Difference between 68 power and non power Brake MC
Thread Starter
Racer
Joined: Jun 2001
Posts: 334
Likes: 6
From: Newark De
Difference between 68 power and non power Brake MC
I am upgrading to a Dual reservoir Brake Master Cylinder on my 64 Coupe (non power brake) and was looking at the 68 Brake Master Cylinder. I will still be running the Drum brakes until I can get the disc brake parts swapped over. But what are the differences between the Power Brake and non Power MC's. I assume either one should be able to move the fuild needed for the drums but which would be best..
Thanks
Don :chevy
Thanks
Don :chevy
Melting Slicks
Joined: Feb 2001
Posts: 3,330
Likes: 13
From: Europe , Luxembourg
Re: Difference between 68 power and non power Brake MC (jump150)
Hi
As far as I know, the non power barke MC has a thinner piston in order to get more food pressure to the brakes.
The power brake MC doesn't need this as it is assisted.
I wouldn't install either one wiseversa .
If your car has PB, use the PB MC , if non PB , of course the non PB MC.
Good luck. Gunther
As far as I know, the non power barke MC has a thinner piston in order to get more food pressure to the brakes.
The power brake MC doesn't need this as it is assisted.
I wouldn't install either one wiseversa .
If your car has PB, use the PB MC , if non PB , of course the non PB MC.
Good luck. Gunther
Melting Slicks
Joined: May 2001
Posts: 2,131
Likes: 4
From: May help you? You can sure as hell try!
Re: Difference between 68 power and non power Brake MC (jump150)
The power brake MC has a bore diameter of 1 1/8". The manual cylinder has a bore of 1". Because of the smaller bore diameter, the manual cylinder gives more mechanical advantage at the expense of greater pedal travel. The PB cylinder doesn't require the extra mechanical advantage because of the vacuum booster. I believe the original PB cylinders have a casting number ending in 346 and the manual had a number ending in 509 (going from memory here).
Team Owner
Joined: Aug 2000
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From: Massillon,Ohio USA
2020 C3 of the Year Finalist - Unmodified
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Re: Difference between 68 power and non power Brake MC (LemansBlue68)
I believe the original PB cylinders have a casting number ending in 346 and the manual had a number ending in 509 (going from memory here).
Safety Car
Joined: Oct 1999
Posts: 4,101
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From: NorCal
Re: Difference between 68 power and non power Brake MC (Paul Borowski)
Paul, is this '68 only or the same for '69? I have a sneaking suspicion I have the wrong cylinder on my late '69 PB car, because the travel is way off. They work great, just too much travel.
Hans
Hans
Melting Slicks
Joined: May 2001
Posts: 2,131
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From: May help you? You can sure as hell try!
Re: Difference between 68 power and non power Brake MC (Wrencher)
The same casting numbers were used for quite a few years. Well in to the '70's. Somewhere in the early 70's they deleted the bleeder screws but the flat boss areas for the bleeders remained.
Drifting
Joined: May 2003
Posts: 1,634
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From: Melbourne, Victoria, Australia, the World
Re: Difference between 68 power and non power Brake MC (jump150)
There is also a difference between Drum and Disk brake Masters. Unsure about Vettes but other drum brake masters have a little check valve in the outlet to stop fluid flowing back too fast. Helps you pump them brakes!
:cheers:
:cheers:
