[wakesupremo]

Now that my motor is all working as expected (11.41 @ 122 mph), I feel that the brakes could do with a bit of care. I have a master power brake disc conversion on the front and a willwood 4 pot calliper system on the rear. The master cylinder, as far as I'm aware, Is a GM m/c with equal sized reservoirs. Both quite big and servo assisted, Should the front brakes come from the front pot or the rear pot and, obviously opposite for the rears?
Thank you in anticipation.

[Tom Vaught]

I would investigate putting a Power Corvette 4 wheel Disc Brake master Cylinder on the car. Equal reservoirs, equal apply pistons, and should bolt right on to your Brake Diaphragm on the firewall.

Tom V.

I run 4 wheel disc brakes on a 64 GTO with 9" rear.

[wakesupremo]

Thank you for that info Tom. That is possibly what I already have on there but not 100% certain. The pots are both the same size approx 1 3/4 "- 2" cubed. The front reservoir has the hole to the piston at the front and the rear reservoir has it further back.
The issue that i seem to have is, because the master cylinder leans slightly back the front resevoir hole becomes un covered on hard acceleration letting air into the system. Therefore I have to bleed relatively frequently.

[chuckies76ta]

Originally Posted by wakesupremo

Thank you for that info Tom. That is possibly what I already have on there but not 100% certain. The pots are both the same size approx 1 3/4 "- 2" cubed. The front reservoir has the hole to the piston at the front and the rear reservoir has it further back.
The issue that i seem to have is, because the master cylinder leans slightly back the front resevoir hole becomes un covered on hard acceleration letting air into the system. Therefore I have to bleed relatively frequently.

That makes no sense. The master cylinder with never let air in the system. You must have the wrong M/C. Post up a pic of it.

Front port is normally front brakes with rear port for the rear brakes.

What is servo assist?

[Tom Vaught]

The early cars I believe had some that were plumbed the opposite of what you mentioned, Chuckies 76ta.

A Chevelle master would be plumbed possibly different vs a Corvette master. Sounds like he has posswibly a Mount issue vs a reservoir issue as both are the same size.

Tom V.

[pfilean]

I'm running C3 Corvette discs all four wheels. All four piston calipers. GM dual master cylinder equal reservoirs. Front to front rear to rear. Really no problem. But then Imine sits relatively level. Not the tilt I have seen on some GM applications.

[Schurkey]

Originally Posted by wakesupremo

The front reservoir has the hole to the piston at the front and the rear reservoir has it further back.
The issue that i seem to have is, because the master cylinder leans slightly back the front resevoir hole becomes un covered on hard acceleration letting air into the system. Therefore I have to bleed relatively frequently.

Originally Posted by chuckies76ta

That makes no sense. The master cylinder with never let air in the system. You must have the wrong M/C. Post up a pic of it.

Post SEVERAL photos, including the interior.

There's no way the transfer ports from reservoir to cylinder should ever get uncovered.

In a disc/drum system, the larger reservoir always goes to the front (disc) brakes. The larger reservoir may be in front, or in the rear--but the larger reservoir always supplies the front discs. In a disc/disc or drum/drum system, it shouldn't matter

[Elarson]

I'm converting my '75 Firebird from power brakes to Wilwood manual and had to reverse engineer what the factory intended.

The power brake booster mounts to 4 studs on firewall and the MC tilts down in back to point at the lower hole on the pedal (4.5:1 pedal ratio).

Mounting the manual MC directly to the 2 upper studs on the firewall makes it level and pointed exactly at the top hole on pedal (6:1 pedal ratio).

Eric

[wakesupremo]

Thanks for all the replys. I'm not clever enough to know how to put pics on here but, I've owned the car for 17 years, when I first bought it it was drums all round so, the first mod was a master power brake system for the front end. I feel relatively certain that there was already a booster / servo on there. I'm also fairly certain that the kit had a new M/c so that would have been swapped over but still mounted the same. Then as I got faster the rears needed attention so have a wilwood 4 pot caliper system there. I don't recall swapping the M/C for this upgrade, the M/C has 2 identical sized reservoirs both about 2 1/2 inch cubed. It has the normal type GM lid set up. The brake pedal has always been a bit slow on returning once pushed, Not sure if thats relevant or not.