question about v6 caliper brake upgrade?

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alteredraptor

alteredraptor

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i found a few threads about swappin in bigger calipers and a bigger master cylinder for a better brake pedal feel. i have plans on doing that to my truck, i already have a set of calipers, i just need a master cylinder. my question is, since there seems to be more than just one option, which master cylinder should i go for? i found these two Master Cylinder | Marlin Crawler, Inc. but i dont know the difference in them besides the price, so if some one can offer some insight that would be great. thanks ahead of time.
 
one's for a FJ80, one's for a V6 truck.
Land Cruiser MC's are a larger diameter, and since 1990 have been coupled to a dual-diaphragm booster.
Pickup M/C's are narrower, and mate up to the deeper mini booster.
I don't know much about cross-compatibility, but I imagine that the FJ80 M/C on a truck would make for a pretty harsh stop.

Good Luck!
 
I put the FJ-80 master on my 1983 pickup and upgraded to the vented rotors and larger V6 calipers. The brakes were awesome on that truck. Marlin's site says that both of those masters are 1" bore, so either one would be fine for you when upgrading to the larger calipers. And it says the 80 series master is on back order anyway, so if it were me, I'd buy the cheaper one.
 
I picked up a MC from a 92 V6 4 Runner along with the brake booster for use with my V6 calipers on my 4 cyl. 88 4 Runner. Brakes are great and cost less than the 80 series MC from Marlin. Complete bolt on other than a little trimming of the brake backing plate to fit the larger calipers.
 
I also just did the brake m/c but mine feels great and can lock up 35's. Have to keep the rears adjusted properly though.

The only modification I really had to do was cut and splice the wire on the new M/C cap for the level sensor.
 
FWIW 80-series masters are specifically used for SAS setups or rear disc upgrades. Everything else goes something like early truck and 4Runner's use the 1" master, later trucks and 4Runners (IIRC 1989-1995) use the 1-1/16" master to work with the rear drums and front discs with the ABS system.

As-in, I'm pretty sure my '95 is running a 1-1/16" bore, but it's possible b/c I wanted stronger stopping Yodaman put the 1" on instead. Just be sure you match your master to your needs, check with Marlin on this stuff b/c it is more of a factor if also changing out your booster at the same time. Also if equipped with it, recheck your LSPV for proper function and also check to be sure the rear brake shoe's are properly adjusted. The factory adjusters IMHO/E never keep up in adjustment to wear. Readjusting them is actually a part of the factory oil change interval service and you can easily get 1-2 clicks out of them every 3000 miles, especially if like me and in a heavily loaded 4Runner. LSPV valves go bad about every 80,000 miles or at least by then need a service to flush out the gunk in there that a line bleed just doesn't move enough fluid to get to. You need to pull it and disassemble it, rebuild it, and bench bleed it for best function.

*SAS people also tend to chuck the ABS and go with a manual proportioning valve to equalize the pressure front to back.
 
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A larger bore MC will move more fluid for a given distance of pedal travel. So if you upgrade only your MC, you would notice that it takes a lot less pedal travel to fully lock up the brakes. Adding the larger V6 brakes (which I can't remember whether it's dual pistons or just a larger single) gives more room for fluid displacement, so you really need the larger MC to get back to normal pedal travel.

The theory would be that by moving to a larger MC you may loose some of the "mechanical advantage" that you get from the ratio of MC bore size to brake piston size, so you will have to push with more pedal force for the same braking force, but honestly I never noticed the difference. The pedal travel I noticed, the force difference not so much. Upgrading to a dual diaphram booster means the booster would chip in more and your foot would do less of the pushing. So really with the larger calipers, bigger MC, and dual booster you'd ideally be back to near stock pedal travel and force, but the truck would stop better. I never upgraded to the dual booster but I certainly would have if I found one for a good deal.

EDIT: 1 more thing I forgot to mention, which I see that NorCalBorn already said...you need to adjust your rears. I don't think you will ever get a good pedal if the rears are not adjusted.
 
