Early FJ40 power brake upgrade & clearance issues

Steve Abbott

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I'm starting to get very close to paint on my '65 FJ40 project and I want to weld up the old booster holes and get the new ones drilled out before the tub goes to paint. I'm trying to figure out potential clearance issues for a power brake upgrade. Normally it would be easy to measure everything, but my truck is in pieces so it is very difficult to figure out clearances. On top of that, my truck is a bit of a frankenstein: '65 tub and frame, '78 2F engine/drivetrain, long runner intake, Sniper FI (which I haven't purchased yet). The previous owner has already cut the reinforcing rib on the firewall for a jack-legged GM power brake system that was used with a SBC conversion that I have since done away with. In short, I'm looking for a booster/master cylinder setup that is compact in total length and booster diameter since I have no way to measure final clearances at this point. I have read TONS of threads on power brake upgrades and carb, clutch master cylinder & rib clearance seem to be the big factors, in addition to actuator rod issues. This thread about doing a booster upgrade is pretty close to my setup. The only question I would have is how much bigger is the Sniper footprint vs. a carb? In the previously mentioned thread, @wngrog used a CityRacer @Racer65 booster and an ADVICS master cylinder which looked fairly compact. I checked the CityRacer site but it is currently down so I can't get any info on the size of the booster right now. The other option I'm looking at is a mini-truck booster from early 90's. The mini-truck booster appears small in diameter and sits tight to the firewall. I'm not sure what my options are for a short mc that fits that booster. Any input regarding a compact booster/mc combo would be greatly appreciated!

Steve
 

Steve Abbott

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Joined
Sep 9, 2017
Messages
68
Location
Bloomington, Indiana
You can fit that setup from city racer and a sniper. No issues. Plenty of room. The only time you run into issues of room is if you use the JTOitfitter adapter. Sounds like that’s not the case for you.
Good to know! Yeah, I wanted to stay away from spacers since that just adds to the clearance issue. I'll just drill out new holes and go from there. Thanks!
 

Steve Abbott

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Joined
Sep 9, 2017
Messages
68
Location
Bloomington, Indiana
You can fit that setup from city racer and a sniper. No issues. Plenty of room. The only time you run into issues of room is if you use the JTOitfitter adapter. Sounds like that’s not the case for you.
Oh, I meant to ask if you had rear disc brakes when you went with that booster. I'm just running front discs for now but may add rear discs at sometime in the future. Any issues you know of running this booster with just front discs?
 
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On my '66 I used '82 mini parts. Booster, M/C, firewall spacer, etc.
Welded re-enforcing plate to firewall.
Cut vertical firewall brace for M/C clearance. Used '76 FJ40 prop valve for rear in line at M/C.
'66 brake pedal sits closer to the floor than disc brake versions. After screwing with that for a while, ended up cutting brake pedal arm and changing pedal height from firewall about an inch (closer to driver, not 'up' from floor).

This was done converting to all disc brakes. Mini(non vented) in front, GM (Monte Carlo?) in rear.
 

Steve Abbott

SILVER Star
Joined
Sep 9, 2017
Messages
68
Location
Bloomington, Indiana
On my '66 I used '82 mini parts. Booster, M/C, firewall spacer, etc.
Welded re-enforcing plate to firewall.
Cut vertical firewall brace for M/C clearance. Used '76 FJ40 prop valve for rear in line at M/C.
'66 brake pedal sits closer to the floor than disc brake versions. After screwing with that for a while, ended up cutting brake pedal arm and changing pedal height from firewall about an inch (closer to driver, not 'up' from floor).

This was done converting to all disc brakes. Mini(non vented) in front, GM (Monte Carlo?) in rear.

What did your re-enforcing plate entail? I figure I'll have to do something as well. Thanks.
 
Joined
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Messages
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There was a thin 'spacer' that came off the donor truck. Had a very qualified welder friend weld it for me. Weld penetrated through firewall to pedal bracket inside under dash. Sorry no pix, was over 20 years ago.
 

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