Steering help!!!!

[scottmcd]

I have a hiss that sounds like it is coming from under the dash, whenever I turn the steering wheel. When I checked the power steering fliud level, it was under pressure. Levels were good, little dark, but did not need to add any fluid. When you put the cap back on, and rotate ther steering whell, it builds pressure back up in the pump. The fluid is NOT foaming. My mechanic is a little dumbfounded by it all at this time. Thinks it may have something to do with the HYDRO BOOST. Any ideas???? TIA, Scott

 

[scottmcd]

Flushed the system and replace all the fluids, and I am still getting the hissing sounds. Was hoping that new fluid would help the situation> Any thoughts on this issue?

 

[RonD]

I had this on my 55 Chevy street rod, drain some fluid, then add some TransX to it, a good guess it will be gone in a week, great stuff, after the problem is gone drain and refill with ATF4, the transX expands the pump seals.