How to Upgrade your 1st Gen. Toyota 4Runner Brakes

  • Thread starter Scenic WonderRunner
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Scenic WonderRunner

How to Upgrade your 1st Gen. Toyota 4Runner Brakes....

Grim Reaper offered up some great ideas on upgrading our 1st Generation Toyota 4Runner Brakes over here.

Post up your thoughts, methods, pics and good links to parts.

Can we also upgrade the rear brakes?

Another REAL important upgrade if you are still running the IFS is replace the rotors and calipers with the set from a 93 v6 with the 31 inch tire option. totally bolt on. Then throw a 1 inch master on it. With that combo I can lock the front 33's on dry pavement. I am still running the stock 86 booster and it has a stiff peddle. A 93 V6 booster is a bolt on as well.
I went through hell finding a reservoir 2 years ago and after it was all said and done this was looking like a really good deal.
Unbolt the proportion valve arm off the back axle and zip tie it all the way up.

Here is some comparison pictures of what stock 86 parts look like compared to stock V6 31 inch tire parts.



Can we also upgrade the rear brakes?
there are numerious disc swap kits out there. they all use GM metric calipers and discs. not a bad option.

personally im working on a way to get my front 3rd gen discs on the rear of my truck, since i upgraded to tundra brakes on the front. its going to require some machining of the flange to fit the discs but it shouldnt be too much of a problem. just time and money, and fabbing a bracket!


I may have a bit of info to contribute :D -- please excuse the offsite links, there was some further discussion in some of the threads that may provide more info
Got my T-100 calipers on today. I already changed out the master cylinder, so I don't know how the brake pedal would feel with the bigger calipers and stock master cylinder. Here's the rundown:

Here are the original calipers

you can actually see that the leading piston (one on bottom) is smaller than the other one - note the S12+8 casting mark. Toyota uses standard calipers on several different models, the cast mark identifies which ones are identical (no difference in the cast mark to indicate left or right side though)

Here's what happens if you try to use the T-100 (S13WB cast mark) calipers with the stock rotors.

BTW, when I was getting parts I told the parts guy it was a '95 T-100 4wd.

So I got a pair of T-100 rotors to go with the new calipers and pads - the only thing that needs to change for the rotors is to push the bottom of the backing plate away from the rotors about 1/8" to keep it from rubbing - otherwise everything just bolts on

Here are the '88 4runner rotor specs:
# of Bolt Holes:6
Bolt Circle Diameter:5"
Maximum Lateral Runout:.004"
Thickness When New:.79"
Discard Thickness:.709"
Vented / Solid:Vented
Center Hole Diameter:3.942"

here are the T-100 rotor specs:
# of Bolt Holes:6
Bolt Circle Diameter:5"
Maximum Lateral Runout:.004"
Thickness When New:.985"
Discard Thickness:.905"
Vented / Solid:Vented
Center Hole Diameter:3.942"

So the only real difference is thickness and overall diameter - if you saw the "height" is also different, that's only because the rotor is thicker and the height needed to change to keep the rotor centered in the caliper.

The calipers are a simple bolt on affair, the only thing necessary is little bit of trimming to the backing plate

Finished product (kinda finished, I didn't have the rotors on yet in these pics)

for some other caliper options look here
Here's the thread where I did the master cylinder upgrade

Here's what I found on Toyota caliper cast marks awhile ago:
8173/8174 95 ALL S12WE

4 Runner
8171/8172 95-91 ALL S13WB
8169/8170 91-88 ALL S12W R/L
4407/4408 87-84 ALL (4 Cyl) S12-8

1478/1479 92-91 ALL S13WA
4407/4408 90-75 ALL S12-8

Pickup, Hi-Lux
8171/8172 95-91 T100 Pickup 4WD 1/2 Ton S13WB
2011/2012 95-89 2WD 4 Cyl. l 17S R/L
1242/1243 95-89 DRW AISIN 1 R/L
8567/8568 91-89 Long Bed F18Q R/L
514/515 91-8/83 2WD, 1/2 Ton AISIN
4407/4408 88-86 Long Bed 4WD W/4 Cyl. S12-8
4409/4410 85-80 Long Bed 4WD S12+8
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so I was looking at my friend/roommate's spare small block modified circle track car (also has a go cart with a CBR929 engine :D) and the front calipers caught my eye because they look oddly similar to the T100 calipers I got a little while ago. I'm not planning on swapping to Wilwoods, but it'd be some good bling.

so I started taking some measurements
the 1" mark is at the center of the bolt in this picture, so the mounting hole spread is 3.5" - the same spread as my 1st gen and t-100 caliper (should be the same for the 1st and 2nd gen truck/4runners)

caliper height from the bolt centerline - just shy of 3"

caliper depth - the inside of the mounting ear is at the 1.5" mark - caliper centerline 1" past that - 5.25" total width

