Author Topic: Big Brake Mod (IFS Mod & Rear Disc) (Read 28567 times)

golana · « **on:** Mar 16, 2011, 01:47:55 AM »

This Thread is Featured in our Tech from our Forum Members section!

I machined a set of IFS hubs for one of my good friends, and he is going to be making an install video of the Big Brake Mod on the front of his truck. I will be posting the video here when he is done!

*** i reuploaded the images to my website instead of photobucket, because they changed their policies, and no longer honor the decade-old members with free accounts! ***

Well, i have a 1985 toyota 4x4. i had the stock brake system, and it wasnt bad, but it wasnt anything special, thats for sure!

i did some research, and came up with everything i needed for the swap!

tools and stuff needed:
1/2" fine thread tap
1/2" drill bit
angle grinder (or lathe if you have access to one)
drill
4x 1/2" fine thread, gr.8 1.25" long bolts

first off, for the front, i used:
1998 Toyota Tacoma rotors
1994 Toyota Pickup v6 calipers
1986 Toyota Pickup hubs

some slight modification had to be done to both the calipers and the steering knuckle. both are no big deal!
you do have to modify the IFS hubs though... if you dont have access to a lathe, you can use an angle grinder, just be careful not to take off too much material...

IFS Hubs

had to throw the hubs on my lathe to turn down the little ear things...

i had to take down a bit more than this, but you get the idea

use the 1/2" fine thread tap on the mounting ears of the caliper.
then use the 1/2" drill bit on the mounting ears of the solid axle knuckles. you just need to hog out enough material to fit a fine thread 1/2" bolt.

now the 98 tacoma rotors fit overtop of the hubs!

1/2" tap

tapped the 94 V6 calipers (i think these ones are 86 calipers though... notice the 2 sizes of pistons... the smaller ones are closest to the camera, the larger pistons are under the brake line fitting)

the calipers now mount on the outside of the ears, instead of the inside, but its no less strong... now all i have to do to change rotors is remove the wheel, and unbolt the caliper!

Here is a before and after:

for the rear, i used: (you will have all this stuff laying around after the front is done)
1985 Toyota Pickup solid axle rotors
1985 Toyota Pickup solid axle calipers
1985 Toyota Pickup solid axle lug studs

i pounded out the old studs off the axle shaft and had to grind down a hair off the axle on the inside where the rotor has to sit...

once the rotor sat flush, i just installed the longer solid axle studs and bob's your uncle!

pretty good stuff! i had to make a set of wheel spacers (only 1/4" though) so i could bolt the wheel on... the shoulder of the longer studs is a hair too far out...

i saw what i needed to do, so i drew up some brackets on some 1/4" steel (i think it was 1/4"... either that or 5/16")

ohhh yea!

i cleaned the pieces up a bit, then marked where i needed to, and drilled holes

i didnt like how much space was left...

tapped the 85 solid axle calipers to 1/2" thread

i ended up cutting out another set, slightly smaller, and welding them to the plates. super beef!

love it!

no more gaps, and no chance of ever bending it haha

Braking:
after doing this swap, the brake pedal became SUPER stiff! it was really hard to push the pedal, but i could still stop. The solution to this, is a Tacoma brake booster! i also used a Tacoma brake master cylinder

i am not running a proportioning valve, and the rear does lock up before the front, so its a little sketchy driving on ice or super slippery surfaces, but the increased braking power is just unbelievable! on the trail, its just perfect! for street use, i recommend a prop. valve! i was pulling a 2300lb, 6x12' dual axle uhaul trailer loaded with my in-laws stuff when i helped them move, and had absolutely no problem stopping it!

i hope this writeup helps anyone out who is interested in doing this swap too! happy wheelin!

Peterbuilt84 · « **Reply #1 on:** Mar 16, 2011, 02:13:09 AM »

Thanks for the writeup

Do you think the braking could of been helped with just a new master cylinder, or was the booster needed also?

golana · « **Reply #2 on:** Mar 16, 2011, 03:02:27 AM »

Quote from: Peterbuilt84 on Mar 16, 2011, 02:13:09 AM

Thanks for the writeup

Do you think the braking could of been helped with just a new master cylinder, or was the booster needed also?

the stock booster didnt have enough vacuum to help push the pedal down. the only reason i swapped master cylinders is mine seized and wasnt releasing the fronts... any time i stepped on the brakes, the fronts got tighter and tighter, till i couldnt drive, even in 4lo-lo...

the booster is a must.

SloCrawler · « **Reply #3 on:** Mar 16, 2011, 08:21:42 AM »

nice right up, that widend your front correct?

golana · « **Reply #4 on:** Mar 16, 2011, 11:57:42 AM »

Quote from: Chrstphrtptts on Mar 16, 2011, 08:21:42 AM

nice right up, that widend your front correct?

correct. using the IFS hubs vs the SA hubs widens your wheel mounting surface by 3"

SloCrawler · « **Reply #5 on:** Mar 16, 2011, 01:16:07 PM »

you think this all works the same for pre 85 front axles and ifs rear axles?

