Had the truck for three years now, only in the last week the steering is very hard to turn at idle when stopped. I have had 305 tires on it for the three years I've had it but it has always been easy to turn. There is no pump whine or other symptoms to note, once rolling or moving the steering effort returns to normal. Should I flush the fluid out or is there a relief valve something that can be serviced? My buddy has an 04 SS and his has done the same thing since he has owned it, I told him it steered like crap now karma has bit me.

Any ideas?

 

Most likely the EPC solenoid or the steering angle sensor on the steering shaft under the dash has failed. The pump has a small electronically controlled valve on the bottom that modulates idle boost pressure. This is controlled by the ABS module which gets signal from the angle sensor.

The simple test is to reach behind the pump and unplug the red electrical connector, then go for a test drive. With it unplugged you should have too much steering assist at all speeds.