.jpg
>
>
> Hmm... Odd pattern, the one cut line almost looks like a rock
> has been caught by the pad or the pad material has gone. Most pads
> are glued nowdays but a rivet could leave that mark. I'd take
> the caliper off and have a closer look at the pad face.
>
> Either way that disc is going to have to be milled or replaced.
> A new pad won't seat on a surface like that. These days new hats
> are almost as easy to do as having the originals milled. That and
> depending on how deep that is you might not have enough thickness
> left. (do both sides at the same time)
>
>
>>I replaced the pads about a year ago. They still look newish, like the
>>rear brakes are hardly used at all.
>
>
> Rear brakes are only a minor part of braking. The fronts do most
> of the work. When you take it apart check the piston to make sure
> you didn't bend it when pushing it back in. I always use the old
> pad and a big C clamp to press the piston back in.
>
>
>>I can't remember if the Jeep has slide pins, if it does I would have
>>cleaned and greased them .
>
>
> They have slide pins. But usually if a caliper sticks it just
> wears out one pad real badly.
>
>
>>Any ideas on how to troubleshoot this issue?
>
>
> Take the caliper off and look (post some pics) and the folks here
> might be able to give you a better idea.
>
>
>>Is there some adjustment that must be made on the rear brakes when
>>replacing pads?
>
>
> Only for the internal parking brake shoes.
>

Re: '00 GJC uneven break wear
 

DougW proclaimed:

> DorkyGrin wrote:
>
>>Oops, wrong side. Here is the other one:
>>
>>http://i10.tinypic.com/30cown5.jpg
>
>
> hmm.
>
> I dunno. Were the discs like that when you put
> new pads on? Can't tell from the pics if there
> is something wrong with the setup. Generally there
> is only one way to put the caliper back on.
>
> At this point I'd be looking at new pads and hats
> for both sides.
>

That assembly sure looks like the one on the older ZJ where the pads
have tabs that just sorta slide along the edges of the caliper mounting
area. However, I can't think offhand how that area being cruddy [which
it is a bit from your photo] would cause BOTH sides to look so close to
wearing only on the outer edge of the rotor. I would think even if the
little springs that seat the shoe into the piston were not seated fully,
the first time you apply the brakes they would seat.

I think in addition to rotor turning and pads, you might want to get kit
for the calipers and rebuild them. SOMETIMES local brake shops might be
willing to take a quick look at it and let you know if it would be
better to let them do it or you can do it yourself.

Re: '00 GJC uneven break wear
 

DougW proclaimed:

> DorkyGrin wrote:
>
>>Oops, wrong side. Here is the other one:
>>
>>http://i10.tinypic.com/30cown5.jpg
>
>
> hmm.
>
> I dunno. Were the discs like that when you put
> new pads on? Can't tell from the pics if there
> is something wrong with the setup. Generally there
> is only one way to put the caliper back on.
>
> At this point I'd be looking at new pads and hats
> for both sides.
>

That assembly sure looks like the one on the older ZJ where the pads
have tabs that just sorta slide along the edges of the caliper mounting
area. However, I can't think offhand how that area being cruddy [which
it is a bit from your photo] would cause BOTH sides to look so close to
wearing only on the outer edge of the rotor. I would think even if the
little springs that seat the shoe into the piston were not seated fully,
the first time you apply the brakes they would seat.

I think in addition to rotor turning and pads, you might want to get kit
for the calipers and rebuild them. SOMETIMES local brake shops might be
willing to take a quick look at it and let you know if it would be
better to let them do it or you can do it yourself.

Re: '00 GJC uneven break wear
 

DougW proclaimed:

> DorkyGrin wrote:
>
>>Oops, wrong side. Here is the other one:
>>
>>http://i10.tinypic.com/30cown5.jpg
>
>
> hmm.
>
> I dunno. Were the discs like that when you put
> new pads on? Can't tell from the pics if there
> is something wrong with the setup. Generally there
> is only one way to put the caliper back on.
>
> At this point I'd be looking at new pads and hats
> for both sides.
>

That assembly sure looks like the one on the older ZJ where the pads
have tabs that just sorta slide along the edges of the caliper mounting
area. However, I can't think offhand how that area being cruddy [which
it is a bit from your photo] would cause BOTH sides to look so close to
wearing only on the outer edge of the rotor. I would think even if the
little springs that seat the shoe into the piston were not seated fully,
the first time you apply the brakes they would seat.

I think in addition to rotor turning and pads, you might want to get kit
for the calipers and rebuild them. SOMETIMES local brake shops might be
willing to take a quick look at it and let you know if it would be
better to let them do it or you can do it yourself.

Re: '00 GJC uneven break wear
 

Make sure the slide surfaces are not just smooth but are shiny bright
and clean. A very very thin layer of silicone or lithium heavy grease
might help but make darned sure you apply it with something so you dont
risk getting even the tiniest amount on the rotor or the shoes.

