4 runner brake booster results

[AKFJ80]

There are other threads in here about upgrading the factory brakes on the 60 series. However none of them were very succinct or to the point on how well it actually improved stopping.

I have an 88 with factory rear drums and I *think* 4 runner front calipers but I honestly am not sure.

I went to Napa and ordered a brake booster from a 94 4 Runner. The old Booster put up a good fight coming out. You do not need to disconnect brake lines from the master, just unbolt it and carefully lay aside.

The 4 runner booster would not mount without inverting the booster so the vacuum port is now on the bottom (about the 5'O clock position) so longer booster hose was used.

Inverting the booster does nothing regarding performance of the diaphragm.

I am running 37" goodyear MTR's and full armor, drawers, rack winch etc... and before braking was a bit scary to say the least. You really had to mash the pedal to make anything wake up and stop the beast.

Now just a slight touch of the pedal and you get that brake grab feel off the bat and the truck comes to a stop as it should. I have no actual data on stopping distances before and after but seat of the pants this is an absolute worthwhile improvement that I highly recommend to my fellow 60 series guys with marginal braking.

I believe the 4 runner booster is approx 1" larger diameter which may attribute to the added vacuum assist to the pedal. I did not have any fitment issues with this larger diameter drum.

Easily the simplest and one of the BEST mods I have done to my cruiser for every day drivability.

 

[maat]

its good to hav a follow up on this type of thing!!

 

[MikeTheGreat84]

There are other threads in here about upgrading the factory brakes on the 60 series. However none of them were very succinct or to the point on how well it actually improved stopping.

I have an 88 with factory rear drums and I *think* 4 runner front calipers but I honestly am not sure.

I went to Napa and ordered a brake booster from a 94 4 Runner. The old Booster put up a good fight coming out. You do not need to disconnect brake lines from the master, just unbolt it and carefully lay aside.

The 4 runner booster would not mount without inverting the booster so the vacuum port is now on the bottom (about the 5'O clock position) so longer booster hose was used.

Inverting the booster does nothing regarding performance of the diaphragm.

I am running 37" goodyear MTR's and full armor, drawers, rack winch etc... and before braking was a bit scary to say the least. You really had to mash the pedal to make anything wake up and stop the beast.

Now just a slight touch of the pedal and you get that brake grab feel off the bat and the truck comes to a stop as it should. I have no actual data on stopping distances before and after but seat of the pants this is an absolute worthwhile improvement that I highly recommend to my fellow 60 series guys with marginal braking.

I believe the 4 runner booster is approx 1" larger diameter which may attribute to the added vacuum assist to the pedal. I did not have any fitment issues with this larger diameter drum.

Easily the simplest and one of the BEST mods I have done to my cruiser for every day drivability.

How much was the booster if you don't mind my asking.

 

[AKFJ80]

I don't mind at all. I believe it was 184 with 50 dollar core charge.

I was naughty and returned my 60 booster as the "core". I am sure the toyota Gods of remanufacturing will be okay with it.

I must have gotten my part numbers mixed up

Kinda spendy but It is much more worth while than just a caliper upgrade that did not seem to yield any better results.

 

[Devils Paw 80]

Sounds like a great upgrade. What made you go with a new booster, rather than swapping in a 4runner MC? That's been done more often, maybe because it's cheaper.

 

[Dieseler]

What no pictures.
Did you have to adjust the brake pedal shaft or was it just a plug and play.
Why did you decide to go with a 94 and not earlier years.

 

[Ozone]

Man this topic really hits home as I'm still having issues with my brakes. I have replaced all hardware (pads,rotors, shoe and drums, and all soft lines) also a new MC. I'm still getting poor brake performance.

I've been shopping around for a new brake booster and holy crap are they $$$. 4 bills for a rebuilt and a grand from Toyota for a new one.

Can I swap the 4 Runner booster and use the new '89 LC MC and front brake hardware?

This would be music to my ears.

I stopped in at Stevinson Toyota ( Golden, CO) this morning and I'm taking running my 62 down there this afternoon to have them vacuum bleed my lines as I'm wanting to confirm it is the booster before this significant investment.

 

[MANUCHAO]

you'll be even more amazed if you ran a T100 M/C and the rear axle of an FZJ80 with disk brakes along with that new booster....

 

[Spook50]

you'll be even more amazed if you ran a T100 M/C and the rear axle of an FZJ80 with disk brakes along with that new booster....

I think that's the best braking combination for a 60/62. 4Runner calipers, 1" bore master, larger booster, and FZJ80 rear end with the discs.

That'll be my final setup once I get the 80 rear

Wishing I hadn't gotten rid of the LSPV though because I'd like to see how well it would work with an 80 rear end in place if it could be dialed in.

 

[Devils Paw 80]

..

Can I swap the 4 Runner booster and use the new '89 LC MC and front brake hardware?

Yes you can.

 

[Elbert]

while its obvious....I only got around to replacing all my brake hoses a month or two ago....I just had forgotten about that. This should be a number 1 to do item on any vehicle this old, I may look to get a T100 booster at some point.

