Carb versus Brake Master Cylinder & Booster. (1 Viewer)

[Ralph3]

I know this has been answered, but I cannot find it. A 69 cruiser has a 4 wheel disc brake upgrade with a booster and master cylinder. The booster is extended beyond the support on the firewall. The new carb has a secondary that competes for the same space as the end of the master. The answer for the seller was to remove the secondary! I don't want to cripple the carb. I can't find a carb that will work with the booster/master combo, which I also don't want to do without. Considering other carb options. Longer term, I was going to go with a TBI, Holley or Howell or ?. I'm not trying to turn the '74 F.5 tractor motor with a 2F head into a hot rod, just get the best out of the engine rebuild without sacrificing braking. Thoughts, anyone? TIA.

 

[Skreddy]

My 1970 had the F and a bracket to run the booster beyond the firewall rib. To run this with the stock mechanical secondary Aisin carb, they removed the choke bleed diaphragm. I tried mocking up a booster when I went to the Holley sniper and there just wasn’t a way that I could find using a spacer off the firewall and keeping the rib for the booster. The only way I know of on the early rigs is to cut the firewall rib so the booster sits closer to the firewall. (Still need the adapter to the modern bolt pattern if I remember right?). That was with the mechanical secondary. I think it’s worse with the vacuum secondary carbs?

 

[Ralph3]

My 1970 had the F and a bracket to run the booster beyond the firewall rib. To run this with the stock mechanical secondary Aisin carb, they removed the choke bleed diaphragm. I tried mocking up a booster when I went to the Holley sniper and there just wasn’t a way that I could find using a spacer off the firewall and keeping the rib for the booster. The only way I know of on the early rigs is to cut the firewall rib so the booster sits closer to the firewall. (Still need the adapter to the modern bolt pattern if I remember right?). That was with the mechanical secondary. I think it’s worse with the vacuum secondary carbs?

Yeah, the replacement carb I bought has the vacuum secondary. Well, that seems to eliminate the Holley as a solution. If I knew the pitfalls of removing the rib.... but, some Toyota Engineer decided it needed to be there...... who am I ....? Thanks!

 

[Skreddy]

Lots of people remove the rib. I chose not to because I didn’t want to modify the body and I don’t mind manual brakes.

 

[bikersmurf]

An 80 series master is shorter…

"Shorter" 80 master and booster install in 40

New 40 boosters aren't available anymore. So I found a booster from a diesel 80 series to replace my tired one. Little did I know how tired my 25 year old 40 master had got. Length of 80 master. Length of 80 master/booster from firewall. Brakelines needed to moved a bit so they don't get...

forum.ih8mud.com

Don’t know if it’s enough shorter, but my $.02

 

[65swb45]

Which manifold set are you running? The F manifold puts the plenum 1” closer to the head than the 2F.