difference between power and manual master cylinder

[blacksleeper]

What is the difference between a power master cylinder and a manual master cylinder?

The reason I'm asking is I want to replace the single master cylinder on my Skylark with a lightweight plastic/alum. dual master cylinder off of a early 90's S-10 pick-up. Napa has a rebuilt one w/power for $60 less than the manual one. I've done this before on another car but used one for a manual application. Does anyone know if the power one will work for a manual application? Thanks in advance. Mike

[GStage1]

I believe it will work.....in the older cars....I believe the bore was slightly larger on a manual master..... 1 1/8 vs 1" for power

[bw1339]

I believe it will work.....in the older cars....I believe the bore was slightly larger on a manual master..... 1 1/8 vs 1" for power

Wouldn't it be the other way? Larger bore equals more force required from the pedal.

[blacksleeper]

That's what I thought also, but wasn't sure. Anybody else have any info on this? Thanks, Mike

[paul c]

i do know that the cup in the piston is deeper in the manual one so the pushrod won't fall out. i did this conversion on my camaro and that was the main difference. as far as the bore size goes the larger one will push more volumn compared to the other pushing more pressure which i think you need the smaller one for pressure since there isn't any assist. i may have that backwards.

[gsjohnny1]

manuals run a smaller bore. being you have drum brakes, you will need a block and a 1" bore master. the rod length i cant help w/o looking at it.

[blacksleeper]

I am planning on switching to disc brakes. So, since the caliper piston is quite a bit larger than the wheel cylinder, maybe I'd be better off using the power master cylinder since it has a larger bore. Mike

[GranSportSedan]

The correct thing to do would be get a master cylinder for a manual disc brake car such as a olds W-30 or a vette. they would have the right volume as well as the correct size bore for pressure

[bignastyGS]

The correct thing to do would be get a master cylinder for a manual disc brake car such as a olds W-30 or a vette. they would have the right volume as well as the correct size bore for pressure

That's what I did on my car(manual disc setup) and the master cylinder is huge compared to the stock drum units. But it has a greater fluid capacity for when I really need it. Gonna be an exciting car for me as it has manual steering and disc brakes..

[paul c]

like i stated. if you use a power master it only has a dimple in the piston, the manual rod will fall out. you have to spend the extra for the manual one. the reason that they are more is there were fewer vehicles with manual, especially later on like s10's. i used a vette unit. yes it is heavy cast but it will work. spend the $ on a Strange unit.