67Rocket

After bench bleeding the master cylinder which took hours, I installed it along with a new booster. Car has absolutely no brakes and when I press the brake pedal in the engine starts to run rough which sounds like a vacuum leak. The push rod has been adjusted in and out and makes no difference. The brake lines were capped off as soon they were removed from the master cylinder and only a few drops were lost so I don't see how air in the lines would be the cause of no brakes at all. The booster and master cylinder were purchased from OPGI which may be the problem. I reinstalled the old booster and master cylinder and brakes work fine. I wanted a nice looking brake booster was the reason for the change. Any help would be appreciated.

joe_padavano

Bleed the entire brake system FIRST, then get back to us.

67Rocket

Thanks Joe, when I put the original booster and master cylinder back on
and drove the car 50 miles the brakes work fine. Guess I will have to get use to a crappy looking booster or try another vendor. Any suggestions? Thanks again.

lemoldsnut

New does not mean good it just means new. You say no brakes. What does that mean? No firmness to the pedal? Pedal goes to the floor? Firm pedal but not braking?

Bench bleeding a master takes only a few minutes. Did you use a set of lines back to the reservoir when bench bleeding it? If not then maybe you never did get it bleed.

It almost sounds like two issues. Master not bleed and booster has a hole in the diaphram.

Just my 2 cents

Larry

m371961

My guess is the wrong or missing push rod between the master and booster. If the booster is bad it would still brake and bleed. Or the new master is bad.
I also do not understand bench bleeding of the master taking hours as you mentioned. That should have only been minutes.

67Rocket

I was surprised at how long it took to bleed the master cylinder and yes I did use the two lines back to the reservoir. The fact that the engine idles rough when I push on the brake pedal makes me think there is something wrong with the booster. The pedal never did get real firm and goes all the way to the floor with no brake. I am returning the unit to OPGI, Has anyone else had issues like this? Thanks

joe_padavano

Pedal going to the floor has nothing to do with the booster. If the booster were bad, you'd have no boost and the pedal would be harder to press. The rough idle is a different issue and may be booster related. Pedal to the floor is either an incorrect pushrod between the booster and M/C or air in the system.