Brake master & booster options on a '72 40 (1 Viewer)

[Cleg]

Putting my '72 FJ40 back together and hate to bolt anything questionable back onto it. It has been converted to disk brakes on the front axle. I suspect the brake booster wasn't functioning completely and the bore of the master cylinder is badly pitted although it seemed to still be working.

Are any of the master cylinders from different years interchangeable?
'71-'75, 1/'75-8/'75, '76-'80....
Can anyone offer 1st hand experience with using a brake booster + master cylinder combo from something else that will not run me $800?
I saw somewhere in this forum that an 88 Toyota pickup booster might fit.
Would that fit with it's own master cylinder or with the original?

Any help is greatly appreciated.
Thanks

 

[DSRTRDR]

what disk brake conversion do you have ?

OEM master cylinders that came with original drum brakes have residual valves in them specific for drums - when a conversion is done, those need to be removed for the respective axle that was converted - and then, you may need a proportioning valve to adjust the brake line pressure so that the front brakes lock first

how do you know your original booster or master are dysfunctional ?

 

[sgirt]

I went with a 7" dual diaphragm booster and 1 7/8 master from Summit. I did have to modify the firewall a little to get it to bolt up. I have disks all around and it stops on a dime.

 

[Cleg]

Thank you SGIRT for the answer. What would I look for at Summit, part # or description or vehicle to fit?
DSRTRDR - "what brake conversion do you have" Not sure, it was on the rig when I bought it but I can figure out the area of the pistons if that helps. I was told the non '72 parts were from a '78. If that is the case can I use a '76-'80 brake master (w/o pressure switches) ? All original parts seem to be in the '72 brake master. I assume you were referring to the internal valves behind each outlet port. They are in place. The hydraulic lines go directly to their axles with no apparent proportioning valve. "How do I know the booster is bad" I don't, but it seemed to be doing a poor job of holding vacuum and it is 40 years old. Same with the Brake Master. Working but pitted. My goal with this project has been to build the vehicle to a point where I could put the wrenches away and let a non-mechanic drive it on a weekend trip without getting stranded somewhere. If the first cylinder-booster lasted 40 years, I want to build it so at least that system could go another 40. So on the critical stuff I'm trying to go with new parts.

 

[Josie'sLandCruiser]

Hi All:

Hate to say it, but gotta: try the search function first! Lots has been posted here on MUD about brake boosters and master cylinders.

That out of the way, many Toyota brake parts are interchangeable between Land Cruisers and 4wd mini-trucks.

My '74 FJ40 has a '78 front axle housing running '83 outer parts (discs, Birfields, etc.) The brake calipers are from a 1991-95 V-6 4Runner. The master cylinder is from a 1990 4wd mini-truck, while the brake booster is from a '85 4wd mini-truck.

All these parts bolted-up, with just some minor fitting adjustments.

Good luck!

Alan

Putting my '72 FJ40 back together and hate to bolt anything questionable back onto it. It has been converted to disk brakes on the front axle. I suspect the brake booster wasn't functioning completely and the bore of the master cylinder is badly pitted although it seemed to still be working.

Are any of the master cylinders from different years interchangeable?
'71-'75, 1/'75-8/'75, '76-'80....
Can anyone offer 1st hand experience with using a brake booster + master cylinder combo from something else that will not run me $800?
I saw somewhere in this forum that an 88 Toyota pickup booster might fit.
Would that fit with it's own master cylinder or with the original?

Any help is greatly appreciated.
Thanks

 

[Cleg]

Brake options

Thanks for the providing the specific answer complete with years & models. It gives me what I need to go get some hardware. I apologize if all of this has been covered before. It seemed like it should be a common issue but I couldn't find in anywhere under FAQs.
Now that the master cylinder & booster are all apart on the bench I can see it all needs to be replaced. If you were buying the 2 pieces new or rebuilt what would be the preferred setup?

 

[srgould41]

Sure you don't mean 1 1/8"? I don't think they make 1 7/8".

I have the 1 1/8" GM master with a 9" dual diaphragm booster and it's OK, but not perfect.

I went with a 7" dual diaphragm booster and 1 7/8 master from Summit. I did have to modify the firewall a little to get it to bolt up. I have disks all around and it stops on a dime.

 

[FixedIt]

I converted front knuckles to discs, still drums in back though all dialed in and went with a NAPA-rebuilt 4Runner booster and new NAPA 4Runner MC on my 1970. All fit ok, little modification to some metal under the hood but no biggie.

Stops fantastic, but needed a prop valve for rear. Overall price was decent.

 

[Josie'sLandCruiser]

Hi All:

Cleg, it really boils down to what you are willing to pay.

The new OE Toyota parts are obviously top notch, but re-built parts can be quality too.

Regards,

Alan

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If you were buying the 2 pieces new or rebuilt what would be the preferred setup?