Power Steering Hydro Boost Problems

[Tinman]

I have an 03 Duramax Crew cab that has 35 inch tires and wheels. I had no problems for 70,000 mile, then my pump went out and after replacing it with a stock unit. It was good for about a week then became very difficult to turn when parking. I then bought a high performance high volumn pump from AGR, I thought my problem was fixed. How wrong I was after a day the same symtoms returned. I did a preasure test after the hydro and had 1500 psi without appling the brakes and it dropped to about 1100 psi with the brakes applied. If I raise the RPM's it is better, but not what it used to be. I think that there may be a restriction in the hydro boost. What do you think? A volumn problem? Anyone deal with this problem before? My dealer says there are no service bullitins or recalls covering this problem. I do not mind spending the money, if the problem is corrected.

Thanks, Tinman

[More Power]

I assume you replaced the fuild when the pump was replaced. What's the condition of the PS fluid after the problem appears?


Jim

[Tinman]

Yes, I replaced all the fluid when changing the pumps. Checked further on Friday and found that after by passing the Hydro Boost unit still had steering problems. Noticed that the fluid was hotter than should be expected and decided to call AGR for some recommendations. On Saturday I bought and installed the largest Transmission cooler I could find and changed out all the fluid I could evacuate with Valvoline Sythetic. The problem is not completely solved, but there is a definate improvement. Our thought at this time is that the high volumn, high preasure pump was creating excess heat due to pushing the fluid through at a much faster rate. I will follow up later this week with additional info as it becomes available. BTY that increased heat problably lowered the viscocity of the fluid as well.

[Tinman]

Good News, The transmission cooler and synthetic fluid seem to have done the trick.