Kim,

I don't have a Syncro, but this sounds just exactly like the problem I
had in my 88 GL. Turnedout to be an internal leak in the master
cylinder. Changed the cylinder out and it was fine after that.

John Rodgers
88 GL Driver

Kim Brennan wrote:
> So, last weekend I went through the task of putting in a new brake
> master cylinder on the GoldBrick, my 86 passenger Syncro. It had
> classic symptoms of a failing master cylinder, so that was an obvious
> fix. Flushed the brake fluid, bleed the brakes, and all is happy. Got
> it through Virginia State Safety inspection and its good for another
> year (strange thing is it probably wouldn't make it through a Maryland
> inspection due to some of its rust...but that's a tale for another
> time.)
>
> On my Westy Syncro, however, the brake problem is different. The
> symptoms are as if I had air in the brake lines, but I've bled the
> brakes (and flushed the fluid) all the way around. Essentially if I
> step on the brake pedal and pump it multiple times I'll get braking
> action. However, occasionally, when I hit the brake pedal quickly (and
> release) I'll hear a pneumatic flapping sound (like air going through
> a diaphragm.) When that happens I get excellent brake feel, where
> you'd expect it, about 1 inch after depressing the pedal.
>
> Most of the time, however, its down near the bottom of the floor.
>
> I've been pondering this and considering that it might be the booster,
> but it can't just be that. So I'm going to try and replace the master
> cylinder on this vehicle too. Unless folk have other suggestions as to
> what it might be (discs all around, SA big brakes up front, Smallcard
> (Audi) discs in back...all done within the last 6 years, and I've
> replaced the pads up front, once since the big brakes were installed.)
>
>