Sticky brakes

[baby#yota]

Hello all, looking for some input on my situation. I have an 05 v6 SR5, with roughly a quarter mil on the clock. I’ve had the truck for over a year with ZERO problems except reoccurring brake problems and some maintenance etc. The truck is in great shape with no rust so I snagged it fast when I saw it on the market. However I’ve come to realize the 4th gens are known for sticking calipers. It got so bad last summer that you could smell the brakes if you had a window down. I replaced both rear calipers, rotors, pads etc and she was fine. I had one occurrence of heating up but I followed anther users recommendation to just sit and pump the brakes to remedy…and it worked. So here I am now pulling into work and I walk by my truck and see my caliper literally steaming. Very frustrating. The left rear has always been the problem, the RR was slightly problematic but I replaced both as a pair just to be safe. So I’m torn because I really don’t want to go and replace ANOTHER set of calipers just to buy myself another year. There is some other underlying problem not being addressed here, I’m thinking collapses brake line possibly?

The last clue for y’all is I’m running powerstop calipers, rotors etc. the previous owner put them on and when I did the replacement last summer I bought another set so the back would match the front. As far as I can tell from the castings is they are OEM just painted red. Aside from looking sporty I don’t believe there is any difference. So do I just say **** it and buy anther caliper, switch all of my gear to OEM, or invest in 5th gen hardware and do the conversion? Open to any other ideas as well.

 

[chris in ky]

I had the same problem on my '06. I ended up replacing all four calipers and no problems since. The fluid has to be thoroughly purged out of all four corners and the calipers MUST be bench bled.

 

[baby#yota]

I took a closer look yesterday and was able to compress the caliper easily. I cleaned and greased the slides etc. I had no change on the test drive but this morning it seems to not be sticking. The inconsistency is frustrating.

 

[Buckaroo]

I use Powerstop components on all my vehicles including my '05 T4R Limited. I would not just change out all the components but instead take the wheel off the one that was hot and see if that caliper is moving freely. If not, I would disassemble, clean and regrease if it is not damaged. When you compress the caliper, it is always good practice to open the bleeder first so that fluid is not forced from the caliper back into the system. Recommend use of Permatex Silicone Ceramic Extreme Brake Part Lubricant #80653 which is good for not only the metal parts but safe for rubber and plastic.

It could very well be the interior of the flexible hose running to the caliper is damaged trapping fluid and not allowing it to flow back to release the caliper. This can happen if folks clamp off these lines when removing calipers to keep brake fluid from dripping. Open the bleeder before you check the caliper to make sure that there is no residual pressure holding it. You might want to replace the hose on that wheel, particularly if the caliper is moving freely or if you had any residual pressure- about $68 list/$50 on line discount (Toyota part number: RH Rear - 90947-02D31, LH Rear - 90947-02D32).

Brake fluid should be flushed every two years or so - it picks up moisture over time and can cause internal corrosion. You need to bleed all the fluid out of he entire system, one wheel at a time until you have good, clean fluid. If you are going to be doing brake work, get yourself a Motive Power Bleeder or a Mityvac MV6830 if you have a compressor.

https://www.youtube.com/watch?v=uJ4gRAmNVnM

 

[Buckaroo]

I took a closer look yesterday and was able to compress the caliper easily. I cleaned and greased the slides etc. I had no change on the test drive but this morning it seems to not be sticking. The inconsistency is frustrating.

You posted this while I was typing. This does sound like the brake hose on that wheel is damaged internally and preventing back flow, perhaps intermittently. I would flush the system (if you haven't already done so) and replace that hose.

 

[MikeinNH67]

I'd also look into the short rubber hose that's attached to that caliper. Rubber hoses do fail by not letting low pressure fluid back through. Otherwise I'm pretty sure the rear brakes share all the same lines until you get to the T that is on the rear axle. BTW, don't assume the caliper is good just because it's new-ish. It's probably a rebuilt unit.

 

[baby#yota]

update: I had a brake line on my parts shelf for months so I decided to tear into it again yesterday. I installed new pads just in case a rust ridge on the piston was causing it to stick I figured pushing it in a bit with new pads might help. spoiler, it did not. I also installed a new flex line at that caliper and bled the system. Some improvement for about 20 minutes until I could smell it cooking again on the highway. I've decided I'm going to do the 5th gen brake upgrade on the rears. 5th Gen 4Runner Brakes Upgrade (for 4th Gen 4Runner)

Parts come in Friday and hopefully, this is the last time I have to mess with this truck's rear brakes. I will also schedule an appt with my local shop to do a fluid flush. I can bleed brakes fine but I would rather have a shop with access to a bidirectional scan tool do the flush and actuate the ABS module. I can do a lot in my garage but I do have limitations.

I will update soon, thank you for the info

 

[dasx86]

Bought my truck with 174k miles. 6 years later, I have 235k miles.

I have replaced the front calipers 3 or 4 times, and the rears once. So I'm averaging replacing the front calipers every 15-20k miles. It's ridiculous

Parts are cheap though. Good truck otherwise :shrug:

 

[Buckaroo]

Sorry you are still having the problem. You might do a visual on the hard brake lines going from the rear all the way to the front and make sure one of them is not bent or crimped.

 

[MikeinNH67]

You might do a visual on the hard brake lines going from the rear all the way to the front and make sure one of them is not bent or crimped.

I believe it's a shared line on the back so both sides would be affected.

 

[baby#yota]

Update:

Alright guys I just finished up replacing my calipers. The old one got so bad my whole truck was shaking even if I wasn’t in the brakes, completely warped and overheated. I went with 5th gen calipers, brackets and pads. I used new 4th gen rotors and had zero issues installing everything. I did some testing to see if the issue was in fact the calipers or lines, it ended to being just the calipers. For good measure I replaced the flex lines while I was in there but that may have been overkill. I have 17” rims and the new larger rear calipers fit perfectly. If anyone is interested check out the article I linked earlier or I can make a post with part numbers. Hopefully this is the last time I have to mess with there brakes!

I will update if this issue returns but from what I can see here on the forum the 5th gen upgrade is the only way to fix this permanently. I will upgrade the fronts eventually when they start seizing….hopefully not for awhile.