BTW, my roomy also said that Jaguar used the same 3.5" mount hole spread on a number of older cars, but with 6 piston cast iron calipers :D The other standard mount hole spread for Wilwood is 5.25" center-center, and you can get either mount pattern in a variety of caliper piston sizes, up to 2" (the S12W caliper is ~1.75" piston diameter)

The T100 S13WB calipers (90's V6 caliper with matching piston diameters)

3.5" caliper mount hole spacing (excuse the skuz, I only bothered to clean and paint the part you'll be able to see once mounted :D)

caliper height from bolt centerline - just shy of 3"

caliper depth - the inside of the mounting ear is at the 1.5" mark - caliper centerline 1" past that - 5.25" total width


time to upgrade the Master Cylinder in preparation for my T100 caliper swap - the bigger pistons on the T100 calipers need a slightly bigger MC bore. The '90s T100 1 tons have a 1-1/16" MC bore vs the popular 1" bore found in many mid 90's 4runners and LandCruisers - bigger isn't necessarily better when it comes to the MC bore. A bigger bore moves more fluid, but produces less hydraulic pressure with the same amount of force on the pedal. In this case, I wanted to match what was available on the T100.
*note* unless you also swap in the dual diaphragm booster, don't bother with the 1 1/16" MC - pedal was too hard, I swapped back to the 1" MC

here's my $50 ebay master cylinder, brand new - note the 1-1/16" cast on the side

out with the old 7/8" bore MC

in with the new (and the aluminum looks much prettier than rust :D)

it was a simple bolt on swap, no drama. The front brake line needed to be bent a bit to match up with the T100 MC port. I didn't bother to bench bleed it, prefering to do it on the vehicle with a rag under the lines. Initial driving impressions are good with pressure building and the pedal firm very near the top of it's travel, though when I get the T100 calipers on it should soften up a bit. I would not recommend this size MC with the stock 1st gen calipers as it could get tiring to drive with the extra firm pedal. On a 2nd gen with the "S12W" calipers though, it might be a nice upgrade that would give a better pedal feel.

I cannot personally vouch for this cross reference:

Brake Master Cylinder for the following 1 TON Models:
1994 Toyota T100 Pickup : 4-2694 2.7L DOHC
1994 Toyota T100 Pickup : V6-2958 3.0L SOHC
1995 Toyota T100 Pickup : 4-2694 2.7L DOHC - Notes: w/o ABS
1995 Toyota T100 Pickup : V6-3378 3.4L DOHC - Notes: w/o ABS
1996 Toyota T100 Pickup : 4-2694 2.7L DOHC - Notes: w/o ABS
1996 Toyota T100 Pickup : V6-3378 3.4L DOHC - Notes: w/o ABS
1997 Toyota T100 Pickup : 4-2694 2.7L DOHC - Notes: w/o ABS
1997 Toyota T100 Pickup : V6-3378 3.4L DOHC - Notes: w/o ABS
1998 Toyota T100 Pickup : 4-2694 2.7L DOHC - Notes: w/o ABS
1998 Toyota T100 Pickup : V6-3378 3.4L DOHC - Notes: w/o ABS

Here are some other MC sizes toyota used in the standard 4 bolt hole mount:
86.5 - 89 Supra = 1" bore, 4 hole mount
82- 86.5 CelicaSupra = 15/16" bore, 4 hole mount
86 - 89 4runner = 13/16" bore, 4 hole mount
90-95 4runner = 1" bore, 4 hole mount
~91 - 95 MR2 = 7/8" bore, 4 hole mount



Wilwood manual brake proportioning valve - the shiny fittings are SAE standard for 3/16" brake line (the valve uses standard thread - Toyota is metric), the only metric (Toyota) fittings are the rusted ones that I re-used on the master cylinder, the Toyota fittings worked perfectly with the 3/16" line and mixing them on the line made it easy to adapt the valve to the MC
(note: all brake lines where bent with a tool, brake line doesn't bend very nicely by hand - it has a tendency to kink)

Took the LSPV off. The line that needs to get bent down to the flexible brake line is the one at the top of the LSPV - there is an -> next to the brake line on the LSPV. The line with an "F" next to it ties into the front brake line and can just be bent back or cut off . . . .

. . . . once you plug the front "T" I just took a fiting and put a big puddle of weld in the middle of it to make my own plug.
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I did this on my 84. I might have lucked into it, but most of the write ups for the solid axle 4runners called for land cruiser rotors. The hardest part for me was rebuilding the hubs because I had everything out to get to the rotors. The calipers I used were from a v6 4runner and I went ahead and used the master from the same truck. My reasoning was that it was a matched system for a heavier truck. My truck might be lighter, but I had larger tires. It was more than sufficient and has held up over the years.


I sold my 01 Tundra calipers to a guy that was upgrading his 4runner. Then I upgraded to even larger calipers!