2004 Volvo dp SM power steering issues

[Perfect Storm]

Steering is stiff at all speeds when minimal pressure is applied to wheel. With a hard jerk to wheel, power assist kicks in.

Have done or tested the following:
Replaced steering cable
Verified cable and actuator move freely
Replaced fluid
Pump is quiet and works perfect once the actuator engages the ram (both directions)

Other observations:
When engine is off actuator slides freely back and forth from stop to stop (about ? inch)
When engine is started actuator returns to center position and will only move about 1/8 inch
If manual pressure is applied to actuator in either direction the power assist will engage or
If you jerk the wheel the power assist will kick in.

These conditions exist at idle speed, neutral or while on plane. It appears that the actuator requires more force than necessary to engage. I have been to a Volvo dealer and they are not sure if it is the pump or actuator and could not give quote. Can you tell me with the information provided if I have a bad actuator or pump? Thank you for your help

Drive
DP-SM 1.95 (M22)
3868913
4202083553

Transom
TSK SX-MHP
3868850
4151033226

 

[Perfect Storm]

I have since contacted Volvo Penta for information on their actuator and this was their response:

Volvo Penta commercialize the actuator as a complete assemble and we do not service or provide technical specs for dealers to service this component.
We are also not the original manufacturer of it so there is not technical specs or tolerances available from our engineering department.

This is something a dealer has to diagnose after inspecting it.
We suggest trying another dealer, to see if they can help.

Best regards,
Volvo Penta of the Americas
Customer Relations
Telephone: 866-273-2539
Telefax: 757-436-5150
Visit our website: www

As you can see, no help whatsoever from Volvo, they would not provide me with the mfg. of their actuator.

In addition to the above, I replaced the helm and flushed the system with Seafoam's hydra trans-tune. This has helped somewhat. I also talked to a couple of dealer mechanics and they said the only thing left would be to replace the actuator. They felt that my steering was as good as it is going to get, and that the $1000+ replacement may or may not make a difference. I was reminded that it is power assist and not what you expect in the fine engineering of an automobile. Pretty sad that the marine industry is still using 65 year old steering technology.

 

[Perfect Storm]

Follow-up on this posting. Bit the bullet and purchased a new power steering actuator. Same results, stiff steering at all speeds. Also purchased a pressure tester for the pump and found the following results:

Engine idle with deadhead valve opened -150 psi. (Normal I think)

Engine at 1500 rpm valve open. 300 psi

Engine idle valve closed. 1400 psi

Engine idle with actuator manually forced all the way to retracted position and held. Maximum pressure 150 psi. Doesn't this low pressure point to a bad actuator?

 

[Perfect Storm]

Where can I find the Volvo Penta workshop manual (or procedures and specs) to pressure test the power steering pump and to test the steering actuator cylinder? I have a clymer, but it tells me nothing as far as specs, psi, etc.

This is for a 2004 DPS drive with an 8.1 liter.

Thanks for your help