Hey, I have a friend who has a '92 International bus, and when you turn the key on, a pump runs constantly. I had a few minutes with him, and checked a couple of things, but my bus has air brakes, so I'm not exactly sure what's up.
Anyhow, here's what I've got:
- The pump seems to be controlled by the lower switch that is opened by the brake pedal being depressed, so I think it's a hydraulic 'assist' pump.
- The pump will come on when the brake pedal is depressed, even if the key is off.
- Once the key is turned on, the pump runs constantly, whether the engine is running or not.
Any ideas? I was wondering if the switch was shorted, but it seem to work fine triggering the pump when the key is off - should it? The brakes work fine, but he's worried about the wear on the pump, which I can understand. Thanks!