Steering hydraulic pressure adjustment?

I would think that the amount of pressure in the steering system would not affect the "feel" but the amount of "play" in the system when traveling over uneven ground, with lower pressures resulting in more "play".

Sounds more like an > Hi. My new 2004 Chevy TrailBlazer steers sharp, but there is no feel in my

If the brake fluid was air, not hydraulic oil then I suppose your first explanation might be valid.

Yes, it's a design flaw if the steering system's oil pressure is nonadjustable. And yes, tire inflation and tire profile (height) both do relate to steering force, but it can't be blamed on the tires. Any tire would certainly require *more* steering force if it was underinflated, and that problem is exacerbated by tall profile tires, so you could deduce that the reverse is also true. However, P245/70R16 tires are not taller than what's standard on most SUVs. The steering system is designed for the specified tire size, their normal inflation, and the vehicle weight, among many other factors.

There will be a pressure relief valve in the pump - on this vehicle, it seems to be specced to open at 1500 psi and is not adjustable.

A pressure relief valves is a redundant safety device set at a pressure slightly above the normal operating pressure range. I doubt if that valve cycles open/closed to maintain 1500 psi at the steering actuator.

There must be some other (internal) pressure regulating valve that's built into the pump.

It's actually called a "power steering pump flow control valve" - it's a spring-loaded bypass valve that's screwed into the pump housing. That's the only pressure-regulating device I can find any mention of, and it's not adjustable (really, why would it be?)

Thanks, Bob. OK then, that's the pressure regulator valve. I can understand why the engineers wouldn't have selected an adjustable one, as it's not

*imperative* to have adjustability, and a fixed pressure one would be lower cost than an adjustable pressure one.

I'm glad at least that it's an external component to the pump (not integrated in the pump). I believe that I can replace it with an adjustable one available from either an industrial supplier or fluid power components distributor.

In fact, I've already found one (Prince RD1850H) available at Grainger for $33

It has a 1000-2500 psi adjustment range. That one should be able toproduce a satisfactorily lower actuator pressure than 1500 psi chosen byGM's engineers. Of course I'll need replacement fittings and tubing toaccomodate the replacement valve. The existing valve, tubing and fitting canbe removed undamaged for future reinstallation if necessary.