vn v8 pwr steering problem

[Eliminator]

Gday, my power steering seems to play up when the cars been driven for a while, on short trips the car steers fine but on longer drives, or especially a hot day with the a/c on, the steering goes stiff after a while and its harder to control the car but sitting in the driveway it turns fine. usually if i turn the a/c off or leave the car switched off for 5-10 minutes the steering comes back, would this seem like the pwr steering pump is overheating and causing it to fail at high temp?

If im driving along and the steering starts to go stiff the steering wheel still turns easy but if im going around a right corner the steering wheel will stay there until i move the wheel (doesnt centre itself)

[vn calais manual]

how low is your oil, and what kinda colour is it, sounds like the pumps heating up quite a bit.

[Eliminator]

I did a change of the oil from the steering rack so all of its been replaced and is topped up as i was thinking that the oil could of been the cause, im certain its the pump considering the problem only usually arises on a hot day with the a/c on, i did a test on the highway the other week, put the windows down and switched the a/c off and the steerign came good again, the pwr steer pump is relitevely close to the a/c compressor so i thought it was a heat issue with the pump and not the rack. But before i go out and buy a new pump i wanted some different opinions so i know im replacing the right part.

[Eliminator]

anyone????

[immortality]

certainly a weird one. have you tried fully synthetic power steering fluid? also, what is the belt condition/tension like?

personally i run a power steering cooler and the fluid temp never gets above warm.

[Eliminator]

no just plain automatic trans fluid which shouldnt be a problem, also the belt and its tension are fine.

[immortality]

actually, standard trans fluid is ok but there are certainly better products on the market. hgih quality synthetic fluid has prevented a lot of power steering problems in later model commodores.

just a slight observation, holden have used the same power steering pump for many years, however wheels have got bigger and wider, from anybody who has driven a car with a manual steering rack with big/wide wheels, it takes a fair amount of effort. this is also true for the power steering pump. your pump is getting old and no doubt your running wheels that are bigger/wider then factory spec. all this is putting extra load on the pump.

[Eliminator]

problem still exists..... i swapped over to another power steering pump and its still the same.. got both tierod ends off to check if its the suspension binding which its not.

All i can put it down to is either a power steering rack or the uni's that connect the column to the rack.

Has anyone ever experienced a steering wheel not returning to centre (and stiff) after heating the motor up????