Hi all. Newbie question. I have a 1970 Fj40 that I have been slowly restoring. I will be using axels from a 1977 fj that I am currently rebuilding. I also was planning on using a master cylinder and brake booster from a FJ60 set up with discs in the front and drums in the rear. My question is where do I hook my booster vacuum hose to and does it need a one way valve incorporated into the vacuum set up (currently a single circuit setup with no booster). I have searched a bunch of forums but haven't found anything. I would appreciate any advice. Thanks in advance!
Brake booster vacuum question!
- Thread starter Jledoux
- Start date
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Yes, you should absolutely use a check valve. The idea here is that when you shut off (or kill) the engine and lose your vacuum source, you still have 1-2 pumps of the brake pedal assisted. Very helpful on hills! On my 71, I have a nipple on the intake manifold for the brake booster. I'm guessing your 70 does not have this since it didn't come from the factory with a brake booster. 3 options as I see it. You could tee into your PCV valve hose that attaches to the base of the carb. You could drill and tap a hole into the stock intake manifold and screw in a hose barb. Or, you could source an intake manifold from a later cruiser with a brake booster nipple to swap in.
I'd drill and tap a hose barb for it. With brakes it's best to not have a bunch of t's and fittings. Best to have a single hose with two clamps for the least failure points. The 60-series booster should have the check valve built into it where the hose connects. If you were to go with a minitruck booster, the check valve is an inline, separate piece.
Are you using vacuum actuated 4wd? There should be a barb for that
- Thread starter
- #5
I am using a fj60 booster. And it is a vacuum actuated 4wd. The barb coming off the booster is just a metal elbow. It doesn't have the plastic piece that fits into a grommet that you normally see on a typical booster. That's why I wasn't sure about the one way valve. There is a spot on my intake manifold between the carburetor and the fire wall that has a spot where it looks like I could go. There is a "bolt" there that looks like I could take out and use as a vacuum port but I'm not sure what I would use as the barb for the hose to attach to.
I think the hose to the booster is 3/8", but measure to be sure. Go to your local hardware store and pick up a 3/8" barb x male pipe thread brass fitting. Also buy the associated tap to match the brass fitting (most likely a pipe thread). Drill and tap your manifold. Screw in the fitting and you're good to go.
