[mack10]

Getting around to figuring this out...

While driving the truck has a slight tendency to track right, so this led to me to think alignment was off. Under hard brake it pulls quite a bit to the right. After reading the various similar problem threads I took a harder look at the brakes.

All tires inflated to 40PSI as per the tire specs.

Temp gun probably best troubleshooting tool for this, anyone else having this problem should take one on a test drive and do a few passes and record the results.

In doing the temp based tests, after driving for a couple miles, it didn't appear the left or right fronts had any significant difference maybe a couple degrees higher on left. Rears fine. Pulling the parking brake while driving slowed the truck evenly, no pull to either side.

What was suspect is the temp of the left side after heavy braking. It would be about 100 degrees C while the right about 50-75C. But pulling hard to right..

I pulled the right caliper today and did a full rebuild, greased sliders, bled the system, but problem persisted after a quick test drive. The caliper did have rust in the cylinders and it appeared that the outer pistons were not working well at all. After all that seems like I should have started with the left instead..

So does the extreme heat buildup of left side mean that some pressure is being applied, but not alot, causing a quick ramp up in the temp as the pads drag and the other side does the actual braking? Really hoping that is the case and I will be able to rebuild that one tomorrow. Seems logical but these problems really are multi-faceted...

Have new LBJs (OEM), UBJs, tie rod ends and sway bar end links, swaybar bushings about 20k miles ago so don't suspect those and the high heat of the left caliper rules those out. There is also no rattling, clunking or shaking of the steering wheel.

Any other thoughts on this one?

[JRZEE2000TR4LTD]

Originally Posted by mack10

Getting around to figuring this out...

While driving the truck has a slight tendency to track right, so this led to me to think alignment was off. Under hard brake it pulls quite a bit to the right. After reading the various similar problem threads I took a harder look at the brakes.

All tires inflated to 40PSI as per the tire specs.

Temp gun probably best troubleshooting tool for this, anyone else having this problem should take one on a test drive and do a few passes and record the results.

In doing the temp based tests, after driving for a couple miles, it didn't appear the left or right fronts had any significant difference maybe a couple degrees higher on left. Rears fine. Pulling the parking brake while driving slowed the truck evenly, no pull to either side.

What was suspect is the temp of the left side after heavy braking. It would be about 100 degrees C while the right about 50-75C. But pulling hard to right..

I pulled the right caliper today and did a full rebuild, greased sliders, bled the system, but problem persisted after a quick test drive. The caliper did have rust in the cylinders and it appeared that the outer pistons were not working well at all. After all that seems like I should have started with the left instead..

So does the extreme heat buildup of left side mean that some pressure is being applied, but not alot, causing a quick ramp up in the temp as the pads drag and the other side does the actual braking? Really hoping that is the case and I will be able to rebuild that one tomorrow. Seems logical but these problems really are multi-faceted...

Have new LBJs (OEM), UBJs, tie rod ends and sway bar end links, swaybar bushings about 20k miles ago so don't suspect those and the high heat of the left caliper rules those out. There is also no rattling, clunking or shaking of the steering wheel.

Any other thoughts on this one?

I've had 2 dragging calipers on my 1st truck. Put 199s on my second. Rebuilt both with OEM kits and pistons. Lightly honed the piston bores. The passenger side caliper started to drag. Took it apart and clean it all up. Started to drag again about 6 months later. Had enough and just replaced the caliper. I HATE working on thing twice, let alone 3x.

[mack10]

Forgot to mention.. the calipers, rotors and pads were new 20k miles ago as well.

Seems like the culprit is weak seals that allow moisture to sit and build rust which eventually fouls the bores. I didn't do the install, but I am seeing that the brakes need more than cursory attention if you want to avoid these headaches. Greasing the outer seals would help a bit as well as more regular maintenance/inspection. First I tried greasing the inner boot lightly as well but found it made getting the retaining ring on a hell of a lot harder, as it kept sliding off. Overall - PITA.

[JRZEE2000TR4LTD]

Originally Posted by mack10

Forgot to mention.. the calipers, rotors and pads were new 20k miles ago as well.

Seems like the culprit is weak seals that allow moisture to sit and build rust which eventually fouls the bores. I didn't do the install, but I am seeing that the brakes need more than cursory attention if you want to avoid these headaches. Greasing the outer seals would help a bit as well as more regular maintenance/inspection. First I tried greasing the inner boot lightly as well but found it made getting the retaining ring on a hell of a lot harder, as it kept sliding off. Overall - PITA.

Yes, same thing I saw. Tried the grease thing with the same result. I ended up painting right up to the edge. Same result 6 months later. We'll see how this caliper holds up.

[MaineRunna]

Your left front caliper is seized up, the right is doing all the work and the left is just kind of dragging. Get a Napa Eclipse caliper, they are powdercoated black. (it's still a Cardone caliper though)

[mack10]

Originally Posted by MaineRunna

Your left front caliper is seized up, the right is doing all the work and the left is just kind of dragging. Get a Napa Eclipse caliper, they are powdercoated black. (it's still a Cardone caliper though)

It definitely was, the sliders were rusted pretty badly. However the cylinders still worked after I removed the pads and threw in some plywood so they wouldn't pop out. Enough to crush the plywood after a couple pumps. Instead of taking it all apart I cleaned up the pins lubed everything and put it back together. Still have the same problem though so I'll probably get a set of the NAPA calipers. There's also quite a big difference in pad material left vs right, even if the caliper was working fine (now) would the difference in the pad thickness still cause this? I drove it around quite a bit and tried to bed in the left side but it didn't seem to improve... If I get new calipers I'll have to get pads anyway.

[JRZEE2000TR4LTD]

Originally Posted by mack10

It definitely was, the sliders were rusted pretty badly. However the cylinders still worked after I removed the pads and threw in some plywood so they wouldn't pop out. Enough to crush the plywood after a couple pumps. Instead of taking it all apart I cleaned up the pins lubed everything and put it back together. Still have the same problem though so I'll probably get a set of the NAPA calipers. There's also quite a big difference in pad material left vs right, even if the caliper was working fine (now) would the difference in the pad thickness still cause this? I drove it around quite a bit and tried to bed in the left side but it didn't seem to improve... If I get new calipers I'll have to get pads anyway.

The difference in pad thickness is a result of the caliper dragging. Those pin sliders really don't restrict anything. Not like my old Exploder. Get some calipers and pads and go from there and get out from underneath that truck. I'm sure you have better things to do.

[timmytimtim]

If you're thinking about replacing calipers, watch this guy's video which touches on 2 suggestions I'd have for you: YouTube

1) Commit to the Tundra brake upgrade, which gives you more brake pad surface area (Hard to find Specs, Info & Measurements on 231mm 13WL Tundra Calipers & Rotors - Toyota 4Runner Forum - Largest 4Runner Forum) - I have the calipers marked 13WL and can agree with everything on that linked thread. They are a direct bolt-in, and if you are looking to replace calipers and pads anyway, you could go ahead and make this replacement session an upgrade session with the addition of new rotors.

2) Rebuild your calipers. A few months ago I was having the same issue of one caliper not wanting to compress. The seals were shot, so they weren't doing their job of keeping dirt/grime out. Instead of replacing the calipers, I replaced all seals with what many call a "caliper rebuild kit." I've found them on dealership and Toyota parts sites called "overhaul kits" for front brakes.
I searched for 2000 Toyota 4Runner and its calling for Toyota part 04479-35040. I used 04479-0C020 for the 13WL Tundra brakes. Individual caliper pistons are available as well.

[MaineRunna]

Originally Posted by mack10

It definitely was, the sliders were rusted pretty badly. However the cylinders still worked after I removed the pads and threw in some plywood so they wouldn't pop out. Enough to crush the plywood after a couple pumps. Instead of taking it all apart I cleaned up the pins lubed everything and put it back together. Still have the same problem though so I'll probably get a set of the NAPA calipers. There's also quite a big difference in pad material left vs right, even if the caliper was working fine (now) would the difference in the pad thickness still cause this? I drove it around quite a bit and tried to bed in the left side but it didn't seem to improve... If I get new calipers I'll have to get pads anyway.

If you're running oversized tires, have added a lot of weight (bumpers, winch, etc) or tow a lot go for the Tundra brake upgrade. Just buy pads, rotors and the 13WL calipers for a 2005 Tundra 4X4. If you are stock, then the stock brakes will do.
I did mine using Wagner rotors & Cardone calipers from Pep Boys and pads from Toyota after putting my bigger tires on with new, much heavier 4XInnovations bumpers and realizing that the Runna didn't want to stop. Almost puts me through the windshield now, big difference, highly recommend!