Brake Problems-- Stuck Caliper Pistons? (1 Viewer)

[sjpitts]

My daughter and SIL have a new-to-them 99 100 series-- one that I found for them down here in AZ. They were out driving around Utah (Hobble Creek Canyon to be precise) and started to hear some noises coming from the driver's side front brake. So I am now trying to help them out from 600 miles away.

So he pulled the driver's side front wheel and took some pictures. The pictures show that there is some obvious scoring on the outer face of the rotor. But the pads look very new. Or at least not very worn. And certainly not worn enough to cause damage.

But it does look like the caliper is pushing on the pads in a way that is unbalanced. See the photo below with my red scratch marks. To me that looks like maybe the outer pistons are stuck. But that does not really explain the wear on the rotors. And it does not explain the noise.

All my land cruiser experience is with 80 series, so I am a little out of my comfort zone.

So does anyone have a better idea as to what might be going on here?

My SIL is currently at Harbor Freight buying some jack stands so he can tackle this with more safety.

Edit-- first picture shows this awesome 100 series the day I got it in AZ. I was very happy to find it for them.

Thanks

Jared

 

[3_puppies]

check the shiny part on the rotor, looking at the shot of the rotor from above, the left side has a shiny rub all around it, right next to the pad, between the left pad and the vents in the center of the rotor, maybe only the first third of the rotor thickness
something is rubbing there

 

[sjpitts]

check the shiny part on the rotor, looking at the shot of the rotor from above, the left side has a shiny rub all around it, right next to the pad, between the left pad and the vents in the center of the rotor, maybe only the first third of the rotor thickness
something is rubbing there

You mean this shiny part? I was wondering about that. I don't know what could cause that.

 

[3_puppies]

You mean this shiny part? I was wondering about that. I don't know what could cause that.

View attachment 3441121

yes that is what I was talking about, it shouldn't be there.
pull the caliper off and see if any of it was rubbing, or rock maybe?
caliper bolts loose?

 

[Malleus]

Stuck sliding pins. Common problem. Some kits have them, some don't. OEM doesn't; you have to buy them separately.

They don't come with the shims, either.

 

[sjpitts]

Stuck sliding pins. Common problem. Some kits have them, some don't. OEM doesn't; you have to buy them separately.

They don't come with the shims, either.

Are you saying we should buy some new pins and install them? I told my SIL to pick up some grease with the idea that they might need to be greased.

Jared

PS: I just noticed that the clip on the bottom pin was not properly clipped into the pads.

 

[RyanGriffith]

SIL here, here are some update pictures and videos. It seems like there is a bearing failure and the tolerance between the rotor and caliper is way off, causing the rotor to rub directly into the caliper.

 

[sjpitts]

Video-- another try


So I hope you can see that video. It is a link to google drive. The video shows that there is all kinds of play in the rotor--the rotor can move so much it clanks against the caliper. Seems a little nuts.

 

[medtro]

Do you have tools to repack the bearings? Check the caliper bolts too while you are in there.

 

[sjpitts]

Do you have tools to repack the bearings? Check the caliper bolts too while you are in there.

I do. But in Arizona. We may have to see if I can bring them as carry-on on a flight to Utah

 

[sjpitts]

My SIL checked the receipts from the previous owner. A full brake job with new bearings was done July 2022-- 14 months ago-- and less than 12k miles ago. So just slightly out of their stated warranty. And they are in Arizona so it probably does not matter.

 

[hoser]

Your hub might be simply loose. Take apart the front hub and tighten the nut. See FSM for specifics.

 

[Malleus]

Are you saying we should buy some new pins and install them? I told my SIL to pick up some grease with the idea that they might need to be greased.

Jared

PS: I just noticed that the clip on the bottom pin was not properly clipped into the pads.

Yes, replace the pins. When they get dry, they rust quickly and stick. Cleaning them is only a stopgap solution.

 

[Malleus]

SIL here, here are some update pictures and videos. It seems like there is a bearing failure and the tolerance between the rotor and caliper is way off, causing the rotor to rub directly into the caliper.

View attachment 3441259

View attachment 3441260

View attachment 3441261

View attachment 3441262

View attachment 3441263

You may have a bearing problem; the easiest way to check is to mount the tires, lift one off the ground and grab it at the 3 and 9 o'clock positions and see if you can move the edges in and out. This will be easy if the bearings have lost preload.

What you have pictured could easily have been caused by stuck sliding pins. I've seen this far more often than failed bearings.

 

[hoser]

Which sliding pins are you referring to? Front brakes have a fixed caliper.

 

[Malleus]

The ones I noted in Post #5. It's been my experience that the pads get stuck on these pins. Not as bad a problem as the 80 series floating calipers, but still a failure point.

 

[hoser]

Those pins just retain and guide the brake pads. The noise and interference is present with the brake pads and pins completely removed (see video).

The receipt shows the front inner bearing were replaced. My guess is the installer did not fully seat the bearing and the hub loosened after some driving. The bearings could be still good. Hub needs to be properly torqued down.

 

[sjpitts]

Thanks everyone for their advice. I think @hoser is right about the bearings. There is just no way the rotor should move like that (see the video). They were either not preloaded properly, not locked into place properly, or both. And I think @Malleus is probably right about the pins--they may be binding up and they are easy to replace.

So it seems like these are the options:

1) just properly tighten down and preload the bearings, and lock everything down with the locknuts. And maybe new pins to be safe.

2) Remove the rotor, regrease the bearings, then do 1)

3) Buy a new rotor, new bearings, new seals, install and then do 1). And then install new pads.

OR

4) Buy a new rotor, new bearings, new seals, install and then do 1). And then install new pads AND a new caliper (it does look like there may be a goove in the caliper).

Which one should we do?

Thanks again

 

[Malleus]

You'll need new seals in any event, but replacing the bearings may not be necessary, depending on their condition. Same for the rotor; it can be turned on the truck.

 

[sjpitts]

You'll need new seals in any event, but replacing the bearings may not be necessary, depending on their condition. Same for the rotor; it can be turned on the truck.

We will need new seals if we remove the rotor and remove and repack the bearings.

But not if we just tightened down the axle/bearing nuts to properly preload without removing rotor-- so it seems like you are saying we definitely should remove the rotor, repack the bearings at a minimum, right?

And I did some searching, and found this thread. When this guy's locknuts came loose it damaged the threads on his spindle. Let's hope that is not the case here.