I'm planning on converting my power front drum brakes to discs on my 1971 Olds Cutlass Supreme convertible. Do I require a new booster as in some kits or can I save some money and get a kit without one?

Brent

 

There are some attractively priced kits available that include everything needed for your conversion---including a booster. The cheaper kits are mostly parts made outside the good old U.S.A. and are fine for most builds. If you are going to be showing for points, these kits will not be for you. Also, most (not all) of the advertised "complete" kits use a larger caliper that won't clear 14" wheels.

 

The best deal found up here is $649 plus about $100 shipping. No free shipping via UPS up here . They bend us over freight wise anytime they can .
I have 15" American Racing wheels on the car, can't see any problem with clearance.

Brent

 

Hi, I converted my 72 Cutlass with 14 inch Ralley wheels last year. I do like the stopping distance and have done 3 bleeds, two on the bench. I have noticed the inside of rotor has a "wear mark" ... something is etching the inside. I think I will pull this off and look at the bolt pattern, could this be the problem? Toby in Ohio.

 

I have used the kit for a 4 wheel conversion from getdiscbrakes dot com, the fronts fit a 14 inch wheel , the rears rub because of the mounting brackets I used the new spindles but used my steering arms, I also got bit by the maw monster and added stainless lines, stainless flex, 9 inch booster, moved the proportioning valve under the master cylinder to allow better exhaust clearances and slotted and drilled rotor as well as powder coated calipers , it isn't cheap but the kit was great. I give it two wrenches up . The base kit is much cheaper and they do make a factory 14 inch kit, remember it is getting to be a biotech to find 14 and 15 inch performance rwl tires at least for me so u might want to go to 15's at least

 

I converted mine with a kit came with everything I think it was 789.00 off the top of my head
But that was Canada line & tube

 

To (finally) answer the O.P.'s question, no you do not need to replace the booster. The disc brake M/C bolts up and works just fine with your original booster.

 

But, isn't the proportioning valve different, drum to discs?

 

Check out www.scarebird.com A proportioning valve is only for adjusting the pressure to the rear brakes to insure which ( front or back ) locks up first.

 

Well, considering that drum brake cars DON'T USE a prop valve, yeah, they're "different". Again, not the question the OP asked...

A-body disc brake conversions are trivially easy. I suggest reading this thread:

https://classicoldsmobile.com/forums...sk-brakes.html