I have a 1970 F600, 330 V8/ 5 speed/ 2 Speed rear end


Brake system has the single brake line, single chamber style setup.

When the brakes are applied, they work, etc but it almost kills the engine out.

Any ideas?

 

Do you have a brake booster on the dash as commonly seen on cars and pickups?

Or do you have a hydro-vac booster on the frame under the drivers seat?

In either case, check all the lines to the booster.

You may have a booster problem that causes a giant vacuum leak.

If you pull the lines and plug them, you will have no power brakes but at least you could let it roll at 5 mph with clear space ahead of you, and apply the brakes. With no vacuum connection, if it dies then it might be your carb fuel level.

 

Was there not some kind of check valve thing maybe in front of the firewall in the master cylinder area. One of the lines to it went to manifold vacuum. Or as stated a bad leak?

 

Ruptured booster diaphragm.....

 

So to bring this thread up to speed:

-Replaced the spaghetti bowl worth of T fittings and capped off vacuum lines with all fresh vacuum lines WITH clamps (half the clamps were missing previously)

Now the truck stops a smidge better but still has the same issue of the engine stuttering until it kills out with the brakes 100% applied (takes 3-5 seconds of HARD pedal mashing but it will definitely kill the engine out)

I did notice that with all new vacuum hoses and whatnot it takes a little longer for the stuttering to actually start taking effect.

I'm now to the point of replacing the Brake Booster but can't seem to find many replacements in stock; and at that they seem to have specific part numbers (my booster is pretty crusty looking