Fluid Leak/Sensor

Ok. I have checked this system and I need more help. There is a switch/sensor located on the leftside (facing the engine, opposite side of the Master Cylinder) that is making a loud clicking sound. This switch/sensor is located beneath the BAP and behind the EGR sensors against the firewall. Whenever this sensor begins to make that clicking sound the brake fluid starts to leak from beneath the Acumulator/Master Cylinder. However, when I disconnect this sensor/switch the fluid stops leaking, but then the power brakes are gone and the brake/ABS light comes on in the car.

What is this switch/sensor called? You think if I change this switch/sensor the leak would stop?

What year SC?

If it is an '89 to '93 model SC, then you have the Teves Mark II ABS and I suspect you are talking about the ABS Pump Relay (aka Brown Pump Relay). When the pressure sensor/switch on the hydraulic unit senses low pressure, it sends a signal to the relay to cycle on the pump. It sounds like the relay is powering up the pump but the increase in pressure is causing fluid to spew through a leak. As the fluid leaks, the pressure drops, the sensor triggers the relay, which turns on the pump, which causes fluid to leak, and around we go again. If you disconnect the relay, the pump won't cycle on, but you have no system pressure resulting in no brakes (or at least no brake assist which is basically the same thing).

Locate the source of the leak and repair it if possible.

Thank you. It is a 1990 SC Anniversary Ed.

What is ironic is this leak and this continuous clicking sould only happens in the morning. In the afternoon/evening I have no problems. There isn't drop of fluid in the evening. Why would it only leak in the morning when I leave for work, but not in the afternoon/evening when I am on my way home. It only happens in the AM hours while driving to work. I can drive home with no problem/leak at all. The clicking sound only occurs when I depress the brakes in the evening, but it is a continuous click sound, whether I am depressing the brake or not, in the morning.

So do you think it is the pump that is the problem or the relay that is the problem? You think the relay is over pressuring the pump causing the fluid leak? I think I will go with the least expensive and change the relays. If that does not work then I will have the pump changed.

I don't want to sound dumb, but the is pump and acumulator the same? I know the acumulator is the black ball like tank behind/beneath the M/C and it seems to sit on what maybe the pump. I just didn't know if the two must be replaced as a unit or can it be replaced separately.