That one groove just inside the wear pattern bothers me, almost like
something is jammed where it shouldn't be.


DorkyGrin proclaimed:

> I'll tear into it this weekend and inspect. I will probably end up
> replacing the rotors and pads. I don't remember there being any issues
> when I put pads on last time. If there was, I would have just replaced
> the rotors, they don't cost much.
>
> Thanks for the replies!
>
> DG
>
> RoyJ wrote:
>
>>If there is uneven wear from inside to outside on any rotor, your slide
>>pins are not working properly. Clean, grease, replace as required. If
>>you live in the rust belt, just replace the pins. BTDT
>>
>>Some vehicles have parking brake integrated with the piston, you have to
>>screw the piston onto the parking brake actuator when you change pads. I
>>DON'T think this applies to yours but I only have Jeep parts lists up
>>to 1996. These older ones have the drum brake inside the rear caiper.
>>
>>DorkyGrin wrote:
>>
>>>I've got a GJC Laredo 4.7 and the rear brakes are wearing unevenly. In
>>>fact the outer pads look like they only contact about half the surface
>>>of the rotor. The other half of the surface is rusty and somewhat
>>>corroded. Both rear rotors look the same. It's hard for me to tell if
>>>there is a braking 'efficiency' problem as I don't drive the Jeep
>>>regularly. It feels OK when I drive it but I suppose it could be
>>>better.
>>>
>>>Here is a picture of the right rear: http://i16.tinypic.com/43wrsrl.jpg
>>>
>>>I replaced the pads about a year ago. They still look newish, like the
>>>rear brakes are hardly used at all.
>>>
>>>I can't remember if the Jeep has slide pins, if it does I would have
>>>cleaned and greased them .
>>>
>>>Any ideas on how to troubleshoot this issue?
>>>
>>>Is there some adjustment that must be made on the rear brakes when
>>>replacing pads?
>>>
>>>Thanks!
>>>
>
>

Re: '00 GJC uneven break wear
 

Make sure the slide surfaces are not just smooth but are shiny bright
and clean. A very very thin layer of silicone or lithium heavy grease
might help but make darned sure you apply it with something so you dont
risk getting even the tiniest amount on the rotor or the shoes.

That one groove just inside the wear pattern bothers me, almost like
something is jammed where it shouldn't be.


DorkyGrin proclaimed:

> I'll tear into it this weekend and inspect. I will probably end up
> replacing the rotors and pads. I don't remember there being any issues
> when I put pads on last time. If there was, I would have just replaced
> the rotors, they don't cost much.
>
> Thanks for the replies!
>
> DG
>
> RoyJ wrote:
>
>>If there is uneven wear from inside to outside on any rotor, your slide
>>pins are not working properly. Clean, grease, replace as required. If
>>you live in the rust belt, just replace the pins. BTDT
>>
>>Some vehicles have parking brake integrated with the piston, you have to
>>screw the piston onto the parking brake actuator when you change pads. I
>>DON'T think this applies to yours but I only have Jeep parts lists up
>>to 1996. These older ones have the drum brake inside the rear caiper.
>>
>>DorkyGrin wrote:
>>
>>>I've got a GJC Laredo 4.7 and the rear brakes are wearing unevenly. In
>>>fact the outer pads look like they only contact about half the surface
>>>of the rotor. The other half of the surface is rusty and somewhat
>>>corroded. Both rear rotors look the same. It's hard for me to tell if
>>>there is a braking 'efficiency' problem as I don't drive the Jeep
>>>regularly. It feels OK when I drive it but I suppose it could be
>>>better.
>>>
>>>Here is a picture of the right rear: http://i16.tinypic.com/43wrsrl.jpg
>>>
>>>I replaced the pads about a year ago. They still look newish, like the
>>>rear brakes are hardly used at all.
>>>
>>>I can't remember if the Jeep has slide pins, if it does I would have
>>>cleaned and greased them .
>>>
>>>Any ideas on how to troubleshoot this issue?
>>>
>>>Is there some adjustment that must be made on the rear brakes when
>>>replacing pads?
>>>
>>>Thanks!
>>>
>
>

Re: '00 GJC uneven break wear
 

Make sure the slide surfaces are not just smooth but are shiny bright
and clean. A very very thin layer of silicone or lithium heavy grease
might help but make darned sure you apply it with something so you dont
risk getting even the tiniest amount on the rotor or the shoes.

That one groove just inside the wear pattern bothers me, almost like
something is jammed where it shouldn't be.


