FZJ80 Brake Booster in a BJ74 (1 Viewer)

[MyCruiserisaHogBeast]

I confirmed what everyone was saying about putting a US spec 80 series booster into a 70 series: short answer: it fits!

Long answer-
I didn’t want to deal with bleeding everything, so I managed to remove the booster while keeping my brake cylinder and power steering reservoir sealed. After making sure the back of my master was dry I carefully pushed it out of the way making sure not to pinch the brake lines. I ended up removing the power steering reservoir and fuel water separator bracket to give me room to work, but everything stayed sealed.

I used a Duralast 88808 from Autozone which is for a ‘93 FZJ80. Earlier model boosters were not available so I took the plunge, it looked like what I needed and it was all I could get quickly and I didn’t want to spend a ton of money in case it didn’t fit, middle of the road higher quality options weren’t readily available, so this is what I had. On the booster removed I measured the brake pedal rod and created an extension. It was over an inch short. I had one of the guys in the shop make a coupler out of some M10 1.25 nuts, I couldn’t find a coupler. I cut the head off of a matching bolt and threaded it together.

Someone had mentioned me to make sure to check the output length and I’m glad I did. Adjusted it to match the old one.

Its a tight squeeze but it fits. I rerouted the vacuum hose from the manifold that lives under the booster under the body and around to the fitting, which is on the right hand side. This is the only way the booster installed, the mating surface is not symmetrical and only goes in one way. It’s about 1/2” from the water separator lines, any longer and relocation would be required.

If the booster lasts, I’ll wait until the mater cylinder dies and I’ll upgrade the booster to a high quality Toyota one and I’ll upgrade the master to a 91-92 FJ80 master cylinder. The roads are slick and I haven’t been able to actually test and see if there’s any difference in stopping power, but the factory system stopped really well and I had no complaints, so I’m sure it’s really good.

 

[Will Van]

I used a Duralast 88808 (booster) from Autozone which is for a ‘93 FZJ80...I’ll wait until the mater cylinder dies and I’ll upgrade the booster to a high quality Toyota one and I’ll upgrade the master to a 91-92 FJ80 master cylinder.

Great write-up.

Why use a later model FZJ80 '93 booster and an earlier model FJ80 '91-'92 master cylinder? It looks like the earlier model FJ80 boosters have the vacuum port on the correct side. But the late-model was the only 80-series booster available when you were working on this project?

Is there an advantage to using an early-model FJ80 master cylinder as opposed to late-model FZJ80 master cylinder?

Edit: I may answer my own question - It looks like the late-model FJZ80 master cylinders have a port for ABS (which we don't need on a 70 series). And a high-quality early-model FJ80 booster is NLA.

 

[OGBeno]

Just get the correct 70 booster and use whatever bore size MC you want from a non-ABS setup truck platform vehicle. Doesn’t have to be a Land Cruiser.

 

[MyCruiserisaHogBeast]

Great write-up.

Why use a later model FZJ80 '93 booster and an earlier model FJ80 '91-'92 master cylinder? It looks like the earlier model FJ80 boosters have the vacuum port on the correct side. But the late-model was the only 80-series booster available when you were working on this project?

Is there an advantage to using an early-model FJ80 master cylinder as opposed to late-model FZJ80 master cylinder?

Edit: I may answer my own question - It looks like the late-model FJZ80 master cylinders have a port for ABS (which we don't need on a 70 series). And a high-quality early-model FJ80 booster is NLA.

Thanks!

The main reason why I used this is because I'm a masochist and daily drive my BJ74 and I needed to source a quick replacement. Yes, Autozone had this on hand, I checked the bolt patterns and everything matched. At the time no one had a factory booster on hand so I needed to get it back on the road. It's also a dual diaphragm booster and gave me a little extra stopping power. I've used 80 series masters on early trucks with adapters and they have more oomph, so when this goes out that's what I'll do. It'll require some work on the brake lines and I figure if this setup ain't broke, don't fix it. You're correct, later model has ABS.

The current set up works really well. A factory 70 series booster would have obviously done the trick too, and that's what I would have done if it had been available at the time. I put new front rotors and pads on and adjusted the rears, it'll lock of my 35s without hesitation and didn't require a ton of modification.