Hey, I have a brake problem I am having trouble diagnosing. I was taking a small trailer to a friends house and when I came to a stop at the house, the Brake and ABS light came on. I let off of the pedal and they went off. I was in the process of backing the trailer and every time I pressed the brake pedal, the lights came on and progressively got slower to go off until they stayed on.

I checked the fluid and it puked brake fluid out of the reservoir. I have never seen or heard of that before. The fluid was fine before. It also was pretty hot, which I have no explanation for. I checked the codes on the ABS but did not get it to respond. I then checked for vacuum on the brake booster which was there. I do not know what else to do. It has been fine up until now, but I need it to go to work tomorrow in.
PLEASE OFFER IDEAS!
Chris

 

I don't know what to make of the puking brake fluid. Having the brake and ABS idiot lights on at the same time is often the vacuum switch, either no vacuum to the switch or a problem with the switch circuit. I'm not sure where the switch is on your truck, on mine it's teed onto the main vacuum line up to the booster.

 

Your right about the vacuum switch, I checked the vacuum and it is pulling pretty hard, darn near sucked my finger up in it. I disconnected the vacum switch and it had no effect. I checked a few other things and I think I found it.

I was looking at the solenoids in the service manual. Checked the hydraulic proportioning valve, then figured I would check the fuse just for some unknown reason. Blown! I have never seen a blown fuse cause so much havoc. I guess the trailer has a bad wire or something on it. It is a new trailer, but I replaced the fuse (20A) with a 15 A to check to see if it would blow again without the trailer. It didn't after a road check. I will replace it with a 20 after a few days if it doesn't blow. The 15 will show any thing that may be putting a heavy load on it that shouldn't be.
When I replaced the fuse and turned the key on, about three solenoids clicked really loudly. Any ideas as to what these were?
Chris

 

I don't have an explanation of the brake fluid though. It was really hot, maybe when the solenoids shut down, it created high pressure in the system and it had to go somewhere? I don't know.
Chris

 

How long has it been since you flushed your brake fluid?
It may be full of water that boiled from the extra heat caused by the non functioning trailer brakes and puked the system.

 

Brake fluid is the most overlooked maintnance on a vehicle, most think that it is never to be changed out, when it is in reality one of the top two fluids that need changing on a regular basis. Goodluck,,,Rick