I need to fix my brakes (4 Viewers)

[6f40j9]

Early on, I threw a disc brake front end under this thing. It had already been converted. I don’t know the kit, or year but stainless lines, wilwood calipers.

I installed a new rock auto dual reservoir master cylinder (I think for a mid 80s Toyota pickup) and bench bled it first. No booster, JTO adapter.

I made some new brake lines and installed a proportioning valve so the rears would quit locking up.

I adjusted the rear brakes.

It was always a 2 pump setup to get them to work.

Last year I lost all fluid in the rear, and the fronts were worthless.

I replaced (2) rear cylinders and (2) brake lines (they had rusted out).

Bled, adjusted, bled, adjusted, etc…

Still a throw away first pump.

There’s no leaks, fluid wise that I can see.

When I jack up the front and press the brakes, they work (after one pump) so not sure why they didn’t when the rears failed.

I’d love to simplify the system if I could, as the dual reservoir get in the way of the vacuum stuff on the carb (another nightmare subject) so it got removed.

If I go to an 80 master, do I still need a proportioning valve?

 

[Shark56]

I run the 80 master on my 69 converted to 78 front axle, drum rear. No booster. I do run a proportioning valve.
Possibly need to adjust your rod going into the master cylinder a little if you need one pump to get the brakes to work. That is assuming you are sure you have no air in the system.

 

[pb4ugo]

It could be a rod adjustment. Typically, If you have to pump the brakes you likely have air in the system or the m/c isn't large enuff.