Power Master Cylinder

[rcazwillis]

Anyone know if any parts stores have power master cylinders. The one from NAPA was a manual. Their parts list did not distinguish power vs manual. Tried one, manual. Oriellys does not distinguish.

I know online vendors have it, like to buy these type of items local.

[jocko]

They should have both. I like to buy this kind of stuff local also - much easier to return, which seems to be necessary all too often. I believe the only difference between power and manual mc for a given configuration is the depth of the pushrod hole in the piston. If I recall, the power mc has the shallow hole and the manual mc has the deeper one, but it’s been awhile... How did you determine the one you got was a manual rather than power? I’m pretty sure last one i did this I got it at OReilly - for a 71 C20.

[LockDoc]

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This Raybestos master cylinder (RMC39075) is listed as being for a 3/4 ton with power brakes. Here are the cross reference numbers for other suppliers. I don't know how current this list is or if part numbers are still good.

[rcazwillis]

Originally Posted by LockDoc

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This Raybestos master cylinder (RMC39075) is listed as being for a 3/4 ton with power brakes. Here are the cross reference numbers for other suppliers. I don't know how current this list is or if part numbers are still good.

So the 3/4 ton should be the same? I was wondering if there was a difference.

[rcazwillis]

Originally Posted by jocko

How did you determine the one you got was a manual rather than power? I’m pretty sure last one i did this I got it at OReilly - for a 71 C20.

The deep hole in the plunger. Oreilly said they would order them to see what works. May go with that option.

[jocko]

3/4 ton and 1/2 ton mc's are not the same. On a 3/4 ton mc in 71 (I assume this is for your 71?), the forward port is for the rear brakes and the rear port is for the front brakes - opposite of the 1/2 ton mc. Yes, the 1/2 ton mc is more intuitive, but that's what ol uncle GM did. You need to specify 1/2 vs. 3/4 ton as well as power or manual when buying to make sure you get the correct one.

[rcazwillis]

Yes on the 71. I ordered the part from Classic Parts last night along with front hoses. Hope they are long enough.

Thanks for the quick response on the 3/4 vs 1/2. I assumed they were different.

[LockDoc]

Originally Posted by rcazwillis

Yes on the 71. I ordered the part from Classic Parts last night along with front hoses. Hope they are long enough.

Thanks for the quick response on the 3/4 vs 1/2. I assumed they were different.

That's why it is always a good idea to state in your first post what you are working with.....

LockDoc

[demian5]

This is a great way to look up parts along with rock auto.

http://www.centricparts.com/