Most place like Autozone and Advance Auto PArts list a few different ones, I believe a 6" and an 8". Which one do I choose? I think they had an 8" one with the reservoir for like 10 bucks more. Should I just go with that one to make it easier? Boy is my MC shot all to hell.

I have had to replace mine and I think that it is 8" I'm not sure. All you need to do is measure your orignal one and go from there

I would say to get a reman with a lifetime warrenty from NAPA and reuse your old reservoir.

I think that I paid like 30 after the core

Woah. How sure are you it'* 8"? I've had a 5.5" on my car from day one. This would explain why it feels like I don't have enough pedal....

My 94 had a 6" master. I picked up an 8" from a junkyard thinking that it would fit. It doesn't. The resivoir is too tall and won't fit under the strut tower brace. Just measure the one you have, and get the same size to replace it with.

If you have another car, remove the MC, and take it with when you get the new one to compare the two. That way you'll know its the right size. I do that all the time, because the idiots that work at Autozone/Napa [sorry Kenn, had to say it], Advanced Auto, and Pep-boys screw up my parts all the time.. and I NEVER walk out there with the wrong part [I think they have my pic in the back and it says at the bottome "don't eff with this guy"]. Don't take your MC out and expect to drive your car there though .


-justin

If you want a good one get an AC-Delco, they won't give you a choice of sizes, they will give you the right one.

Things I've found in the past 20min;

My books list one MC for 92-95
which ACDelco crosses to 174-860. No one else can use this number. Advance and RicerZone don't carry ACDelco.

Bumper to bumper says that number is no good, But they only list XDE174-860 as the MC for my car. And they'd have to order it.

Figuring you have the right MC on your car you could just measure the one on there. However, I'm not confident I have the right one now.

So, What are the differences in cars that require the different sizes?

Autozone asks if you have disc/drum, and ABS. I see no reason ABS matters, but anyway.. all 92-95'2 have disc/drum.

I had the long one (assuming 8") and replaced it with the short one (assuming 6") and i have exactly the same pedal feel.

http://www.teamscr.com/grmbrakes.html

Guessing isn't good enough when selecting a master cylinder. If they both truely served the same purpose GM would have no reason for creating the extra expense of two parts. I don't know why AutoZone and others list two master cylinders as available for use when most here have reported to be using the 8". There'* some difference, obviously stoke, but bore may differ too. Who even wants to calculate what that would do to ABS effectivness.

Can anybody think of some telltale that may be present on a car to indicate which MC would be used?