View Full Version : The long awaited 4-pot Tacoma Front brake How-To

07-20-2010, 03:18 AM
First things first, there can be a large variety of ways to do this brake swap, i have thought of other methods beyond the one i used. And maybe further down the road i may choose to do it differently. Or someone may re-engineer my idea into a better one. Regardless my point is keep an open mind.

Secondly if you choose to do this swap, you are the one doing all the work, you are simply using the way i did it as a summarized method of a potential way of doing it. Therefore in case of failure, I AM NOT HELD RESPONSIBLE IN ANY WAY SHAPE OR FORM. YOU CHOSE TO TAMPER WITH YOUR OPERATING(or in some cases non-operating) BRAKES, NOT I. THEREFORE I WILL NOT AND CAN NOT BE HEAD RESPONSIBLE FOR YOUR ACTIONS. I state this only because brakes are really reallly REALLLLLY important on a vehicle and IF you do decide to do this, I STRONGLY recommend that you have complete confidence in what you are doing, as well as you test it out over and OVER ...and OVER again before you even THINK about take it out on a ROAD. Make sure that EVERYTHING is working the way it should. Again you choose to do this of your own free will, and therefore if anything is to happen it is on you(the reader of thread).

Thirdly I have written this in a way that will assume that the reader has previous knowledge of how the workings of their Toyota operates. I will not explain how to take off the knuckle or how to put it back on. Or how to bolt up the Brake Caliper, if you do not know how to do such please do not do this. But if there is ANYTHING confusing in my wording or if there is anything you guys want further pictures or explanations on then please let me know. And if my grammar or spelling lacks anywhere then let me know please.

With that disclaimer out of the way....

What you will need if you have a 1987-1989 Toyota Celica Alltrac(GT-Four) ST165:
If you have any other model/year of Celica, i leave it up to you to engineer it.
(as for the ST185, it is basically the same, with the exception of needing to buy ST185 discs, since you already have them...duh)
-Front Right and Left 09 Toyota Tacoma Brake Calipers:
-Front Left and Right ST185(1989-1993 Toyota Celica Alltrac) Brake Discs(rotors)
-New Brake lines(preferably SS...mostly cause it would be a good idea..just spend the 90 bucks):
-2x Grade 8 1/2 inch diameter bolts 2 inches in length:
-2x Grade 8 3/8 inch diameter bolts 2 inches in length:
-2x Grade 8 1/2 inch diameter hole Lock washer:
-2x Grade 8 3/8 inch diameter hole Lock washer
-2x Grade 8 1/2 inch diameter hole Lock nylon nut
-2x Grade 8 3/8 inch diameter hole Lock nylon nut
-a dremel of some nature or a metal file, i would use a metal file just to make sure you do not take away TOO much material, it will take FOREVER, but it will be worth it in the end.
-1/2 inch drill bit and drill
-1/2 inch steel tube, the thicker the better, which gives you more to work with; get at least 6 inches of it; there will be a lot of trial and error of getting it perfect

This is why you need ST185 brake discs, picture below is the caliper mock mounted on ST165 discs:

First thing to do is pull front Knuckles/Hubs off. If you do not know how to do this..STOP READING and do not do anything more please for your own sake.

Then Drill out the top hole for the stock brake calipers with 1/2 inch drill bit, example:
I picked the top hole to drill because there is more material there to hold and keep it strong, the lower bolt hole has less, and therefore if I drill it out, it will become considerably weaker.

Then dremel or file away these edges on the knuckle, try and file it so that everything remains flush with the mount hole surface.
I refer to these edges:

In the pictures you will note that the "dust shield" is not there, the knuckle/hub shown is merely an example of one, you will be able to retain your stock dust shield if desired.

Next you will dremel off the lifted flat surface and make it flush with rest that caliper edge highlighted in the picture below, due to the fact that it will make contact to the wheel spacer/rim dependent on your setup.
Here is a none molested photo to assist:

Now that you have done that, Mock test your calipers on your knuckle/hub(NOT ON THE CAR) and make sure that the caliper does not make any contact to the rim and or spacer.
Again if you can not figure out how to mock test it right now with the correct bolts, please stop reading.

You should also note that the nut and lock washer will be on CV axle side.

Alright now that you have mocked them up, you will see that the 1/2 inch bolt works perfectly and will hold tight.
Where as the 3/8th bolt will not be as behaved.
you will notice this gap:
No need to panic. The 3/8th bolt will fit in there...but here comes the 'shitty' part. You will need to create threaded half moon shims to compensate for the space..this part took me hours upon hours with a metal file and a grinder just to get 4 good shims(2 per side, one to compensate for the gap in the caliper and the other for the knuckle). These shims which we put into the holes and then slide the bolt in and make sure to have NO PLAY what so ever...and yes really this takes forever to get them just right.
Examples of the shims:
I tapped mine just to make sure it compensated as much of the gap as possible.

