["70" Cougar]

Hey folks,
My friend is building a bmw. i believe its a 80's model 2door. ( looks like a fish bowl) he wants to use non power chevy breaks in this car to reduce future costs. his question is will say half ton truck master have enough pressure to stop this car. I said it should as its a tiny car. also he's unsure of master placement as there's little to no room in the engine bay. Thanks for any help.
bill

[joe_padavano]

Here's a silly question - why not just use the M/C that comes from the same type of car as the brakes? Then there's no question that it works. Failing that, you should match the piston diameter in the M/C with the one that was used with those brakes originally.

[powerrodsmike]

I will second Joe P's answer. The most important aspect of master cylinder choice is the bore size relationship to the calipers, following that , there are springs and valves intergrated into some master cylinders that govern pressure output, front /rear bias and timing and residual pressure.


If he can't make sure that his new master cylinder will have the same characteristics in operation as the OEM part, then he should not try to cheap out by buying a MC intended for another type of brake system. (you did say his first concern was cost)

I've never worked on a bmw, so I have no idea what they integrate into the MC...but I would do some research to find out before I just went ahead swapping parts.


I'll add this, a 1/2 ton chevy truck MC is probably way too big for the small piston calipers that are probably on that bmw.



Later, mikey

["70" Cougar]

Ok sounds good. I'll let him know to stick with the o/e.
thanks for the info.
bill