Outer Limits 4x4 Board

I've recently finished a 3rz engine conversion into a 93model 22R 4runner, and am going thru the engineering process at the moment. It has so far failed exhaust noise and brake test.

For the brake test, it is failing due to bad brake fade after 6 or more hard stops from 80kph and above. Has anyone ever had a brake fade issue with their 4runners/surfs/hiluxes?

So far I've replace the brake pads with new Bendix 4x4 pads, but found out thats exactly what was fitted when I replaced them. I've also flushed the fluid and replaced with Dot3 brake fluid which is recommended for Toyota's. It is still suffering brake fade exactly as it was before I did any of the work.

I had it at a brake joint today to look over it, and their belief is the test is a bit harsh as they think the brakes are fine, well adjusted, and calipers in good nick and rotors still have plenty of meat on them.

The last thing I can think of is fitting slotted rotors to try to remove the built-up gasses when braking hard to help with cooling... Any ideas/recommendations would be greatly appreciated guys

Yeah I would say the brakes are getting hot quickly.

Had a Rocky and the brakes did the same thing... I can't honestly remember how it was getting so hot but after heavy braking even the wheelnuts were too hot to touch. I think I may have fixed it substantially by clearing the mud from the cooling slots so yeah, maybe slotted discs.

Have you got bigger than standard wheels on it? If so that will probably put more pressure on the dics and heating them up more.

The wheels aren't overly big, only 15x8 sunnies with 31x10.5x15's, but I suppose they are a bit bigger than standard...

The slotted rotors were quoted at $330 for both, so didn't want to have to spend it if it won't fix the prob, but if thats what it takes, then thats what I'll have to do I guess.

Yeah, i was thinking bigger tyres might be putting extra strain on the brakes but 31's on a hilux shouldnt be too bad. mine had 31's and stopped with no probs... but the chassis was cracked :(

I agree with the brake joint .. 6 stops is pretty harsh .. but thats not gunnu help you pass the test.
Are you already on vented rotors (think the 93 had em) cross drilled or slotted will definately help. See if you can get a set of alloys just for the test, slightly better heat sink\disapation. Make sure the rear brakes are 100% and doing their share of the work. Stiffer front springs to help keep the front from diving to much and adding to the weigt transfer over the front .. rig up some ducts to direct air over the rotors\brakes ... does not have to be pretty, just functional.

smaddock wrote:I've recently finished a 3rz engine conversion into a 93model 22R 4runner, and am going thru the engineering process at the moment. It has so far failed exhaust noise and brake test.

For the brake test, it is failing due to bad brake fade after 6 or more hard stops from 80kph and above. Has anyone ever had a brake fade issue with their 4runners/surfs/hiluxes?

So far I've replace the brake pads with new Bendix 4x4 pads, but found out thats exactly what was fitted when I replaced them. I've also flushed the fluid and replaced with Dot3 brake fluid which is recommended for Toyota's. It is still suffering brake fade exactly as it was before I did any of the work.

I had it at a brake joint today to look over it, and their belief is the test is a bit harsh as they think the brakes are fine, well adjusted, and calipers in good nick and rotors still have plenty of meat on them.

The last thing I can think of is fitting slotted rotors to try to remove the built-up gasses when braking hard to help with cooling... Any ideas/recommendations would be greatly appreciated guys

thats a stpuid way to test the brakes on a heavy car. most cars woudl fade if not driven around to cool the brakes before applying emergency braking one after the other.

get some pagid BLUE's or something for it.
that will fixem

bendix 4x4 or metal kings heat up to quick.
you need a pad that warms slowly and performs when hot.

Jes

Is it not vacuum loss maybe

I wouldn't bother with drilled rotors they won't get hot enough to need the holes and they run to cool for street driving. Slotted are the most you'll need on a street car. Also drilled rotors tend to crack when not allowed to cool properly if they do happen to get hot enough. bendix pads will be ok did you bead them in right or were they the CT ones Might pay if none of this is the problem fit a 80 series master cylinder if still no good then go the 80 series booster asweel

Sic Lux wrote:I wouldn't bother with drilled rotors they won't get hot enough to need the holes and they run to cool for street driving. Slotted are the most you'll need on a street car. Also drilled rotors tend to crack when not allowed to cool properly if they do happen to get hot enough. bendix pads will be ok did you bead them in right or were they the CT ones Might pay if none of this is the problem fit a 80 series master cylinder if still no good then go the 80 series booster asweel

there are two types of " holey" disks. there are those that are drilles, and those that are cast

teh drilled ones are the ones that will crack. Those cast with holes will not crack.

JEs

Cheers for that about the drilled and casted holes just seen and read a few tech articals about them cracking. Still think there a pull value for street driving

nearly all new brake pads will fade when first fitted, called green fade. one remedy is to stop hard till brakes fade then do 15 or more gentle stops with light pressure from about 60 kmh let the brakes cool before each light stop till pedal improves.

If there bendix CT pads fitted there supposed to give good pedal feel from first applacation and require no beding in. I give them a little bed in when i fit them at work and i say it gives them a better pedal feel.

Nah, the pads are Bendix 4x4 pads, which from what a few people have told me, are an almost identical compound to their Bendix Advance pads, which I've used in the past on my commodore and loved the feel and lack of brake fade.
The ones I got have a "Titanium Stripe" that means you don't have to bed them in, but they've been bedded in anyway, can't hurt. I'm gonna drive them for a few hundred k's, then give them a proper test to let them complete bed in. Will see how they go.

smaddock wrote:Nah, the pads are Bendix 4x4 pads, which from what a few people have told me, are an almost identical compound to their Bendix Advance pads, which I've used in the past on my commodore and loved the feel and lack of brake fade.
The ones I got have a "Titanium Stripe" that means you don't have to bed them in, but they've been bedded in anyway, can't hurt. I'm gonna drive them for a few hundred k's, then give them a proper test to let them complete bed in. Will see how they go.

check the brake proportioning valves in the rear if you have raised the 4runner then it needs to be adjusted the same hight as the 4runner if u raised it 2in then turn the nut 2in up that what my friend has done u might have to extend the threaded part were u adjust the nut