Just replacing the hold hose with new (in my cans naps stuff), made big improvement...Yea I know its the dumb stuff that bites you in the @SS

 

[AKFJ80]

Sorry guys I have been under the truck all day fixing wiring and such! I only get updates once a day.

Sounds like a great upgrade. What made you go with a new booster, rather than swapping in a 4runner MC? That's been done more often, maybe because it's cheaper.

I have done the MC swap before but on mini trucks and it honestly did not seem to yield much performance gain with the exception of correction proportionate fluid displacement with larger brakes etc....

I figured the larger diaphragm would give more mechanical assist.

What no pictures.
Did you have to adjust the brake pedal shaft or was it just a plug and play.
Why did you decide to go with a 94 and not earlier years.

I measured the old turnbuckle on the old booster and "dry rigged" the new booster to match. I ensured the brake light switch disengaged etc... WHich reminds me that if you take your time on this make sure you are aware your brake lights will be on when the brake pedal is discod from the booster.

I will get some pics up tomorrow sorry, I know these threads are lame without them, just a boring old booster though! haha

Man this topic really hits home as I'm still having issues with my brakes. I have replaced all hardware (pads,rotors, shoe and drums, and all soft lines) also a new MC. I'm still getting poor brake performance.

I've been shopping around for a new brake booster and holy crap are they $$$. 4 bills for a rebuilt and a grand from Toyota for a new one.

Can I swap the 4 Runner booster and use the new '89 LC MC and front brake hardware?

This would be music to my ears.

I stopped in at Stevinson Toyota ( Golden, CO) this morning and I'm taking running my 62 down there this afternoon to have them vacuum bleed my lines as I'm wanting to confirm it is the booster before this significant investment.

Yes this is a direct swap with the exception of having to invert the Booster which affects nothing. Some may argue that if your Master leaks out into your Booster your engine could suck up the fluid and cause issues...but I think you would have MUCH bigger issues before worrying about that sort of event.

you'll be even more amazed if you ran a T100 M/C and the rear axle of an FZJ80 with disk brakes along with that new booster....

Nice, thanks for the heads up! I almost went with an 80 series axle but after the myriad of things I have done to this rig I am gonna give the SF axle a chance for a while. Just put in some 5.29's and a Grizzly locker so well see how she does!

 

[AKFJ80]

What no pictures.
Did you have to adjust the brake pedal shaft or was it just a plug and play.
Why did you decide to go with a 94 and not earlier years.

I did have to Adjust but simply to match how the old turnbuckle was. I measured and counted threads but ultimately had to adjust once installed as the new one had a bit more extension on the plunger than the old 60 series booster.

I chose the 94 based off a random post I found by a member on this forum. I believe several other years will work, but he mentioned ABS and other variables involved with the others that may confuse parts counter guys. The 94 is a sure thing so I just went with it.

This random post was helpful, as he stated it cured his poor brake issues but there was no real followup about whether his old booster was defective or not.

Napa seemed the have the best price I found, by several hundred dollars in some instances.

 

[ntsqd]

As I've said in the past, going to a larger bore M/C actually reduces your leverage in the brake system. It firms up the pedal feel and shortens the pedal travel, both of which are a plus for most drivers, but it actually reduces how effective the system is because to get the same braking as with the smaller M/C you now have to push harder. Starting here are the leverage ratios: https://forum.ih8mud.com/showpost.php?p=6458144&postcount=64 if the seeing the numbers helps put it in perspective.

What none of that math can account for is the effect of the booster. A larger diaphragm can increase the force on the M/C piston for the same operator's pedal effort because of the greater surface area of the larger booster OD. I say "can" because there is a valve inside of vacuum boosters that controls the amount of boost vs. how far the pedal is pushed. The booster vs. displacement curve is something that the OE's tune to the expected use(s) of the vehicle. So the booster on the pedestrian version of the car and the booster on the hot rod version may look exactly the same, but they can have totally different valving to make the brakes behave appropriately for those different uses.

Having done the 4rnnr caliper only swap, mostly out of curiosity, I would do the booster swap as the very first upgrade. Then if you need/want more look at the hydraulics. The hydraulics are a delicate balance, you don't have to change any bore size by very much to end up with a system that is totally unsuitable to drive.

 

[AKFJ80]

Actually Ntsqd I have read many of your posts these pasts years regarding fluid dynamics etc and it is very helpful explaining the affects of bore size and fluid displacement, perceived forces vs actual forces etc..

Thanks for taking the time to spell all of that stuff out!

 

[Bowling4$]

I did the same brake booster swap in mine only I can't remember what year of 4 Runner I took the booster from. I just wondered around the junk yard until I found one that looked like it would fit. Anyway it appears to be failing after 4 years so this info is very helpful! Is the rear axle on an 80 the same width as the 62?

 

[MANUCHAO]

No, it is not the same width.. it is about 5" wider....

 

[Spook50]

No, it is not the same width.. it is about 5" wider....

I thought I had seen in the past that it's 4" wider.

 

[Bomar]

It have been thinking about this and now I will do it. b/c I have done everything but this to make my brakes better. I wanted them to work like my 94' Runner and everything is the same in my system except the booster.

 

[MANUCHAO]

I thought I had seen in the past that it's 4" wider.

I'm old n forget, but you probably right..!!