Hey everyone, I replaced all of my accessories on the front of my engine (even though they didn't need it, but everything had 130k miles on it) while doing some other major work to the front of the engine recently. I replaced the power steering pump (original one gave me no issues) and the first replacement from AC Delco left me with no power assistance below 1,000 or so RPM. I got another replacement pump from AC Delco and thought all was good when I had easy steering at idle, but quickly found that after a certain MPH of full throttle the power steering assistance completely goes away and takes several minutes of normal driving to return. The wheel becomes completely stiff. I have found that once this happens, if I blip the throttle enough (ie: enough for the transmission to step down a gear) the power steering comes right back and stays until the next time I get really heavy on the throttle. Has anyone else had or heard of this same problem? I can't seem to find anyone else on the Internet reporting the same issue on any other car.

I did bleed both power steering pumps immediately after firing up the engine for the first time since the pump was installed, by turning the steering wheel lock-to-lock 30 to 40-some times. Thanks!

-Andrew

 

Sounds like you learned the hard way, "If it ain't broke then don't fix it." What I'm finding odd is that your original one worked correctly, but the first replacement pump worked the opposite of the second replacement pump. Cutting out at idle versus high RPMs. That tells me the issue is with the pumps and not your vehicle.

 

Thanks Alloro. Yeah, but I literally replaced everything else and wouldn't have made sense to me have everything else new and leave a couple things alone, then have to go through removing the fan/clutch and radiator shroud again later.

Yep, sounds like the problems are opposite between both pumps. And this pump had a bent pulley that AC Delco installed before shipping it. I only drove the car for maybe 10 miles before I realized the problem was the pulley, but at this point I think this is that last time I'm buying AC Delco parts for this truck. Everything I've bought is AC Delco "Professional" series, and ball joints I installed in April have been making noise for months now, and I've been sent 2 bad pumps from them (assuming this one is bad too).

I'm just trying to now determine for sure if it is the pump or not before I go tearing things back apart again. If it's an RPM issue (not an issue deriving from the VAPS/EVO, which the system is variable to MPH when working properly) then I could/would just test that theory by revving the engine to 4-5k in park and see if the steering tightens up. If so, to me, that would indicate a pump issue. Only problem is that I cannot rev past 3k or so RPM while in neutral or park to test that :|

Any ideas?? Thanks again!

 

Are the pumps for Navi and Expy different? Make sure you've got the correct pump for Navi, not sure if there's a difference but the Expy doesn't have the VAPS feature.

 

Hey Skauber! Yeah, according to Fordparts.com and Rock Auto they are the same pump. I think the VAPS feature is all solely in the steering rack and the VAPS controle module, which is integrated within the air suspension module on these trucks.