I had about 2 pieces of this 6 inch long 1/2" diameter steel tubing and tapped the whole thing, filed and grinded and took centuries to get them right.
As you can see below i took off too much material with the grinder, thus I suggest the metal file. When I used the file, I was able to get it perfect

Now that you have your shims made to compensate the gaps around the 3/8th inch bolts, you can can attach the SS brake line. Make sure to use the COPPER o-rings, and I used the stock Toyota Celica COPPER banjo bolts, cause the ones supplied by Technafit lines were too long for these calipers as seen below(otherwise you will want to use extra copper o-rings).

Note this is with the bolt all the way tightened, with out the copper o-rings, therefore if you were to have another copper o-ring it will be fine....BUT using the stock banjo bolts would be a better way of doing it.

The brake line should look like this but cleaner ;):

All bolted up it will look like this:
The bleeder valve has to be up top. use the picture as reference to what i mean.


Finished product:

Thank you, and I hope this is helpful to many. Take care all!
And Please be careful when doing this mod and make sure you have complete confidence in the integrity of your design, and for the love of God, make sure all your bolts are tight and that there is NO play in anything!!

07-20-2010, 08:10 PM
Good write-up Dan!

Can you explain a little more about the threaded half-moon shims? I'm a little lost on that part....

07-23-2010, 02:36 PM
Good write-up Dan!

Can you explain a little more about the threaded half-moon shims? I'm a little lost on that part....

Thank you.

Sure dude will do, it will likely be easier if i just post more pics of such.
It would make it more clear :)

07-23-2010, 02:57 PM
Nice upgrade! Certainly something for those that are more adventurous and don't want to drop coin on a full on custom setup or care for something larger than the 185 JDM twin piston conversion.

The Captain
07-23-2010, 10:16 PM
I wonder how much it would cost to have the holes welded shut and re-drill and tapped instead of the threaded half moon spacer.

07-23-2010, 10:33 PM
I wonder how much it would cost to have the holes welded shut and re-drill and tapped instead of the threaded half moon spacer.

Probably not much if you have the stuff to fill it, which I'd use an bolt that is unthreaded. As for drill and tap... well, that's easy to do, so diy.

07-23-2010, 10:34 PM
I wonder how much it would cost to have the holes welded shut and re-drill and tapped instead of the threaded half moon spacer.

I am not sure...but it would be "wiser" way to do it. That is for sure. MY way has held up fine for me. But it is really the "budget" way of doing things.

07-24-2010, 12:18 AM
how is the rear conversion going?

07-24-2010, 02:38 AM
poorly, the discs i got where too thick....still hunting down ones that would work.

07-24-2010, 09:58 PM
Why not try something like a 3/8 threaded bolt with a 1/2 inch shoulder instead of the shims?

click on US Shoulder Bolt dimension table to see how its explained

that is a copy and paste quote from alltrac.net's thread...that is another good idea. That i did not even think of...so someone can try that too. Would def be a better idea than the shims. And near exponentially easier!

07-24-2010, 10:36 PM
nice work! just a couple questions that come to mind:

1. what does the static bias end up looking like?

2. any particular reason you went with the truck calipers instead of some alloy calipers like the 300ZX (also made by sumitomo)? not a big deal for a street-only car, but i would imagine the selection of race pads for truck calipers wouldn't be as plentiful. i believe the LS430 monobloc calipers use the same piston sizes as the trucks and are significantly lighter. they're radial mount though, so you'd need brackets.

3. i was going to mention the half-moon thing too. any reason you couldn't just tap the knuckles or calipers for larger bolts?

4. maybe you could post up the distance from the wheel mounting surface to the outer face of the caliper so that anyone interested could check to see if their current wheels would clear the calipers. i needed new wheels for my setup, but i used really wide porsche 996 brembos.

5. any chance these could be paired with larger rotors as well? i bet the LS400 or even the supraTT rotors would fit with a caliper bracket.

that's all i can think of. now go take it to a track and let us know how it works! :D

07-26-2010, 03:31 AM
I think the main thing is weight. Those calipers are heavy.That's a lot of unsprung weight that'll slow down your suspension movements and probably just jack-up your suspension frequency.

08-19-2010, 04:41 PM
another tip for those style calipers, throw some anti-seize on the pins where the pads slide on, and on the top and bottom edge where they slide through the caliper.

no need for much, but enough to have a nice coating, you'll thank yourself later