Caliper Rebuild Problem, Rear Caliper Sc400

[lexus082]

I tried using up to 120 psi of air to get that piston out and I still can't get it out. Any suggestions?? I started with 40 psi and that didn't do anything. Then I tried with 90 and that got it to move, then I tried with 120 psi and that got it most of the way out. I tried turning it with pliers but no luck. First time rebuilding a brake caliper.

[jzz30]

wOw!! low boost got mine out... i dont know what to say...

[lexus082]

I talked to the UPS mechanic at work and he said to just leave the brake line connected to the caliper and then just to press on the brake with the caliper removed from the car of course. Which would force the piston out.

Someone else told me the piston may not be coming out completely straight and may be slightly crooked. He said to push the piston back in and then to try again using compressed air. Repeatedly until the piston comes out.

[jzz30]

the pressing on the brake should work but its messy! but ya gotta do whatchu gotta do...

[mobilyte]

to avoid the messy solution, first make sure you've removed the retaining ring and rubber boot around the piston. then get the piston out as much as you can with the compressed air. generously apply lithium grease around the piston and push it back into the caliper. repeat until the o-ring seal lets the piston out of its clutches.

[jzz30]

the easiest thing you could do is just replace it with a rebuild

[anthonyiez]

the easiest thing you could do is just replace it with a rebuild

i've been dying to say that. imo its just not worth considering how much quality remans cost these days.

[lexus082]

Yep, $230 for rear caliper from dealer and about $130 or so from auto parts store. Toyota Supra rebuild kit for the rear SC400 = $17.00 (covers both rear calipers).

[JIBBBY]

Why are you rebuilding your rear calipers? They should not need rebuilding...If you are unsatisfied with your braking performance I suggest you purchase a set of drilled and slotted rotors for all 4 wheels...Check Ebay they have great deals...Then use OEM or high quality brake pads...You braking should improve by 25% over stock....

[anthonyiez]

Yep, $230 for rear caliper from dealer and about $130 or so from auto parts store. Toyota Supra rebuild kit for the rear SC400 = $17.00 (covers both rear calipers).

wow, my cost from my local import part company is way way lower. plus they have 2 sets in stock. guess the internet isn't what it used to be.

[lexus082]

I'm rebuilding the left rear caliper b/c it is stuck. Its pressing the pads against the rotor even when the brake is not applied. Therefore wearing out the pads extremely quickly, not to mention its killing my acceleration and gas mileage. Haven't had a chance to work on it again.

[JIBBBY]

Oh the old sticky brake caliper...That sucks....

You may consider just visiting a local import junk yard and pick up a used rear brake caliper for cheap...Maybe even EBay....Almost cheaper then rebuilding and less headaches...Just a suggestion...

[mobilyte]

better to replace the seal, boot and retaining pin in your existing caliper instead of using a salvage yard pull. i doubt the salvaged caliper would be in much better condition after sitting unused for so long...

[JIBBBY]

better to replace the seal, boot and retaining pin in your existing caliper instead of using a salvage yard pull. i doubt the salvaged caliper would be in much better condition after sitting unused for so long...

True, but not really....The lexus SC400 calipers should not go out, I owned a used dealer ship for a few years and bought and sold altleast 50 or more SC400 and LS400 and some with super high mileage too. Not one ever had a caliper piston problem...Also I know a few heads in the lexus dealership and they tell me the calipers are very solid...If any are to go bad it would usually be the fronts as they support nearly 75% of the cars breaking power, and the rears contribute to only around 25%...Any used SC4 rear brake caliper should be in good shape 99% of the time...Your failed rear caliper is very uncommon....Just my 2 cents...

Rebuilding to new status is a good idea, however I am wondering if there is manufacturing defect going on with your single rear caliper..Hope the problem doesn't come back after rebuilding....How many miles are on your car?

[lexus082]

I got about 180,000 miles on it, so I can't complain even if it is uncommon. Still waiting for a day a am free to work on it without having to rush. Very busy right now. Will post results after work is completed.

[anthonyiez]

better to replace the seal, boot and retaining pin in your existing caliper instead of using a salvage yard pull. i doubt the salvaged caliper would be in much better condition after sitting unused for so long...

True, but not really....The lexus SC400 calipers should not go out, I owned a used dealer ship for a few years and bought and sold altleast 50 or more SC400 and LS400 and some with super high mileage too. Not one ever had a caliper piston problem...Also I know a few heads in the lexus dealership and they tell me the calipers are very solid...If any are to go bad it would usually be the fronts as they support nearly 75% of the cars breaking power, and the rears contribute to only around 25%...Any used SC4 rear brake caliper should be in good shape 99% of the time...Your failed rear caliper is very uncommon....Just my 2 cents...

Rebuilding to new status is a good idea, however I am wondering if there is manufacturing defect going on with your single rear caliper..Hope the problem doesn't come back after rebuilding....How many miles are on your car?

i actually had a lr caliper go bad on a 95 sc3 i owned. i had 3 sc3's and 1 sc4 and that was the only caliper problem.

[lexus082]

Well, I finally had time to rebuild my caliper. And since it was so easy I went ahead and rebuilt the other side as well. I might even rebuild the front calipers just for the hell of it. I thought it would be a little harder than it was. The difficulty level was equal to an oil change. The UPS mechanic at work said that often a caliper will freeze up due to old rubber brake hoses. The rubber starts to seperate from the hose and can cause a caliper to "freeze". Sure enough when I removed the piston from the caliper to clean it I found rubber material. He said its a good idea to replace the brake hose as well when rebuilding a caliper. Otherwise you will probably have to rebuild it again not too far down the road.

I had a little trouble getting the frozen caliper to release the piston. So I unbolted the caliper, left the brake line connected and pressed the brake a few times and it finally fell out. Couldn't get it out all the way with compressed air.

But anyway to sum the job up.... I removed the caliper from the torque plate, pressed on the brake pedal, removed the piston, disconnected the brake line, cleaned the piston and caliper, applied brake caliper grease to (piston seal, piston, caliper), installed piston seal, installed the dust boot over the piston, installed the piston into the caliper and installed the retainer ring for the dust boot. Two rear rebuilt calipers for $17.00 (using genuine toyota rebuild kit). Beats buying new calipers from Lexus for $230/each. Just thought I would share all this info. First caliper took me about two hrs b/c everything was new to me as far as rebuilding a caliper. Second caliper took about an hour. Again, very easy to do. Also, don't forget to bleed the brakes afterwards.