After a 5 mile drive in my 1987 Allante (144,000 miles), I arrived home to find my brakes fail just as I entered my garage. Had the car towed. Mechanic said the fusible link, from the battery power terminal at the front of the engine compartment to the brake relay, on the passenger fender near the front of the antifreeze reservoir, was 'burnt up." When this happens there is no power to the brake pump(booster). The fusible link wire was replaced.

Drove it on 3 or 4 short trips, 3-4 miles each. Lost power to brake pump again. towed to Shop.The fusible wire again was replaced.

Back at home, in the garage WITH THE KEY OFF I could hear the pump trying to start. By this I mean it would begin to whirr for 2 or 3 seconds . This suggested to me that the relay might be bad because, I'm told, that if the relay fails, then the pump would run continuously until the pump burnt itself out. (however Dick Hussey/Allantesource told me it was normal for the pump to come on to keep the pressure up)
Fearing that it might run the battery down I disconnected the battery. The next day, I drove back to te garage. This time he looked at the relay and said I needed a new one. I got a used relay with the pigtail, including the fuse link (wire). Worked great for 4 or 5 days (although I didn't drive it very much), then failed again. I had it towed again. The mechanic doesn't know why. He did install a NEW relay and fusible link and test drove it. I drove the car home but, now I am afraid to drive it because it could burn up again leaving me with no brakes.

Any advice will be appreciated.


1. Lost power to brake pump. Replaced fusible wire from remote battery terminal under the hood to the relay.
2. Lost power to brake pump. Replaced fusible wire again .
3 Heard pump whirring for a second every minute or so to maintain the proper pressure in the brake pump, even though key was off. (If I turn the key on, initially it runs approximately 25 seconds to build up the 2600 lbs. of pressure it needs to operate; then after a minute or two I can hear it trying to come on to maintain the pressure. I am told this is normal.) So, I returned to the garage. Mechanic said the fusible link, the pigtail and the relay should be replaced.. I got the parts used from a reliable source.
4. Drove less than 20 miles. Parked car for an hour. When I left I lost power to brakes within a mile.
5. Replaced the fusible link wire and replaced with new relay. Test drove. Drove home , but am now afraid that I might lose power to the brake pump while in traffic =. So far I have been lucky when it has happened.

 

there are not many experts on this field, but Dick is one of them .. highly advice that you get on the phone with Dick .. he wont charge for the call and he may solve the problem ...


please, please, please ... post the solution .. this is how we all learn ...
thanks

 

Cadillac Care in Marietta, Ga says the ac***ulator needs to be replaced. The ABS pump is supposed to build up 2600 psi in the ac***ulator which is released when one presses the pedal. It should have enough pressure to apply the brakes a few times before the pump has to run again to build the pressure back up. Because it won't hold a charge the pump runs every time the brakes are applied. This causes the pump to run so much that it overheats? the fusible link wire, burning it out, resulting in no power to the pump

I ordered the ac***ulator from Allantesource and will get the car back next week.

 

So far, so good. But, I don't want to jinx myself by saying it's fixed. Have only put about 100 miles of localdriving