noisy power steering

[mistaake]

My truck makes an awful squealing noise when I am turning all the way left or right. It's not loud when straight or normal turns.

I will check the fluid level in the pump tomorrow. If it's low, what should I add? Just any "power steering fluid"? I remember in my 89 Ford econoline I had to use ATF type F instead of power steering fluid.

If the level is good, should I replace all of the fluid anyway? It's over 15 year old fluid.

 

[firebane]

Check your belt tension and make sure its tight.

 

[mistaake]

Belt tension is good in fact we just put on the brand new belt. High quality gates brand.

 

[chengny]

My truck makes an awful squealing noise when I am turning all the way left or right. It's not loud when straight or normal turns.

That noise is normal when the steering is brought over to the end point - and the steering wheel is held there. It is the sound of the internal relief valve (flow control valve) opening and allowing fluid to recirculate within the pump. This is necessary since - with the steering gear at the stops - there is no place external to the pump for the P/S fluid to go.

The easiest solution is to not hold the steering wheel over hard - just back off a bit.

If I am not understanding the condition as you describe it and the pump makes that squeal not only at the end points but also on the way to the end points - it's time for a new pump (unless you feel like rebuilding yours).

 

[mistaake]

Only makes noise when all the way left or right. So it's normal? Awesome!
Should I still eventually replace the fluid Since its been sitting so long?
Thanks

 

[firebane]

Only makes noise when all the way left or right. So it's normal? Awesome!
Should I still eventually replace the fluid Since its been sitting so long?
Thanks

It will only make that noise if you are putting pressure on the extreme left or right of the pump. And yes it doesn't hurt to flush the fluid once in a while. Just take off the return line.

 

[mistaake]

Cool, thanks - I was all worried that my pump needed to be replaced, but I think just not holding the steering wheel all the way over while turning is the easier solution. Last time I did it I was making a u-turn by the bus stop... certainly turned some heads with the noise

Do you happen to know if power steering fluid is like brake fluid in that it attracts water?
Thanks.

 

[chengny]

Hygroscopic is the term for a liquid with the ability/tendency to absorb water (in either liquid or vapor form) from the surrounding environment.

Brake fluid is highly hygroscopic (for reasons given below)

Other hydraulic fluids used in automotive applications (incl PS fluid) are not hygroscopic


The two primary reasons that brake fluid is formulated to be hygroscopic are:

1. To prevent pockets of water from forming within the brake lines. This is important due to the high temperatures developed under hard braking conditions. If a standing leg of water is allowed to form in the brake line (esp near the drums/rotors) and the brakes are applied long and or hard enough, the heat of friction can cause any nearby water to flash into steam. While brake fluid and water are incompressible (and can transmit pressure/force hydraulically), steam isn't like that. It is very compressible and virtually useless at transmitting hydraulic pressure/force. So when this condition occurs, the brake pedal goes soft - or in extreme cases goes right to the floor - and all braking power is lost in that hydraulic circuit.

2. Also to prevent pockets of water forming but this reason is about mechanical failure of brake system due to corrosion. If water pockets are allowed to form in the brake lines they tend to find a spot and stay there. Over time the water begins to corrode the brake line from the inside out and eventually it will eat a hole in the steel wall of the tubing. Then one day, when you slam on the brakes, the line pops and hydraulic pressure is gone in that circuit.

 

[MadOgre]

I still have not found any reasoning that says I cant just use ATF in my power steering.

2 years ago I replaced the power steering gear box, the power steering pump and all the lines as it is a Hydro boost system.

I filled with regular ATF and still have no issues with it. This summer I may drain and refill with a synthetic multi type ATF but I have found no reason to spend big $s on actual power steering fluid.

Anyone know differently ?

 

[flyboy1100]

My theory is power steering fluid is for power steering. The capacity of the system is what, less than 2qt? How much money are you really saving by using atf? Couple of bucks?

 

[MadOgre]

about $50-60

Mine has a bigger reservoir and also twice as many lines as well as the capacity of the brake booster unit

 

[flyboy1100]

Oh, I know nothing about that system. Usually PS fluid costs about the same as atf here, so I guess I would still use PS fluid unless the owners manual said otherwise.

 

[CSFJ]

I've used atf in place of ps fluid in many vehicles over the years. Never had a problem. If the system is a little low and still has ps fluid I'll use that, but for big leaks, atf is much cheaper.

 

[MadOgre]

Oh, I know nothing about that system. Usually PS fluid costs about the same as atf here, so I guess I would still use PS fluid unless the owners manual said otherwise.

Its $35 a liter/quart here for power steering fluid vs $20-25 for 5 liters/quarts of ATF

It would cost me over $100 to fill my system with power steering fluid vs $16 for ATF

 

[flyboy1100]

Its $35 a liter/quart here for power steering fluid vs $20-25 for 5 liters/quarts of ATF

It would cost me over $100 to fill my system with power steering fluid vs $16 for ATF

That is crazy! Wonder why it is priced like that in Canada.