I have a spare 88 SE parts car. I have read numerous how-to guides on doing the 5-lug conversion. I haven't seen anyone mention swapping master cylinders or brake boosters.

My question is this? Are the brake boosters the same between an 88 SE and a 91 GXL?

A friend of mine has the 91 and his brake booster is leaking, causing his brakes to not work. I was thinking of yanking my brake booster of the parts car and selling to him cheap, but I want to make sure they will be compatible.

The reason I don't just go out and look is b/c my parts car is parked at my parent's house 2 hours away while I am at college.

 

They have different sizes and a bunch of P/N for each one, for example in the S4 models there is a one for the single piston front brakes, and one for the 4 piston brakes. Then on the S5 there is one for the Turbo and one for the N/A.

But you could use a S4 4/piston booster on a S5 N/A or a S5 N/A booster on a S4 4/piston brake system.

But I don't think you could use a S4 single piston booster on a S5 N/A. It appears to be just to small, although it may bolt up just fine.

 

But, how would a 5-lug conversion work then if I continued to use my 4-lug single-piston brake booster?

I haven't seen any 5-lug conversion kits include the master cylinder or brake booster before....just the wheel hubs, rotors, calipers.

Do you think it would work at all? Possibly have slightly less responsive/powerful brakes?

 

No one knows for sure?

 

I am sure it will be related to effort. You would certenly have more effort using the smaller booster with the heavy duty brakes to stop the same distance as if you had the correct booster that is matched to the brakes.