2004 Chev Astro - 4.3L AT Hydroboost problem FIXED

[Pauls Automotive]

Here are the details for this vehicle; 2004 Chevrolet Astro RWD. 4.3L engine with automatic transmission. it is 4 wheel disc drakes with Hydroboost.

Here is the issue. It came in about a month and a half ago with a power steering complaint and and compalint the brakes were hard to stop. We found then power steering pump was leaking. We repalced it with a rebiuld A-1 unit. It seemed to be fine. Power steering returned and brakes were fine. We delivered the vehicle and a week later the customer has the same complaints. On reispection we found the power steering pump was not producing pressure. itr was still full and no leaks. We then oreder a brand new pump from Delco (this is our normal procedure but didn't realize it was available in new at the first repair) We installled the new pump and everything was great. delivered the vehicle and it stayed out about 3 weeks and returned with the same issues. This time the pump was producing pressure. After doing alot of checking we decided the hydroboost seemed to be the only answer. We order a brand new one not wanting to use rebiult and this has already become a big embrassemnet. We returned the vehicle and it has returned again in 2 weeks.......same issues. This time we replaced both pressure hoses and both cooler hose. One pressure hose had to be custom made as it was obsolete. After installing & testing it the problems remained. The only other thing in the system is the steering box. We did notice the problems did come on more after makes a hard turn toward the steering locks while on a lift so I decided to through a new box into it to see what happens. It didnt fix anything. So here we sit. The entire system has been replaced and we still have this problem. What the heck are we missing. This has become a total embarassement as well as a financial drain. any thoughts would be greatly apprecaited.

Paul

[steven kiser]

i had a situation similar to this. it came into my shop from a used car dealer and someone had replaced the pump. the system was never flushed and the pressure valve was hanging up. i believe you have to carry them from pump to pump. the system needs to be flushed thoroughly. i can almost guarantee there is debris floating around in the system. see if the relief valve is scored. if it is it may be sticking, check the spring tension as well. i've seen the relief valves installed backwards. just a tip here. i believe that these pumps had big issues with the shaft snapping filling the system with debris akin to an a/c system with an exploded compressor. there may be an extended warranty on this.

[Pauls Automotive]

We found that the pressure valve was sticking intermittently. It would only do it occationally and only under hydraulic pressure. Whenever we tested manually it was fine. We finally decided to get it acting up and shut the engine doiwn right away. we pulled the line off the back of the pump and the nut and sure enough it was suck. Got a new one and the spring and it hasnt done it since.

[steven kiser]

thanks for posting the fix. makes me all warm and fuzzy when i can help.......