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View Full Version : 5th gen brake upgrade



85gtsblackman
10-05-2009, 02:56 AM
As some of you may know... the later model (92-93) 5th gen Celica GT and GTS (minus the vert) wear some fairly decent sized front brakes (277mm diameter vs. the 6th gen ST's 254.7mm diameter rotors and the 6th gen GT's 275mm diameter rotors). There was a 1/2 price sale at a local pick and pull so I picked up a pair of front calipers and brackets from a 92 Celica GT and had been saving them for a while now as an upgrade in size to my Celica ST's dinky brakes. It's purely cosmetic... and was cheap, so I went ahead and did it.

I finally ordered some rotors last week and today went ahead with the install. Low and behold... there was a difference. The 5th gen Rotors did not sit flush on the 6th gen hub because the bore on the center hub of the 5th gen was much smaller than the 6th gen. After some test attempts, I got out a caliper and measured the bore diameters on the 5th gen GT (or GTS) rotor and the stock ST rotor. Sure enough... almost a 1mm difference. I believe it was something like .8mm difference... but yeah... enough that the 5th gen rotor did not sit flush to the 6th gen hub. After a few calls to local machine shops... I ended up whipping out our porting tools and after a few minutes... I had the 5th gen rotors sitting flush to the 6th gen hub. Next... was the calipers.

The 5th gen Calipers do bolt-on to the 6th gen knuckles without much problems, and the spacing between the spindle and the caliper was correct that the rotor's diameter fit as if it was stock. The problem was... after I tightened down the calipers, they were offset wrong and ended up touching the rotor, glueing it in place. After some quick thinking... I added some spacers (simple washers) between the knuckle and the caliper brackets and voila... perfect fit. The Stock ST brake lines then bolted on and everything was set. System was then bled and the car ran and stopped great.

So all in all... we all learned today that the 5th gen Calipers are ALMOST direct bolt-ons... and the rotors are ALMOST direct fit. It will take very little work to get them all together... but in the end... it works like a charm. I would imagine the same issues may be present for any or all of the other possible big brake options for the 6th gen Celicas (7th gen Big Brake kits, Scion tC Big Brake kit, etc...) Experiment and share the info... =]


this was stolen from 6gc but i posted it here cause

1 its usefull
2 i plan to do this
3 it took me 45 mins to find it


yes i know my car is a beater but when i brake the wheel does a slight jolt right and i think i have a sticking caliper cause my right wheel has more brake dust than my left

qatar11
10-21-2009, 07:13 PM
I used ST165 Calipers and Rotors - they were a SIGNIFICANT size increase... I had to use a bumper washer to offset the caliper correctly...

Sadly I have no photos to share :(

KoreanJoey
10-22-2009, 06:18 AM
That's what I had to do with the ST185 rear calipers, well, the washer, didn't do anything with the rotor.

Car_Barn_Bandit
06-19-2010, 08:53 PM
So, I had a set of front Brembo blanks ordered for the Fail Project (92' US GTS) and I was just going to drop them on the 91' CAN GTS. No such luck. The Brembo rotors are significantly larger then the OEM rotors. They sit on the hub just fine, but the heat shield, caliper and bracket will not get anywhere close to fitting.

Annoying part is, I see identical part numbers from ToyoDIY on the two different car models. I wonder if someone changed the hubs out from a different year, and this is the result, or if the catalog is questionable.

At any rate, I am having the brake assemblies from the Fail Project shipped out to me, and I will keep you all posted on what matches to what. I really hate this gap inside the wheels. I also like stopping.

Galcobar
06-19-2010, 09:42 PM
Per my post in the fifth-gen brake upgrade sticky:


Rear discs on 90-93 GTS and 92-93 GT were 269 mm (90-91 GT got rear discs as an option). Front rotors on 90-91 GT/GTS were 255mm, up to 277mm in 92-93 (same size as All-trac rotors, but w/out the dual-piston calipers).

Front rotors on 94-99 GT were 275mm, but were 3 mm thicker than the 92-93 GT/GTS rotors, and 6 mm thicker than the 90-91 GT/GTS. Rear discs on 94-95 GT were the same dimensions as the fifth-gen rears (except for the centrebore), but in 95-on they went from 10 mm thick to 9 mm thick, though retaining the 269 mm diametre.

For 5SFE-powered Celicas:
Front rotors
90-91 255 mm diametre, 22 mm thick, 54 mm centrebore
92-93 277 mm, 25 mm, 54 mm
94-99 275 mm, 28 mm, 55 mm

Rear rotors
90-93 269 mm, 10 mm, 54 mm
94-95 269 mm, 10 mm, 55 mm
95-99 269 mm, 9 mm, 55 mm

For 4AFE-powered Celicas
Front rotors
90-91 238 mm, 22 mm, 54 mm
92-93 255 mm, 25 mm, 54 mm

93celicaconv
06-19-2010, 10:41 PM
Are the front & back rotors for a 1993 vert the same as the information provided under "For 5SFE-powered Celicas:"?

Car_Barn_Bandit
06-19-2010, 10:53 PM
Interesting. To upgrade to AllTrac dual piston fronts, would I also need to upgrade the Master Cylinder as well. Good stuff.

The rotors fit the hub without issue, I am just curious to see how compatable the extra hardware is utilizing the 91 hub and bearing. I have the ability to upgrade the entire assembly, but it would be a hell of a lot more convenient if I just had to swap calipers and brackets.