Peterbuilt84 · « **Reply #6 on:** Mar 16, 2011, 01:22:34 PM »

Quote from: golana on Mar 16, 2011, 03:02:27 AM

the stock booster didnt have enough vacuum to help push the pedal down. the only reason i swapped master cylinders is mine seized and wasnt releasing the fronts... any time i stepped on the brakes, the fronts got tighter and tighter, till i couldnt drive, even in 4lo-lo...

the booster is a must.

I have an fj80 master cylinder that I picked up as an upgrade so I was going to put that in. Then may be a v6 booster

golana · « **Reply #7 on:** Mar 16, 2011, 04:23:20 PM »

Quote from: Chrstphrtptts on Mar 16, 2011, 01:16:07 PM

you think this all works the same for pre 85 front axles and ifs rear axles?

pre-85 should be the same, the part #'s for the bearings and stuff is all the same, so i dont see why it would be any different

the only difference between the year axles (iirc) is the bottom gusset. the pre-82 has no gusset, the 83/84 has the half gusset (to the leaf perch) and the 85 has the full length gusset.

and i used a IFS rear axle for the rear disc, and as far as i know, they are all the same, until you get into the 4linked rear ends and tacoma rear ends, then i dont know.

golana · « **Reply #8 on:** Mar 16, 2011, 04:26:38 PM »

Quote from: Peterbuilt84 on Mar 16, 2011, 01:22:34 PM

I have an fj80 master cylinder that I picked up as an upgrade so I was going to put that in. Then may be a v6 booster

i think the fj80 has the 1" bore cylinder, correct? that would work perfect. i used a tacoma because a) availability/cost, b) 1" bore. you will notice it alot harder to push the brake pedal though, unless you already have the dual diaphragm brake booster... i think -some- sr5 4runners came with the dual diaphragm boosters... there is a very noticable difference between the boosters. the single dia is only about 3" or so deep, and the dual dia is about 4, and is a bit bigger in diameter. ill go find my single and take a comparison picture for you guys.

but anyways haha, you will need a booster for the bigger master cylinder. you can use your stock one, but it will be harder to press on the pedal.

Peterbuilt84 · « **Reply #9 on:** Mar 16, 2011, 05:31:42 PM »

I'm pretty sure the fj80 master does have a 1 inch bore. I guess I'll just have to keep an eye out for a booster now too to go along with the calipers and rotors.

fatkidskickrocks4x4 · « **Reply #10 on:** Jan 09, 2012, 01:41:57 AM »

Great write up! I might actually atttempt this!

Michael Wollinsky · « **Reply #11 on:** Jan 09, 2012, 05:32:48 AM »

i did this i put mine on an old spindle and grinded it wit a grinder while my buddy spun it be sure to wear goggles i did and still got metal in my eye

BadnewsBob · « **Reply #12 on:** Jan 09, 2012, 06:04:34 AM »

The FJ80 master cyl has the correct valve in it for rear disc also.

frm_808 · « **Reply #13 on:** Feb 07, 2014, 01:38:07 AM »

Got the fronts done!! Now onto the rears!! Great write up sir!!

Nation · « **Reply #14 on:** Feb 07, 2014, 06:45:23 AM »

Very nice

tgmaul88 · « **Reply #15 on:** Feb 07, 2014, 09:49:51 AM »

this is how i set my brakes up in the front, all good!

helipilot77 · « **Reply #16 on:** Feb 08, 2014, 01:50:57 PM »

I have the FJ-80 master cylinder in my 87' 4runner. So that is why my pedal is stiffer. Thank you for solving my problem.

lucky7 · « **Reply #17 on:** Feb 08, 2014, 05:08:41 PM »

Doesn't this widen the front by 3"s too?

HogCanyonHopper · « **Reply #18 on:** Feb 08, 2014, 05:16:20 PM »

Quote from: lucky7 on Feb 08, 2014, 05:08:41 PM

Doesn't this widen the front by 3"s too?

did you read reply #4?

lucky7 · « **Reply #19 on:** Feb 08, 2014, 06:17:14 PM »

Gonna ask another stupid ? Why the taco discs an not the one that fit the hub

garlicgabe · « **Reply #20 on:** Feb 08, 2014, 06:32:29 PM »

bigger is better

frm_808 · « **Reply #21 on:** Feb 08, 2014, 10:00:07 PM »

Quote from: lucky7 on Feb 08, 2014, 06:17:14 PM

Gonna ask another stupid ? Why the taco discs an not the one that fit the hub

Taco is float, this way you don't have to remove the hub to replace the rotors

valon5150 · « **Reply #22 on:** Jun 18, 2014, 04:01:11 PM »

I was just trying to swap a taco booster and MC i had from an 01 v6 taco. booster is too large though, Clutch master and steering shaft are hitting it. did you use an earlier model taco or a 2.7 one?

BigMike · « **Reply #23 on:** Jun 18, 2014, 04:41:41 PM »

Good stuff

Got this thread added to our Tech from our Forum Members section on our store website!

Regards,
BigMike

valon5150 · « **Reply #24 on:** Jun 20, 2014, 04:04:11 PM »

solved my issue. massaged the lip/seem of the booster down right at clutch master and steering shaft with a hammer and it fits great now. Push rod was too short, easy to lengthen though.

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