[IRA51]

the hydraboost pump is used to give you power steering and boost the brakes so they have power assist like a seprate vacume booster but done with hydrolic's .check the fluid level first ,if it is empty you may have blown a hose or a seal (better than blowing a walrus I have been told) if it is a bad hose you have a 50/50 chance that it will be fine with a new hose and a refill with fluid . it is an easy job to replace the hydraboost pump and sometimes all it is is a bad valve in the pump . you should be able to get a rebuilt one for under $150.00 but you will have to shop it . a new one is pricey. there are some shops that specialize in rebuilding racks and hydraboost pumps and are more reasonable than a new one .There is always NAPA and they will warentee it includeing labor if you have a shop install it for you. we have had a problems with 2005 Avalanche's that we have fixed with just a new valve and they are good as new .no need to remove the hood just leave it alone and get it from the top and bottom ,should not take more than 2 or 3 hours . and if any of you make fun of my spelling,I will hunt you down and make you drive a Prius with a Al Gore bumper sticker .