View Full Version : Rebuilding JDM GT4 Twin Pot Calipers

10-17-2005, 08:17 PM
I picked up a pair of JDM twin pot calipers from Chris Dittrick a few months ago. I figured that I might as well clean them up and rebuild them so I took them to a machine shop, dismantled them and had them sanblasted. I sprayed them with a high heat aluminum paint instead of having them powdercoated and spending more money.

I went to NAPA to find a rebuild kit for the twin pot calipers so I asked them if they had any listing for twin pot calipers for celica all-tracs, they told me the only listings that they had are for 88-89 all-tracs. So I went with that rebuild kit which only consists of seals and rubber boots, and they fit perfectly into the GT4 calipers. I still have to take the GTS calipers off and use the rubber boots for the mounting bolts since the machine shop lost the ones for the GT4 calipers but the GTS ones should work. I am thinking of taking my drilled rotors to the machine shop and having them sandblasted as well to get all that rust, dirt and brake dust off of them.

Well, here are some pics and I will post more of the progress as I go... sorry for the size...

Before Sandblasting and paint....

After Sanblasting and paint...

10-17-2005, 08:49 PM
they look great Keoni!

10-17-2005, 09:50 PM
You, your buddies, whomever, does GREAT work!

10-17-2005, 10:05 PM
I'll give you 10 dollars for them!

10-18-2005, 01:32 AM
Looks good, also nice to hear that you found a rebuild kit that works with those calipers. :)

10-18-2005, 02:32 AM
Definitely give us some feedback as well. There's been speculation that the actual piston surface area of the twin pots was a bit lower then just the one piston. Which I've always its advantagous to have more piston area, and that it equates to better stopping power.


10-18-2005, 03:33 AM
You, your buddies, whomever, does GREAT work!
Thanks Sean! I am actually happy with the color because I did not want to make the caliper look too ricey and the aluminum just makes it look like a new out of the box part.

I took a couple of pictures of the old brakes and you guys get a good idea of how salty the air here in Hawai'i is, also notice the corrosion on the 7th gen GTS rims. I am most likely going to have them powdercoated although I am not too sure what color yet. Once again I am sorry about the size of the pics...

I took the drilled rotors to the machine shop and in a couple of days I will have them back clean and rust free. I am going to paint the rotor hat the same aluminum color as the calipers.

Clayton seemed to think that the stopping power of the twin pot brakes felt alot better than the single pot, so I am hoping that I agree with him once I get these installed.

10-18-2005, 03:41 AM
Just make sure to not confuse on where the benefit is coming from. You did rebuild the caliper, so it should in theory work really well!

Cant compare a worn out caliper, to a rebuilt one, but you know what i mean :)

10-18-2005, 03:50 AM
Damn those caliper look clean! I wonder if the single pot calipers would be better though? Always makes me wonder why toyota went back to single piston on the gt4.

10-21-2005, 08:41 PM
Just got the drilled rotors back from sandblasting and I wasted no time painting them to ensure no rusting. I painted the whole rotor so the pads will take off the paint where they make contact to the rotor and the rest of the rotor will be rust-free.

Problem is finding new pads for these JDM twin pot calipers. With the help of Mafix I am going to order some low metal organic pads from summit racing but they wont have any in-stock until November 2nd so I have to wait until then. Good thing this car is not my daily driver.

On to the pics...

11-18-2005, 09:33 PM
I finally got the EBC green stuff brake pads in and I went ahead and put the front brakes back together. I ran into a problem though with the brake pads... the pads on the outer part of the rotors wouldnt slide into the caliper bracket and it was only interfering by about 1/16", so I grinded that part down. I dont know if that is a common problem but I am sure that the pads are suppose to sit further into the bracket or else it wouldnt make contact with the rotor at all. Also I am sure that I still need to bleed all four corners and the master cylinder because the pedal still feels soft.

I need to break in the pads until the brake-in material is gone and the paint on the rotors have been scraped away. Right now the pads are making a scraping noise only when I apply the brakes.

Well here are some pics, I will let you guys know the difference I feel once the brakes are properly broken and the air is bled out of the system...



11-19-2005, 12:45 AM
WOW, looking great man! What a difference!

11-20-2005, 04:18 AM
great work!

12-03-2005, 07:12 AM
Nice work, notice any difference yet?

12-05-2005, 09:49 PM
The difference is not something monumental but there is some better stopping power now compared to the single piston calipers. but like Sean said you cannot really compare rebuilt calipers to the old single piston worn out ones. If you are on a budget and you just want something that performs a bit better than stock than I guess you could opt for twin pot calipers.

Twin Pot Calipers from Chris Dittrick= $150 shipped
Rebuild Kit=$52
EBC pads=$60
Total= $262

12-06-2005, 05:03 AM
A set of zinc coated rotors are a lot nicer.. they don't rust....