Power brake drum/drum master cylinder

[1970Chevrolet]

I searched and searched and can't find an answer so hopefully someone can help me out. I need to find a power brake drum/drum master cylinder. I have a 1970 C10 and it has a power booster but it also has a manual master cylinder. so there is a lot of play in my pedal before it engages the brakes. It is my understanding that on a manual master cylinder, the hole in the cylinder for the push rod is like 1.5" deep and the hole on the power master cylinder is a very shallow indention. So my push rod is basically 1.5" away from touching the cylinder, which is causing so much play in my brake pedal. Does anyone know where I can find a power master cylinder? I have looked on all of the parts stores websites and can only find the manual ones. I'm not sure if there is another year that would interchange. Any help is appreciated, thanks.

[AnotherWs6]

Shouldn't be hard to find. Are you looking to purchase one or just want a photo? I bought a power booster and master combo fro Classic Industries a few months ago before I decided to ditch the 4 wheel drums.

[1970Chevrolet]

I'm looking to purchase one. I have seen the booster/master combo, but I think my booster is fine, so I really only need the master cylinder and can't seem to find one by itself. Can't find a part # for the master either on those combos.

[1970Chevrolet]

Do you happen to still have that master cylinder? If you do, would you mind seeing if there's a part number on it somewhere? Thanks!

[AnotherWs6]

I don't, I returned it.

I found this on rockauto.com - It lists several 67-70 car applications that are power drum, but does not specify the type of brakes when listing the trucks that it fits.

http://www.cardone.com/Products/Prod...p=rock&jsn=437

[1970Chevrolet]

From the picture on that site, it looks like a manual master since the hole looks like it's deep and is not just a small indention. It looks like the same one I have on my truck that I got from Oreilly's.

[firedemon]

couldn't you just make a longer pushrod out of a grade 8 bolt to take up the extra play or it wont physically bolt together?

[toolboxchev]

Just picked up a new lifetime master cylinder at NAPA, with a lifetime warranty for about 60 bucks.

Have tried the Cardone stuff, not happy. Lifetime parts go about 7 years and then there is issues.

[1970Chevrolet]

Originally Posted by toolboxchev

Just picked up a new lifetime master cylinder at NAPA, with a lifetime warranty for about 60 bucks.

Have tried the Cardone stuff, not happy. Lifetime parts go about 7 years and then there is issues.

Would you mind getting the part number for the one you just bought? Is it for power brakes or manual?

[toolboxchev]

Originally Posted by 1970Chevrolet

Would you mind getting the part number for the one you just bought? Is it for power brakes or manual?

Hang on a minute, I will get it for you.

Napa Premium Line, NMC M36246. Try napaonline.com, you order and ship direct to your home.

[1970Chevrolet]

Originally Posted by firedemon

couldn't you just make a longer pushrod out of a grade 8 bolt to take up the extra play or it wont physically bolt together?

It's the intermediate pushrod. It doesn't bolt to anything, just slips in between the master cylinder and booster. I guess I could make a longer rod, but I would rather just have the correct master.

[RichardJ]

CPP sells the same Master for Power or Manual. They supply a pin that drops in effectively turning it into a shallow hole to mate up with the adjustable Booster pin. There is no need to make a big deal about it.

[1970Chevrolet]

Originally Posted by RichardJ

CPP sells the same Master for Power or Manual. They supply a pin that drops in effectively turning it into a shallow hole to mate up with the adjustable Booster pin. There is no need to make a big deal about it.

Thank you for this, that is good information. Not sure why you felt the need to add that last sentence though. Thanks anyways.