rear brakes getting hot

[KB084RUNNER]

The pump is an accumulator pump not a proportioning valve, from the SM:

BRAKE FLUID (W/VSC)(From August, 2004)
BLEEDING
NOTICE:
Wash off brake fluid immediately if it comes into contact with a painted surface.
If the brake pedal is depressed with the reservoir cap removed, then brake fluid will spatter.
HINT:
If any work is done on the brake system or if air in the brake lines is suspected, bleed the air from the
system.
When bleeding, keep the amount of the fluid between the Min. and Max. lines on the reservoir.
1. FILL RESERVOIR WITH BRAKE FLUID
Fluid: SAE J1703 or FMVSS NO. 116 DOT3
2. BLEED BRAKE BOOSTER W/ACCUMULATOR PUMP ASSY
HINT:
Perform this step only if the brake booster w/ accumulator pump assy is removed and/or installed.
(a) Turn the ignition switch off, depress the brake pedal 20 times or more, and release the pressure from
the accumulator.
(b) Fully depress the brake pedal 10 times.
(c) Turn the ignition switch to the ON position and start the brake booster pump.
(d) Make sure the pump operates for 8 to 14 seconds.
If the pump does not operate as specified, repeat steps (a) to (c) and recheck the operating time.
3. BLEED BRAKE LINE
(a) Front brake line
(1) Turn the ignition switch to the ON position and wait
until the pump motor has stopped.
(2) Connect the vinyl tube to the brake caliper.
(3) Depress the brake pedal several times, then loosen
the bleeder plug with the pedal held down.
(4) At the point when the fluid stops coming out, tighten
the bleeder plug, then release the brake pedal.
Torque: 11 NVm (112 kgfVcm, 8 ftVlbf)
(5) Repeat (3) and (4) until all the air in the fluid has
been bled out.
(6) Repeat the above procedures to bleed the other
brake line.
(b) Rear brake line
(1) Turn the ignition switch to the ON position and depress
the brake pedal.
(2) Connect the vinyl tube to the brake caliper.
(3) Loosen the bleeder plug and release air.
HINT:
Brake fluid is sent through the pump, so keep the brake pedal
depressed until the air is completely bled out.

 

[blackoutt]

Bumping this ancient thread to get a little reassurance on why rear pads would wear faster than fronts? Pads and rotors replaced 50k miles ago with power stop kit from rock auto same compound front and rear, plus new OEM front calipers to replace sticky pistons. Rear caliper pistons and slides moved free so I left them. Fast forward to now and rear brake pads are gone, fronts still have lots of life?!?!? I did originally notice the rears got hot after I first changed them but no smoke so I left them. Checking all pistons today they still all appear to not be sticking, neither pistons nor slides. Does atrac and mud eat rear pads? I do offroad a little then highway trips hope while muddy.

 

[Runn4est]

Bumping this ancient thread to get a little reassurance on why rear pads would wear faster than fronts? Pads and rotors replaced 50k miles ago with power stop kit from rock auto same compound front and rear, plus new OEM front calipers to replace sticky pistons. Rear caliper pistons and slides moved free so I left them. Fast forward to now and rear brake pads are gone, fronts still have lots of life?!?!? I did originally notice the rears got hot after I first changed them but no smoke so I left them. Checking all pistons today they still all appear to not be sticking, neither pistons nor slides. Does atrac and mud eat rear pads? I do offroad a little then highway trips hope while muddy.

Can't say I have an answer, but I just noticed a rainbow rear rotor last weekend. The caliper didn't "seem" sticky either and the slide pins were in perfect shape.

I've had a new set of OEM 5th gen rears waiting for this to happen. Got Wagner Rotors and akebono pads waiting to be installed either this weekend or the next. I'll see if the heat drops and my MPG increases a little.

 

[blackoutt]

Hm 5th gen rear caliper swap is a possibility if that helps. Front I still have another set of new calipers "in stock" lol

 

[TechWrench]

Just a thought, check how the pads fit into the mounting slots in the frame. Over time, rust can build up under the small spring clips that the tabs of the pads ride on. This can cause the pads to not retract properly when the brakes are released. One way to tell if this is a problem is how hard is it to insert the new pads into the frame. If all is good, they should go into place with very little effort. If they are hard to get into place, then this is probably your problem. If this seems to be the problem, then remove the spring clips, and using the edge of a flat file, clean all the rust scale from the notches the clips sit in. I usually coat the area lightly with never-seize before re-installing the clips. If the rust is properly removed, the pads should fit into the slots with very little pressure, and be able to move back and forth easily. I have seen this problem for years, on many different vehicles with the one piston type caliper that Toyota uses on the rear wheels.

 

[blackoutt]

Good thought, I just threw new clips in with the new rear pads this weekend so I didn't even check. I do lightly lube the ends of the pads where they should slide on the clips. I did find one caliper pin pretty corroded, and the other three weren't very lubed anymore. Adding that to my tire rotation schedule now to keep them happy. New pads and hardware = no hot rear brakes for me after a long bedding and test drive.

 

[keakar]

with the wheels off the ground, can you detect any drag from the brakes? if so crack the bleeder and see if it releases.

you could have a bad brake line acting as a partial check valve not fully releasing the brakes. might also be whatever controls rear brakes through the ABS system making the rears do all the work. and dont overlook bleeding the fronts, because if they arent grabbing enough, the rears will take over

 

[AV8eer]

Hot rear brakes...

Reading the thread, one thought...if both rear brakes are getting too hot, it’s worth checking to verify that the front brakes are doing their share of the load.

In my case, left rear is overheating. I just installed a backup camera. I had the dash disassembled to do so, but I looked and looked and cannot see any way that I could have initiated this w the camera install.

Any thoughts?

Parking brake appears to go on and off as designed.

I’m stumped...

CONCLUSION: In the end, it was just a sticking caliper. The fact that it happened after backup camera install was just coincidence. The cable to the parking brake does have an adjustment screw in the center console, which was subject to my shop vac nozzle; ultimately, it just proved to be bad timing that sent me down a rabbit hole on what should have been a quick diagnosis and repair.

 

[cooper30]

Just throwing another thought out there...

I've had a couple vehicles over the years that had bad brake hoses which caused the calipers to stick. My current plow truck has this problem (but it is a yard truck, so idc).

The hoses will either collapse and not let fluid back through, or it deteriorates internally, a piece breaks off, and lodges in there with same result.

Crack the bleeder to see if the fluid is under pressure (it will squirt out).