Loss of power steering @rpm below 1800

[RichKimball]

As the title implies the wheel is a bear to turn at low rpm.
Here is what I have checked/serviced:

All kingpins and steering linkage inspected/greased.
Bellcrank replaced with SuperSteer brand. (original was not bound up)
Flushed and replaced transmission fluid for power steering system.
(Did not have any trouble getting old fluid out or new fluid in...so I rule out blockage)
According to FL DTNA there is no inline filter. Straight from reservoir to pump to steering box.
FL tells me spec flow is 4gal/min. I have not checked this but I do see fluid bubbling up in the tank during a high idle (1200rpm).

Other than taking it to FL for service I don't know what else to do. Like I mentioned...if the rpm is higher than 1800rpm the steering works great.

Thanks for any input. I suppose I could try to self install a pump. It's located behind and driven by the air pump unit.

[twinboat]

Do you have a hydrolic fan running off the same pump ?

If the hoses on the priority valve are mixed up it will supply more pressure to the fan motor.

Second thought, there should be a pressure relief valve in the pump. A peice of debris may have lodged in it, letting some pressure bleed off.

[RichKimball]

Originally Posted by twinboat

Do you have a hydrolic fan running off the same pump ?

If the hoses on the priority valve are mixed up it will supply more pressure to the fan motor.

Second thought, there should be a pressure relief valve in the pump. A peice of debris may have lodged in it, letting some pressure bleed off.

Hi...there is no other hydraulic devices attached to the PS system.
Looking at the parts breakdown of the pump...there is a pressure relief valve.
It may be worthy of my time to drain the fluid once again and inspect the valve.

[RichKimball]

I decided that since it seems the output flow is low at low rpm but once the engine rpm is higher the steering works okay...and it could be a sticking pressure relief valve or....

Since the fluid needs drained to check the valve..and the fact I found a new TRW pump on eBay for $135 shipped...I will go ahead and replace the pump.

It doesn't look like it's a terrible job to replace from what I can see...accessible from either the top or bottom of the engine bay.

[garykk]

You don’t mention if you changed the filter in the tank.

[RichKimball]

Originally Posted by garykk

You don’t mention if you changed the filter in the tank.

What I did mention is that there is no filter on my system....and confirmed with FL.
Thanks.

[RichKimball]

Please to report that about an hour or so of labor replacing the pump unit and my steering is back to normal...maybe better than before.

Happy guy

[Skip426]

Thanks for wrapping up your post .
Glad you've got everything working right.
Safe travels.