[simpletoy]

stock braking system on 80 toy ( to my knowledge) except extended brake lines.

when i pump the brakes(booster working) my rpm's drop, but only if i pump repeatedly.
is this normal for a toy?

my braking system has issues, that should also probably be explained...

when the brake booster is hooked up my pedel has no resistance at all, and the pedel goes about halfway to the floor then stops and won't go anymore. i can lock them up if i slam them on but when slowing down gradually i run out of braking power real fast (pedel won't go down further and im still moving).

when the brake booster is NOT hooked up the pedal functions normal except for the amount of force i have to put on it, but thats expected.

has anyone else experienced this with their power brakes? a fix or way to give my pedal some resistance?

 

[JamisonWorkshop]

On the RPM thing I wouldnt mind knowing. but I believe it is just all the vacuum pressure from the engine. My RPM's fluctuate with the brakes in it goes down, push the clutch in and they go up, and the fan if i turn it on they go down. Ganted it is only minor.
Like 200 RPM's if.

 

[OffroadRunner]

Makes sense about RPM's especially on a Carb. You are changing intake vacuum everytime you push the brake pedal.

Jamison when you push in the clutch you are lessoning the amount of rotational mass. Your RPM will rise slightly and then return to normal.

 

[4bangr]

I thought the brake booster had a one way valve to keep this phenomina from happing. Your booster could have a leak, because this shouldn't happen

 

[simpletoy]

is there a way to check the booster for leaks?
i know my master cylinder doesn't leak.

 

[OffroadRunner]

Unhook the booster vac hose and put a vacuum gauge on the fitting where the hose was. should hold vacuum

 

[zags]

There is a check valve in line in the vacuum hose to the booster. It is clipped to the firewall on '84 and up, not sure if its the same on an '80. It is probably bad. You should be able to suck air through it from the engine side, but not the booster side.