ptbo

In my 86 5000S there is a small (1 mm) hole in the underside of the hydraulic servo where it meets the brake master cylinder. This hole is machined and appears (unlabeled) on a diagram of the hydraulic servo on the sjmautotechnik site. When I press my brake pedal in the brakes feel spongy like there is air in the lines and there is air and some brake fluid coming out of this small hole. Does anyone know what this is symptomatic of? Should this hole be plugged? Why is it there? Doesn't it's presence obviate the o-ring that seals the MC/servo union?

Thanks for any help here.

Kneale Brownson

Do you know it's brake fluid you're getting out of that hole? It could be brake fluid or it could be hydraulic oil from the power-assist system. If it's brake fluid, your master cylinder is leaking. If it's hydraulic oil, the booster is leaking.

That hole is supposed to be there. It's a weep hole for moisture that might collect from condensation/whatever in the space between the two fixtures.

ptbo

Thanks for the reply.

It is definitely brake fluid, I guess I need to replace the MC. The bad one on my car is a LONG-version one, I have a used SHORT-version one that came out of a 1990 100, Does anyone know if these parts are interchangeable? (sorry I don't have the numbers right now).

Thanks

Kneale Brownson

If I had a known good one sitting around, I'd definitely try it for fitment.