I've seen the comments from folks talking about how the front calipers go bad with the lower inside piston freezing. So when I planned to do the brakes on all four wheels this past weekend I stopped by the local dealer to pick up a few pieces like the caliper pins and clips. Asked the parts guy about bad calipers. His response?

"Nah, they rarely go bad".

So yesterday when I pulled the front calipers to replace the rotors I found that not one but both calipers had a frozen lower inner piston. Tracking down rebuilt calipers for the truck was loads of fun on a Sunday.

Next time you get ready to do a front brake job find out which local parts store has the right casting of your particular caliper in stock. Especially at a good price. If they don't have them see if they can get some in stock on the day you do your brake job. Cause chances are you are gonna be driving there to get em.

Good info. I've seen posts here where people spend upwards of $1200 to get the calipers re-done. I just looked at an old receipt from the previous owner: $700 for 2 new calipers, rotors, and ceramic pads all around (front end only)

Toyota truck four-piston front calipers are notorious for this. That parts guy was talking out of his hole. It's always wise to play it safe and splurge for reman calipers when doing front brake jobs on Toyota 4WD trucks with four-piston calipers. The last time it cost me an extra 200 bucks overall but it's worth it. Toyota truck brakes are really strong when working 100 percent.

When I first read about 4th Generation Brake Pistons being frozen, I was fully awared but lagged. When I did an oil change & rotation at 50k, I noticed my front brakes were low, so replaced the pads & that's where I realized that my pistons were starting to freeze. The pin was started to get stuck too. Penetrating Grease helped relieve them.

So now...I always press in my pistons at every rotation.

What kind of penetrating grease did you use? Do you mean like a PB Blaster? Or am I stupid for asking? Something Napa should have in stock?

I like the preventative idea.

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I have PB Blaster at home, but used Penetrating Grease at friend's shop.

Both are the same thing, just different name/brand? *don't know*

Any Automotive shop will have Pentrating Grease, even Home Depot has it.

Does anyone make a high performance replacement caliper?

I was in the same spot. Auto Zone is handy since their open Sundays but I didn't have any luck with calipers. I ended up going to Napa. They had to order them but I got the right one the first time.

Would the PB or other penetrating oil harm the rubber boots?

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Just went through that this week too, of course it was the night before I was supposed to leave on a 1000 mile trip. Wife tells me that the steering is pulling to the right and shaking when stopping. I go for a five minute test drive and it's bad. Right front was seized and dragging and was hot. With no time to fix myself I was forced to drive it as is 30 minutes to the stealership, stopping every 5 minutes to cool it down. Brought a bucket of water and a fire extinguisher just in case!

Needless to say it needed a new right caliper and pads. Rotor was ok with a light resurfacing. But of course it got worse. While replacing the left side pads it was noted that the 2 lower pistons on that side were siezed as well. I was pissed since that one had already been replaced 1.5 years ago. Nearly $1k later I was on my way.

Only good thing is the huge difference it made. Without the dragging brakes I have power and pickup again and gained 7mpg!! Was averaging 13 driving at 50mph now getting nearly 20 driving 75mph on the road trip.

It's time for Toyota to step up and admit the problem. That's 5 calipers on 2 T4Rs in 3 years for me.

Reading about the notorious frozen caliper on the 4th Gen makes me wonder if I should give all four of mine a few squirts of PB Blaster as a preventative measure. Exactly where to spray?

Lets say the calipers are already frozen, would penetrating grease (PB Blaster) help now or are they totally done?

Adding to this, what do you look for to identify a frozen caliper, do you have to be pressing the brake pedal and watch to see if the piston moves or not or is it something you just move by hand? Does anyone have a picture of what to look at/for? I've never done a brake job before but I've read many threads with instructions so that I can do my own when the time comes.

Un bolt the caliper. remove pads, and put a small wrench across pistons, apply C clamp to wrench to backside of caliper, tighten, which will compress pistons back in. careful, slow with this, as fluid will go back up to Master Cylinder, you dont want to overflow there if possible.

compress til they are even on each side. that means they are not frozen. re install them with pads of course. start it up and reapply the brakes several times to push pistons back out, pads against disc. prior to reverse or fwd gears as you wont have much brakes to hold it back.

you are now freeze free.

Just went to change pads and rotors today... Guess what FROZEN on the driver front. Luckily advance has reman I just picked up - gonna be a project tomorrow... I bought the passenger side before even seeing if it's frozen or not as well.

I just don't have too much of a clue when it comes to bleeding the brakes.. Oh well, guess I'll be learning on the fly.

I shoulda just planned ahead to do the Tundra mod. Thought i'd be the lucky one..

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Well, I don't know if mine were frozen at 80k, but one pad was worn down 1/4" more on both sides than the other. I changed the calipers on the front, and all the rotors and pads. I REALLY wanted OEM pads, but the dealership tried to charge me $130 for the front pads alone. The next nearest dealer is 50mi away, and since I'm moving across the nation couldn't wait to order through partznet. So I ended up going with Wagner thermoquiets. I'm not a mechanic by any means, but I found this job really easy compared to how worried I was about it. Especially since I forgot my instructions at home. Thank God for my smart phone! I also saved $650, which is what the same dealer wanted to charge for labor alone. And no more shakes from the steering wheel when I brake!

happy I got this done.

Stanley, to bleed, start at the rear right, rear left, front right, front left for the order. Grab a bottle and put a little brake fluid in there. Then have someone turn the power on to the car but not the engine. Hook your tube up to the bleed nozzle and have the other end in the bottle with it in the brake fluid. Then crack the bleed screw open with a wrench about a quarter turn. Have your buddy pump the brakes until its solid fluid with no bubble of air. Move on to the next one. I kept getting a brake horn and warning light. I dunno on that one. But make sure you check the resevoir after every wheel to refill it to max.