I've got a brand new booster/Master.I still have no pressure on my pedal.This is on an 82 CE.Nothing leaks that we can find.Is there some kind of rear adjustment that we are overlooking?This whole ordeal strated with a leaking MC and since this is bing done under warrenty I'm not going to take it home and work on it.The shop guys are baffeled at why after replacing the booster and MC, blead the system and still the pedal goes all the way to the floor.I've got a shop manual that they want to look at but I was hopeing someone on here has been where I am right now.Thanks.

does your vette have a bigger cam in it ,if so maybe it"s not getting enough vacume for the booster

I can think of two things....
1) The master is still bad.
2) It is the wrong master.

# 1 is self explainatory(I hope)
# 2 is just a w.a.g. There are two different pistons for the masters, depending on year model. One has a deep well for the pedal pushrod, and the other has a shallow well for the pushrod. You can't put a shallow master on a deep pedal, but...you can put a deep well master on a shallow pedal.
If you do this, the pedal will never fully stroke the piston in the master, so it will never pump up correctly. Like I said, a w.a.g. You can't assume the parts people have given you the correct one just 'cause they say it is. Sometimes, parts get put in the wrong boxes, or, the 'puter at da parts store ain't hip to this sorta thing.


(don't ax me how I know these things... )

Adams' Apple38933.8385416667

I had the same problem on my 62 impala this spring turned out the new master cyl was bad replaced it and all was good

We have gone though three MC and finally installed a complete booster/MC unit.That hasen't done anything.I know what you mean about two different knids of MC.They sent the wrong one three times,finally got the right one and installed it and as soon as you applied any pressure at all the rubber seal in the MC would trun inside out and that in turn made all the insides spring ect to be off crooked.It all started out as a leaky MC that was under warrenty because this shop stands by it's work parts and labor for 90 days.By the way this is a stock 82 CF engine.For some reason I'm not getting any pedal presure.This shop has been in business for 40 yrs and they have never seen anything like this before.As a matter of fact the owner said a long time ago the got brbuilt kits for the MC but nodays with labor cost it's just cheaper to buy a MC than do a rebuild.

I thinkk I would get a master from somewhere else?
I have to assume that the master is being bench-bled before installing, and the rest of the system is being bled properly?
I have little faith in most reman masters these days, as well as reman alternators. Quality control is not a priority....

Man, I would get a new master too or make that shop replace the one they put in with a new one, just for the grief they are putting you through.  Good luck.

I was loosing my pedal last year, would bleed the system, put my foot down and it would go to the floor. I ended up changing the rear caliper brake lines, and the rubber brake hoses. It ended up being the rubber brake hoses were bad. Brakes work great sinse.