i have a 66 olds f85 power brakes...drum all around....my single resovoir master is on its way out....i want to put a dual res in its place....keeping the power streering.....can i put one off a same size newer gm?...that has power drum brakes too?....

 

This has come up before so if you have time try the search function to see what you can find. I'm pretty sure you'd be save with a 1967 master cylinder, they have two reservoirs. But I don't know how much newer would still be the same. John

 

no that would be great.....thank you....i didnt realize that they changed it in 67....do i need anything else?? or just bolt it on the booster and split the brake lines..thank you ..

 

You need to use the 1967 drum brake master cylinder. You also need either a 1967 power booster or you need to modify the pushrod between the booster and the M/C on your current power booster. The dual M/C requires a much shorter pushrod. And of course, you'll need to split the brake lines. The best way to do this is to get a drum brake distribution block from any 1967-72 car. You'll be bending and flaring brake lines to fit. Note that GM used non-standard flare nuts on the brake lines in some places to ensure that the lines could only be assembled one way. You can get these flare nuts from the tubing specialty houses, but don't expect to find them at a normal auto parts store.

 

understood...thanks alot...front res feeds the back and back feeds the front?......forgot which is which....

 

check with Master Power Brakes or Inline Tube or some of the other brake houses as they may make a brake line kit to convert it. I know on the earlier cars they do. I have done a couple of 60-64 chevys that we converted to disc with a dual master and bought the line kit that includes new front lines and a line to connect to the current rear line.

 

I beleive you are correct

 

I'm pretty sure it's front-feeds-front and back-feeds-back, but on the drum brake M/C it really doesn't matter since both sides have the same bore and reservior size.

 

Yes, front feeds front, etc. You need to change the distribution block and use something to go from the front output of the master to both front lines. The rear line can go directly to the cylinder. Pep Boys and probably others have stub lines with the big nuts for the master cylinder. You can use couplers, etc. from parts houses. You may be able to get a special plug for the original distribution block to cap off the port for the rear line. Spray clean after making up the new line setup and make darn sure there aren't any leaks. Use only steel brake line with double lap flares.

 

great
will do ....off to pep boys..