DorkyGrin proclaimed:

> I'll tear into it this weekend and inspect. I will probably end up
> replacing the rotors and pads. I don't remember there being any issues
> when I put pads on last time. If there was, I would have just replaced
> the rotors, they don't cost much.
>
> Thanks for the replies!
>
> DG
>
> RoyJ wrote:
>
>>If there is uneven wear from inside to outside on any rotor, your slide
>>pins are not working properly. Clean, grease, replace as required. If
>>you live in the rust belt, just replace the pins. BTDT
>>
>>Some vehicles have parking brake integrated with the piston, you have to
>>screw the piston onto the parking brake actuator when you change pads. I
>>DON'T think this applies to yours but I only have Jeep parts lists up
>>to 1996. These older ones have the drum brake inside the rear caiper.
>>
>>DorkyGrin wrote:
>>
>>>I've got a GJC Laredo 4.7 and the rear brakes are wearing unevenly. In
>>>fact the outer pads look like they only contact about half the surface
>>>of the rotor. The other half of the surface is rusty and somewhat
>>>corroded. Both rear rotors look the same. It's hard for me to tell if
>>>there is a braking 'efficiency' problem as I don't drive the Jeep
>>>regularly. It feels OK when I drive it but I suppose it could be
>>>better.
>>>
>>>Here is a picture of the right rear: http://i16.tinypic.com/43wrsrl.jpg
>>>
>>>I replaced the pads about a year ago. They still look newish, like the
>>>rear brakes are hardly used at all.
>>>
>>>I can't remember if the Jeep has slide pins, if it does I would have
>>>cleaned and greased them .
>>>
>>>Any ideas on how to troubleshoot this issue?
>>>
>>>Is there some adjustment that must be made on the rear brakes when
>>>replacing pads?
>>>
>>>Thanks!
>>>
>
>

Re: '00 GJC uneven break wear
 

Lon wrote:
> Make sure the slide surfaces are not just smooth but are shiny bright
> and clean. A very very thin layer of silicone or lithium heavy grease
> might help but make darned sure you apply it with something so you
> dont risk getting even the tiniest amount on the rotor or the shoes.
>
> That one groove just inside the wear pattern bothers me, almost like
> something is jammed where it shouldn't be.

I'm almost wondering if they are the correct shoe. There is also
left and right pads, possibly on the wrong side? Thought they only
fit one way.

http://revbeergoggles.com/temp/front-93zj.jpg

That however isn't close to the rear discs on the 00. Don't have
one of those in the picture archive. But on these if they give
you the wrong pads, the pads may fit, but they won't be properly
centered. hmm.. come to think of it, if the pad is not riding
on the knuckle it could rotate or tweak the whole caliper
off to one side. ...also... if there were any shims stuck in
the old caliper (or broken off bits of shims) then the new pads
would also sit funny. The 93 originally had separate shims on the
front, but later pads incorporated them, so you don't need them
anymore.

Found this site handy.
http://www.allpar.com/fix/Brakes.html

--
DougW

Re: '00 GJC uneven break wear
 

Lon wrote:
> Make sure the slide surfaces are not just smooth but are shiny bright
> and clean. A very very thin layer of silicone or lithium heavy grease
> might help but make darned sure you apply it with something so you
> dont risk getting even the tiniest amount on the rotor or the shoes.
>
> That one groove just inside the wear pattern bothers me, almost like
> something is jammed where it shouldn't be.

I'm almost wondering if they are the correct shoe. There is also
left and right pads, possibly on the wrong side? Thought they only
fit one way.

http://revbeergoggles.com/temp/front-93zj.jpg

That however isn't close to the rear discs on the 00. Don't have
one of those in the picture archive. But on these if they give
you the wrong pads, the pads may fit, but they won't be properly
centered. hmm.. come to think of it, if the pad is not riding
on the knuckle it could rotate or tweak the whole caliper
off to one side. ...also... if there were any shims stuck in
the old caliper (or broken off bits of shims) then the new pads
would also sit funny. The 93 originally had separate shims on the
front, but later pads incorporated them, so you don't need them
anymore.

Found this site handy.
http://www.allpar.com/fix/Brakes.html

--
DougW

Re: '00 GJC uneven break wear
 

Lon wrote:
> Make sure the slide surfaces are not just smooth but are shiny bright
> and clean. A very very thin layer of silicone or lithium heavy grease
> might help but make darned sure you apply it with something so you
> dont risk getting even the tiniest amount on the rotor or the shoes.
>
> That one groove just inside the wear pattern bothers me, almost like
> something is jammed where it shouldn't be.

I'm almost wondering if they are the correct shoe. There is also
left and right pads, possibly on the wrong side? Thought they only
fit one way.

http://revbeergoggles.com/temp/front-93zj.jpg

That however isn't close to the rear discs on the 00. Don't have
one of those in the picture archive. But on these if they give
you the wrong pads, the pads may fit, but they won't be properly
centered. hmm.. come to think of it, if the pad is not riding
on the knuckle it could rotate or tweak the whole caliper
off to one side. ...also... if there were any shims stuck in
the old caliper (or broken off bits of shims) then the new pads
would also sit funny. The 93 originally had separate shims on the
front, but later pads incorporated them, so you don't need them
anymore.

Found this site handy.
http://www.allpar.com/fix/Brakes.html

--
DougW