upgraded? brakes

[jblueridge]

I finally got the 80-series brake booster rod extension I needed and I tried out the upgraded brake system in my 74. I have at least two problems.

The new dual-diaphragm brake booster came with a grommet but no vacuum hose fitting. I bought a generic check-valve that fits but now I have the original check-valve in the vacuum reservoir can and this new plastic thing; what should I be using?

Second I simply spliced the sensor on the new 80-series brake master cylinder lid into place of the original. The dash brake light is on now. Was my wiring idea correct and something else is messed up?

Any help would be greatly appreciated.

 

[ozcrusier]

It's hard to guess your problem with out checking everything but it sounds like the aftermarket valve could be the wrong type as one will only pull air or fumes and the other will only push as there one way valves maybe swap them around but unsure of the plumbing. The multimeter is a great tool for trouble shooting wiring and can be brought for 10 bucks but invest in a good unit to last.

 

[jblueridge]

I think the cheap check valve does work the right direction. With the engine running the pedal went down some. I pulled that valve out with the engine on and there was a lot of air being pulled. When connected, felt like the vacuum was too much and the pedal was not returning by spring force.

The new sensor for the master cykinder cap did not have different wire colors for positive, negative. I just took my best guess and soldered the wires.

 

[ozcrusier]

I just brought a 4 runner booster and Aisin master-cylinder for my hj75 let you know how it go's on install with stock calipers and drums.

 

[jblueridge]

I got the dash brake light to go out. I had to fill the MC reservoir all the way up to Max.

I adjusted and readjusted the push rod because there was zero free play. That seems sorted out now also.

I think I need to re-bleed because if I keep my foot on the pedal with the engine running, the pedal will slowly go down.

Also, if I pump the pedal, I get one good jolt of the brakes, then the second pump feels like there is little or no vacuum booster.
maybe this is related to having two check-valves?