The Project Pad

Seems like they would, but wondering if anyone has used a b4 brake booster on a b3 car?

I remember the B4's booster being bigger, but don't remember by how much.

DE80q wrote:I remember the B4's booster being bigger, but don't remember by how much.

hmm, that might be problematic. Bigger in diameter or depth or both?

I'm pretty sure it was just diameter.

I have a couple at home. I'll try to check tonight to see what I have and the differences. I know I used a B3 booster on my V8 Coupe but I had previously tried another

b3 9", b4 10" diamter. it fits

varia wrote:b3 9", b4 10" diamter. it fits

any deeper?

It fits Dana.

Isn't the B4 brake booster the one people use to do the vac-assist swap in a B3, along with the modified PS pump?

That's what is in the picture..........

PRY4SNO wrote:Isn't the B4 brake booster the one people use to do the vac-assist swap in a B3, along with the modified PS pump?

both B3 and B4 booster can be used. I used B4 90/cab ps pump (with 7A bracket on the 3B engine) and B4 90/cab ps pump rack-to-reservoir hose.

PRY4SNO wrote:Isn't the B4 brake booster the one people use to do the vac-assist swap in a B3, along with the modified PS pump?

I've always used a booster from a b3 when I have done the conversion, but they seem impossible to find now. Looks like I will try a b4, might make my assist a little better too.

How's the feel and power compare to hydro assist?

It always seems a little easier to me, but im not sure I have ever had a power assist that worked perfectly. Hydro assist definatly feels more hydraulic and vac assist feels more airy? How is that for a description

Haha kinda... one feels more solid, the other feels a bit... flimsy?

My 80q has the old g54 calipers and hydro assist. The brakes actually feel way more responsive/powerful than my Coupe (hydro assist) and B4 90q (vac assist), so I assume that means the hydro-assist on my Cq is on it's way out?

(sorry to threadjack )