Hi, my '95 Camry with 160K miles has erratic power steering. It’s particularly bad when driving off from a cold start in the morning. The problem is not related to any particular turning movement, although it never occurs with small steering corrections while going straight ahead. I’ve checked the obvious things: belt tension, and fluid level. The fluid is fairly dark, but not foamy. I’m thinking it’s a malfunction in the power steering pump, and I’m thinking of putting in an additive. Lucas and Rislone both make an additive, although the Lucas seems more targeted towards leaks and the Rislone is called a “steering stabilizer”. Any opinions on whether these are likely to help, and which one do you think would be better? Thanks, Bob
What you’re describing is called “Morning Sickness”.
This is where the steering is very difficult when the vehicle is first driven for the day, and it’s a result of worn spool valve seals in the steering rack & pinion.
Tester
The pump does one thing: pump. If it’s failing it’ll typically either make a racket or fail. You could remove the belt and see if the front end of the pump feels loose in-and-out (axial play) or sideways (lateral play) or does not turn easily (binding). The pump is a possibility here because of the dark fluid.
The rack contains both the piston that assists you in turning and the proportional valve (spool valve) that directs the pressuriized fluid to one side of the piston or the other when you turn. Either of those can act erratically.
Before trying an additive I’d purge and refill the fluid with fresh. But chances are you’ll have to replace a component. If you’re losing the power steering in cold weather I’m betting on the rack. They use elastomeric seals for the piston and those could be contracting the cold and allowing the pressurized fluid to pass by the piston rather than assisting you.
Thanks for your help. I siphoned out the P/S fluid from the reservoir and refilled it a couple of times (after driving around, of course) and the problem seems to be gone! It occurred to me after it was fixed that a key piece of info that I left out of my original post was that the car hadn’t been driven for 2 weeks immediately before the problem showed up. So I’m thinking that the valves were acting erratically, but the new fluid and some exercise has freed them up. Thanks!
Cool. Thanks for posting back. We so rarely hear.