04 Tahoe/Power steering too light

[Joe Valle]

04’ Tahoe 4wd , power steering is too lite at Hiways speeds . Need reduced pressure when driving Hiways. Low speed PS operation is normal . what can be done to a 04’ ? Joe

 

[Donal]

Power steering too lite sounds like maybe the air pressure in the tires is higher than the recommended pressure, tires are not the recommended size and load rating, wheel alignment is not within the recommended specifications, the suspension height adjustment is out of range and so on.

"Steering too easy" and "steering too hard" are identified in the repair manual. The repair procedure is the same for both conditions. The repair procedure appears to be to vacuum degass the power steering fluid once the source of entrained gasses and or other contaminates have been removed from the system. Common sources of entrained gasses, (air,) are repairs, low fluid levels, seals allowing air to enter the system, etc.
An operator may try turning the steering wheel lock to lock and hold there for 5 to 6 seconds several times. This action may allow entrained air to escape.

 

[GatorBite]

I would recommend bleeding the power steering system. Check and top off the power steering fluid, jack up the front end, start the truck and turn the steering wheel lock to lock several times but don't hold it at lock, shut down the engine, and check the power steering reservoir. add fluid if needed. if heavy bubbles, there is air in the system. repeat until bubbles are significantly reduced and fluid level doesn't drop.

 

[Joe Valle]

My question should have maybe been more exact . My good friend has an 02’ Tahoe that I have lots of seat time in . Her steering at hiway speeds has what feels like a reduced pressure which give a great hiway feel . Being a retired professional foreign all our Tahoe’s are in great condition . Tires are correct sized Yoko . Trying to learn , did 02’ have reduced pressure at speed & 04’ Tahoes did not ? Learned a little on utube but not clear enough for me to replace the pump !

 

[MassHoe04]

I have an 04 Tahoe Z71. While it does not feel at all like a Porsche or Ferrari, it does not feel "light" in steering at any speed.

Z71 is running 265/70 R17 at pressure recommended on the door sticker.

I would not say it is tight, but does give what feels like decent feedback and tracks straight.

 

[Matthew Jeschke]

You can use a mighty vac. I ordered a metal one. Use it quite frequently, however, you'll need to rig up a fixture to hook it to the revivor cap. The doorman section in your parts store has a fitting then you can get a rubber plate or something to seal it up. I did this when I rebuilt my power steering system. Worked like a CHAMP.

Also, is the vehicle new to you? There's two power steering options on the 4wd light duty chassis/gmt800. There's the Delphi 670 gearbox and the larger 680 gearbox. I rebuild several of them then learned this...

My steering was SUPER easy, turns out I have the 680 gearbox. I didn't realize there were two options for steering system on 4wd Tahoe. Since I started driving off road the power of the larger gearbox is AWESOME. However, on road it is a tad light / responsive.

Have you rebuilt or replaced your power steering pump? I believe mine has a setup that disables the pump at a certain RPM, possibly to avoid it being too responsive. Look at back of the pump there's a electrical connector that hooks up to the pressure regulator on the pump. Anybody else can chip in on this, if I'm off track but I believe the pump free spins after a certain RPM, or dramatically reduces it's pressure. If there's an issue with that harness / system I'd imagine you'd have really light steering at high speed... especially if you have the 680 gearbox.

 

[Donal]

My question should have maybe been more exact . My good friend has an 02’ Tahoe that I have lots of seat time in . Her steering at hiway speeds has what feels like a reduced pressure which give a great hiway feel . Being a retired professional foreign all our Tahoe’s are in great condition . Tires are correct sized Yoko . Trying to learn , did 02’ have reduced pressure at speed & 04’ Tahoes did not ? Learned a little on utube but not clear enough for me to replace the pump !

Looks like two optons for power steering pump for 2004 Tahoe.. One for the rpo codes Y91 and bph and one for with out those two codes.

 

[MTahoe]

While there are a couple of different gearboxes, they are all Valved for variable power assist.

All of the things discussed CAN cause
Light steering. However, there are many variables in tires and alignment alone that can cause different feel from vehicle to vehicle.

If it feels “very” light at highway speed, it’s likely that the varisteer is not working properly.

You can still get the steering angle sensor, but not the solenoid on the pump. You can read about how to undo the solenoid, but there is some work involved. That is also not a very good pump design, and they are difficult to find as “good” units without varisteer or the related components to make the gearbox work with it.

On mine, I put a new pump from a 2018 2500 on the engine, and if I get the motivation, I’ll change the gearbox to a pre-varisteer unit. The new pump was much less cost than replacing with the older design, and is new. This fixed most of what I was experiencing, and alignment to
My specs help more after that.

I had a solenoid that would not work as it should have.

The 2018 pump doesn’t have the solenoid built in, as the later models move it to the steering rack.