Alright, in my quest to find a master cylinder that fits my brake lines (I'd rather not make new lines) I decided to see if a LS1 master cylinder was possible. Well, I discovered that the one I found will not work.

The picture of the MC below shows that both threaded ports are the same size.

The two brake lines in the left of the 2nd picture are off my 86 Iroc. And the two on the right are from the LS1 master cylinder. Now the two from the LS1 MC have the same thread size as the smaller one from my '86. However, the larger one from my car does not match anything.

Now if you look in the raybestos catalog for an LS1 mc and a 3rd gen one they list the thread sizes as the same.

So I don't know what to do.

I'm probably just going to order a stock one for a thirdgen.

Maybe this info will help someone.

-Brent

 

I just installed one a month ago. Just bought the MC never had the ls1 lines. But mine was a direct swap. Little tube bending but every fitting was the same. Not sure what to think either.

 

what car is that cylinder from? 8cylinder, 6? abs no abs?
I know i used my original fittings and just played with the stock lines.

 

Yea, I was planning on buying a new one and just bending my old lines, but now I'm not sure.

Not sure what car its from.

I've been searching through rockauto.com and crossing parts and what not. The v6 and v8 98-02 models have the same part number listed. And the Raybestos one lists two different thread sizes. Unlike the one I have with the two ports being the same

Do you guys have similar stock lines coming off the MC like mine? I want to make sure my stock stuff isn't something weird.

 

your car is an 86, so is mine, they are identical. AFAIK all thirdgens had the same brake lines in this spot.

 

Man, I've had such bad luck with MC's, I don't know what to do.

The Bendix (supposed to be for a 3rd gen) one wasn't even close to the same thread size (see other thread)

Now the LS1 is giving me problems too.

I think I'm going to order just a regular 3rd gen one. I never would have thought that replacing the master was going to be so troublesome.

86TA - Thanks a ton for answering my questions. I appreciate it.

 

Maybe you could look up what it says in Summa Theologica about the topic. At the very least finding the right part would be evidence of there being a God.



Sorry... I had to. Durn Catholic School!

 

I feel your pain, Thomas.

JamesC

 

Installed one on my car yesterday, direct fit with a little manipulation of the brake lines...
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Are you 100% sure that MC is from a 98-02? It has the threads of a 93-97.

 

Well, the one I bought arrived yesterday and it works with my lines. Its the small bore one for a thirdgen.

Cadillac - hahaha! The real evidence would be that when everything is back together on my car that it works!

ES87 - I asked for one from a 98-02, however the guy could have sent me one from a 93-97. Is there another way to tell?

 

Whoever sold it to you probably figured they were all the same. As you can tell, they are not.