>From my experience and understanding of the braking system on these cars, this is completely normal. You are correct, they do not employ engine vacuum for brake boost, rather, there is a pump and a pressure vessel that is kept at sufficient pressure to give you the brake boost you need. Be thankful you hear that pump running, it is when you don't is when you need to start to worry. ----- Original Message ----- From: "Tim Clevenger" <tjclevenger@xxxxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Friday, June 04, 2004 10:38 AM Subject: IML: Hydraulic pump sound ('90 IMP) Hi all, When I'm driving my '90, about every third time I step on the brake, I get a sound like a hydraulic motor running for a few seconds. Is that some kind of brake booster, or is my ABS pump running when it shouldn't? I would expect that this car would have vacuum brakes like most others, so it wouldn't need a motor running. Thanks. Tim