2001 Astro Van, Hydroboost

My 2001 Astro van has developed an intermitent problem with loosing the boost while braking. About 12 months ago I lost both the brake boost and power steering, replaced the pump and life was great again. Then two months ago the boost for the brakes went out, I had to really stand on the brakes to stop (I was going slow <5 mph and turning) then the brakes worked fine. After this happened a few more times, I thought that the pump was going bad so I replaced it again. thats been about a month, and it has happened a few more times, always while going slow and turning, like pulling into a parking space. When it happens, the pedal feel like the ABS kicks on for a second the the boost is gone. If I release the brake and reaply the work fine. I have good pads, the calipers are clean and work smooth. I checked the ABS sensor wiring by the wheels, and it looks fine. HELP before I take out all the parked cars near me.


It sounds like you do your own work.

I’m not sure this is specifically ABS problem or just a red herring.

However I told myself that the first time I have ABS trouble I am going to buy a scanner, like the one in the sears catalog -Actron ABS Brakescan $79.99. Sears gives coupons, sales, etc. You can probably beat that price.

I don’t know how well they work or if I’m on the right track, but for the cost of 1 hour diagnostic labor, you own the tool!

Thanks, I have thought about a scanner, but I thought they only picked up trouble if a warning licht cane on. I have had no lights.



You could be correct. That is why I say your problems may be a symptom and not a cause. I’m not sure, but I’m thinking the “ABS” light might have to illuminate. I do know that my regular Actron Pocket scanner will not diagnose ABS brake problems, only PCM type issues.

Found the answer to my brake problem. Rust builds up under the ABS sensor, this increases the air gap and reduces the voltage produced by the sensor at slow speeds. the computer thinks the wheel has stopped and prevents the brakes from appling fully. Go to www.eautorepair.net, 29.99 buys one year of very detailed info with service techs.