Installed on my 1959 gmc 1/2 ton for about 5 years. The pedal does not always return to the top. This is the under floor booster with combination valve on a disc/disc truck.
When I start the truck, I can see the pedal move about 1/2 way down, and then slowly come back up. Brake travel seems a bit much. I noticed a small drip of fluid coming from the booster last week.
So do I have a bad MC? (spent several hours bleeding the brakes today, the front reservoir was dry.)
A bad vacuum booster?
Or something else I haven't considered?
