I'm researching the V6 front brake upgrade for my buddy's '86 4 cylinder and want to run this past the experts:

The front rotors off a '94 SR 3.5l Montero SR are listed as 27mm thick by 276mm wide. These seem to be the thickest factory type rotors, and very inexpensive, new. Will these fit the stock '86 hubs and clear the knuckles and steering arms? (I know I will need matching '94 SR backing plates/dust shields.)

Front dual piston calipers and mounting brackets from the same '94 SR. Should fit the stock knuckles, right?

The front brake hoses are listed as different lengths with ends that appear to be the same in pictures and thread type, Should I use the '86 upper hoses with the '94 lowers, or all '94 hoses, or will the '86 hoses fit OK?

The booster should be from a V6 Gen 1 with a 15/16" master, correct? Late '88 4 cylinder masters seem to have the larger 15/16" bore, but have the same outlets as the '86 in pictures. The bore depth for the pushrod is about .060" deeper with the 4 cylinder master. Will this physically fit the V6 dual diaphram booster so I can use the same lines, or would it be easier/better to grab the V6 lines? (A new V6 master is alot less $ than the late 4 cylinder type.)

Would it be OK to use the stock '86 4 cylinder 7/8" master, single diaphram booster with the V6 dual piston calipers, or would it lose too much pedal travel and/or require too much pedal pressure?

One last question!

Will the later model (late 88-89 4 cylinders) 15/16" REAR brake wheel cylinders fit the '86 backing plates? (Originally 7/8") I changed to 1/16" larger rear wheel cylinders on my tail heavy Scrambler and it helped a bit, they cost the same as stock replacements.

Thanks!

BTT... Anyone have advice on this?

I have the 88/89 rear cylinders on my 87 backing plates.

The booster I used was from a V6 Gen 1 with a 15/16" master... Its way better than the 4 cyl single diaphram unit that came on my 87.

My 87 had the smaller master cylinder. The 15/16 V6 with the better booster provieds good pedal feel.

My swap


Rotor thickness is not a big factor, as long as they are thick enough not to warp. As far as running temperature and fade what does matter is the amount of surface area to disapate heat.

I can only tell you what worked for me... I used GEN 1 V6 parts. Decent setup on a 4 cyl SWB.

Kevin

Great write-up Kevin! <img src="/forums/images/graemlins/cheers.gif" alt="" />

I want to use the later dual piston calipers, and rotors as they only cost a few bucks more than the single piston stuff.

It looks like you were able to use the stock '87 type hoses, right? Anyone know if the hoses need to be swapped with the dual piston calipers?

I'll use the late 15/16" wheel cylinders, ceramic pads, '89 booster and V6 master as you suggested. <img src="/forums/images/graemlins/kewl.gif" alt="" />

My friend has had his '86 since new, and he want's to keep it so it's worth upgrading the parts, especially since some of them are less or the same money and easier to find than the original replacements. He's running 31's, has a 20 gallon Jeep gas tank with a heavy skid plate, an extra 5 gallon can on the back, carries alot of camping gear and tools in the truck at all times so it's heavy and can use the extra braking power!

I did the V6 brake conversion and it is a piece of cake to do it. I changed everything, booster, master, rotors, calipers.

Braking power is way stronger. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Next project is dual piston and I wish there was a way for rear disc. I know, I know axle swap is the answer but...wife said <img src="/forums/images/graemlins/shame.gif" alt="" />

What a difference.


Javy

Thanks for the reply! One thing I forgot to ask is will the dual piston calipers clear 15x7 wheels?

Yes. You're not done with it already?








<img src="/forums/images/graemlins/smile.gif" alt="" />

It's for my friend's Montero, he needs to come up with the money first! <img src="/forums/images/graemlins/wink.gif" alt="" />

When I order the parts, should I get the late type lower hoses? They seem to be slightly shorter according to the parts description.

Quick question on the V6 brake parts.

I got the rotors and cal today of an V6
But I wasent able to get the brake booster loose.
I thought the were some bolts on the inside of the car,on the firewall?

Any tips?

(Looking forward to bigger brakes on my diesel <img src="/forums/images/graemlins/kewl.gif" alt="" />)

Four bolts on the inside of the firewall and of course the pin for the pushrod.

Kevin