Master Cylinder Interchangeability

[Heg87t]

Hey,

Shopping for a new master cylinder for my car. I have decided to get a 1" bore since my 1.125" gave me too much travel before application of the brakes.

Question is are all power brake master cylinders that bolt up the same?
If it has the correct 3.5 bolt pattern and line sizes will it work? I would like to get a newer small style reservoir master if it would work.

What's your thoughts/ Anyone else running different masters? What are you guys with Bear, S10, or LS-1 brakes using for a master?

 

[RmvBfrFlght]

Going with a smaller bore M/C will increase the pedal travel. As it displaces less fluid in the same length of stroke.

In your sig you have "dual 2.125" piston calipers." That is a lot of piston area (6.6 sq-inches). I'll bet they clamp like a shark on a tuna fish.

A smaller bore M/C will provide a higher line pressure and a longer stoke.

A larger bore M/C will provide a lower line pressure and a shorter stroke.

M/Cs vary as there are ones that are quick take up, along with ones that have residual pressure check valves for drums systems.

If you like the pedal pressure with the 1-1/8" bore M/C, and it is a standard design. Can try a quick take up in the same bore size.

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[Heg87t]

Hey,

Thanks for the info. I was using an iron 1 1/8" MC from a 78 B-body and it worked well. Stopped pretty fast once you got the pedal down. It started leaking as well as my rear hose so I need some repairs which may be the reason for my dissatisfaction. I have a 1 1/8" aluminum MC for an '84 B-body in inventory that I think I will put on. Do you know if this aluminum MC's quick take-up? Think it's a good candidate?

Store Locator | NAPA Online

 

[RmvBfrFlght]

NAPA links never work right. Don't know why, just can't get anywhere with their site.

I checked for a '84 Impala on rock auto. Here is a picture of the M/C. Note how the mounting end of the M/C is larger. This is a quick take-up unit, the larger bore at the back end is the large piston for the quick take-up.

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[Heg87t]

That looks like the MC I have. I will put it on and let you know how it works in a couple of weeks when I get her going again.

Thanks for the help

 

[RmvBfrFlght]

That looks like the MC I have. I will put it on and let you know how it works in a couple of weeks when I get her going again.

Thanks for the help

Check hood clearance between the reservoir and bracing. I was reading a lot of threads here last night on brake stuff. In one it was mentioned that the reservoir of the mid-80's b-body M/Cs is taller. The person ended up swapping the stock reservoir in place of the b-body one.

Other then that possibility it should bolt right up. Same dimple depth and outlet port sizes as a stock N/A Regal vacuum M/C.

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