need help for the pros for TJ front brakes that stick

I have a 2002 TJ with new pads in the front ( put on early summer). I
was driving to work this morning and the front brakes stayed on. I
could feel the resistance and noticed the smell, and the drag from the
front. Both front wheels were hot to touch. What causes both of them
to stay on? The jeep was in a garage overnight so they were not frozen.
I assume it must be the module that controls the braking, but if there
is anything I can check it would be a help.

sounds like sticking callipers and or warped rotors. The callipers can be
rebuilt but generally for the price you may as well replace them, if the
rotors are warped (and they would be warped bad if their the culprit)
replace them don't even bother with having them turned. I'm sure someone
else will have better suggestions or experience with this so I'll leave
confirmation to Bill, Doug and a few others, but these are your most likely
candidates.

Snow 93XJ


> wrote in message
oups.com...
>I have a 2002 TJ with new pads in the front ( put on early summer). I
> was driving to work this morning and the front brakes stayed on. I
> could feel the resistance and noticed the smell, and the drag from the
> front. Both front wheels were hot to touch. What causes both of them
> to stay on? The jeep was in a garage overnight so they were not frozen.
> I assume it must be the module that controls the braking, but if there
> is anything I can check it would be a help.
>

If you have anti lock brakes you might have some controller issues but
I'd be looking at corrosion on the caliper pins. The calipers are free
floating on some pins that attach the whole works to the steering
knuckle. If those bind up (snow and salt really do a number on them!),
the outside pad will not release properly. If you have chewed up a
rotor, buy a new one, don't have the old ones resurfaced. Prices on new
aftermarket ones have come down in recent years, probability of warpage
after turning has gone up, just not worth the hassle.

wrote:

> I have a 2002 TJ with new pads in the front ( put on early summer). I
> was driving to work this morning and the front brakes stayed on. I
> could feel the resistance and noticed the smell, and the drag from the
> front. Both front wheels were hot to touch. What causes both of them
> to stay on? The jeep was in a garage overnight so they were not frozen.
> I assume it must be the module that controls the braking, but if there
> is anything I can check it would be a help.
>

I do not think it is the caliper since the chances of both of the
siezing at the same time is strange. I do not have ABS. But they both
stuck on with equal pressure since the jeep did not pull completely to
1 side. Also I do not think it is the rotors either since again both
of them going at the same time is odd.
Is there a chip or module that controls both brakes. I think that this
is the cause. It really seams like what ever unit sends the braking to
the front is not working correctly.

That is strange. If it was one side.....

There is a combination valve that controls the front to rear wheel
pressures and the Master Cylinder. Those are the only two places both
wheels have in common.

It is unusual for the combination valve to fail.

I have seen masters fail so the front brakes won't release.

I would test it by opening the line fitting for the fronts right at the
master. If pressure squirts out and they release, the master has failed
internally. (I just crack them, if under pressure it will come out fast
first, then slow right down)

If not, then I would open it somewhere after the combination valve on
either side to look for the stored up pressure. If none there, then I
would go to the wheel caliper and open it. If that is the only place to
show built up line pressure, then that implies the rubber lines from the
wheels to the frame have internally collapsed. It does happen.

This only happens on one side at a time though usually unless someone
put the wrong fluid into the brake reservoir. If it got the wrong
fluid, both front hoses could have died.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

wrote:
>
> I have a 2002 TJ with new pads in the front ( put on early summer). I
> was driving to work this morning and the front brakes stayed on. I
> could feel the resistance and noticed the smell, and the drag from the
> front. Both front wheels were hot to touch. What causes both of them
> to stay on? The jeep was in a garage overnight so they were not frozen.
> I assume it must be the module that controls the braking, but if there
> is anything I can check it would be a help.

Mike:

How was your 5 day bush run?

Tom

"Mike Romain" > wrote in message
...
> That is strange. If it was one side.....
>
> There is a combination valve that controls the front to rear wheel
> pressures and the Master Cylinder. Those are the only two places both
> wheels have in common.

It does seem strange that both fronts would stick at the same time. To me,
that is an indication of some sort of hydraulic problem as Mike said.

I would check the caliper slides though to see that they are cleaned and
greased properly. If you do need new rotors, most auto parts stores (at
least in the Cleveland, Ohio area) have the wrong part numbers for the '02
TJ.

My '02 TJ was built on 07/2001 so it was a very early production '02 model.
It uses full cast rotors, whereas the '01's and earlier used a composite
rotor. The full cast is a much better rotor, and is more resistant to
warping.

The correct part numbers for a full-cast rotor for '02 TJ's a
Bendix: 145276
Wagner: BD125716
Raybestos: 76923
Aimco: 5396

Any of the above numbers will fit, but the '01 composite rotors are NOT
interchangeable and will not work.

Here is a great write-up for disk brake service if you decide to do the work
yourself.
http://www.stu-offroad.com/misc/frontbrakes-1.htm

Tom

"Mike Romain" > wrote in message
...
> That is strange. If it was one side.....
>
> There is a combination valve that controls the front to rear wheel
> pressures and the Master Cylinder. Those are the only two places both
> wheels have in common.
>
> It is unusual for the combination valve to fail.
>
> I have seen masters fail so the front brakes won't release.
>

On 4 Jan 2005 06:03:41 -0800, wrote:

>I have a 2002 TJ with new pads in the front ( put on early summer). I
>was driving to work this morning and the front brakes stayed on. I
>could feel the resistance and noticed the smell, and the drag from the
>front. Both front wheels were hot to touch. What causes both of them
>to stay on? The jeep was in a garage overnight so they were not frozen.
>I assume it must be the module that controls the braking, but if there
>is anything I can check it would be a help.


I've seen a mis-adjusted brake light switch cause this by not letting the
brake pedal to fully return. It's worth a check.


--

Dave in Columbus

I had a similar problem after I replaced the pads on my 99TJ. The
piston in the caliper on the drivers side starting sticking. Replaced
the caliper with a rebuilt one from Autozone, about $20 with exchange.
A couple of weeks after that, the piston in the caliper on the
passenger side started sticking. Replaced that caliper also. I have had
no further problems and that was about 8 months ago. Anyway, I think it
is very possible your problem could be the pistons sticking even though
they are both sticking at the same time. I think installing new pads
had something to do with it. Put the piston in a different operating
range due to the thickness of the new pad. I didn't take the calipers
apart, but there could have been a groove in the bore catching the
piston.
Hope this helps. Good luck,
Frank

The skating was good for the kids.....

I will put up a bit of a trip report as soon as I get the photos
together.

Mike

mabar wrote:
>
> Mike:
>
> How was your 5 day bush run?
>
> Tom
>
> "Mike Romain" > wrote in message
> ...
> > That is strange. If it was one side.....
> >
> > There is a combination valve that controls the front to rear wheel
> > pressures and the Master Cylinder. Those are the only two places both
> > wheels have in common.