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also my truck is an 84, at the same time i did the master swap, i did a rear swap out of an 86, so it has bigger brakes in the rear and the v6 calipers in the front, i did not swap out my brake booster, but if i find one for a good price i to will do that too. and like was said my pedal does not travel very far, and it is much harder.
 
NorCalBorn said:
FWIW 80-series masters are specifically used for SAS setups or rear disc upgrades. Everything else goes something like early truck and 4Runner's use the 1" master, later trucks and 4Runners (IIRC 1989-1995) use the 1-1/16" master to work with the rear drums and front discs with the ABS system.
Click to expand...

Not totally true. There are two 80-series master cylinders. Those used on FJ80s (1990-1992 with 3FE engine) are for disk front and drum rear. Those on FZJ80s (1993-1997 with the 1FE) are for four wheel disk trucks (both abs and non-abs). I've never seen a 1-1/16" master cylinder on a mini-truck. Not saying they don't exist, but I've harvested several over the years and they have all been 1".

I run a V6 booster, mini-truck 1" master cylinder, vented rotors, and V6 calipers on my 1985 4Runner keeping the drums in the rear. I run the FZJ80 master cylinder, FJ62 booster, vented rotors, and V6 calipers on my FJ40 with rear disk.
 
i put vented rotors and V6 calipers on my 80 truck. problem was the body of the caliper rubbed severely on the inside of my wheels. (black rock crushers, i think)
So the solution was to install the shortest wheel spacers
 
I had the same issue. I mounted my wheels and I always spin them before I drop the truck off the stands. I went to turn them and they wouldn't spin at all because they were in a bind against the calipers. I swapped the old ones back on and decided to address the issue later.

I ended up buying a set of 35's and at full turn, the side lugs on the tires were catching my front springs. So, I bought 4 1" spacers (in hindsight, I should have went with 1.5", to give me more options with later model rear axles). Anyway, this was when I went back and attempted the brake swap again. Plus, the truck refused to stop with 35's. I had to plan to stop at stop signs a month out on my calender because braking was so bad. I swapped the calipers and M/C, did a full flush and fill, force bled my lines with a compressor, and adjusted rears. The differences was night and day!
 
It's not the rim size that matters, but more the back spacing. The v6 calipers have a wider body which interferes with the rim where it leaves the hub face. A spacer, even a small one, will move the center of the rim away from the hub, adding the clearance needed. I have heard you can grind the caliper to make it work, but I wouldn't trust it with the pressure it deals with.
 
Your original MC should be 13/16" bore. Go with the 1" bore - I tried the 1 1/16" MC and didn't like it (especially after my brake booster popped and I lost power assist). I got my 1" bore MC from a junkyard for <$10, but it looked relatively new and I made sure the pedal didn't fade before I unbolted it.


Some MC size research - anything below with a 4 hole mount should bolt on
MC SIZES said:
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
96 - ? 4runner = 1" bore, 2 hole mount
~91 - 95 MR2 = 7/8" bore, 4 hole mount
Click to expand...

. . . and just to throw some caliper info into the thread
My T100 caliper upgrade on 1G 4runner
CALIPER CASTING MARKS said:
TOYOTA TRUCK
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

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

TOYOTA TRUCK
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
Click to expand...
 
corax said:
Your original MC should be 13/16" bore. Go with the 1" bore - I tried the 1 1/16" MC and didn't like it (especially after my brake booster popped and I lost power assist). I got my 1" bore MC from a junkyard for <$10, but it looked relatively new and I made sure the pedal didn't fade before I unbolted it.


Some MC size research - anything below with a 4 hole mount should bolt on


. . . and just to throw some caliper info into the thread
My T100 caliper upgrade on 1G 4runner
Click to expand...



keith thanks for the master-cylinder it has helped out with the braking on my 84, that and the 86 rear, my ebrake works now.
 
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