Troubleshooting Power Steering

Stamey

Petty Officer 1st Class
Joined
Aug 7, 2010
Messages
286
This is a 1996 Mercruiser 4.3LX. The PS does not work. The pump is full and when I turn the wheel I hear no strain from the engine trying to run the PS pump, ever, even at the locks. I tried wiggling the wheel back and forth and when I do that I can feel faint assistance, but not for long, maybe 2 degrees to turning.
I do not have a pressure gauge to test output of the PS pump and am trying to figure out how to troubleshoot without that.
The manual says, "NOTE: DO NOT attempt to repair or adjust the later model control valve." From the diagrams in the manual, I think that's what I have. I am thinking the control valve is stuck.
Engine SN: 0F821477
Stern drive SN: 0F678198

Any ideas?

Thanks,
Chris
 

Stamey

Petty Officer 1st Class
Joined
Aug 7, 2010
Messages
286
Re: Troubleshooting Power Steering

Thanks, but same manual I already have. I do have the new style valve and can see it moving back and forth as the wheel is turned, but I get no assistance from the PS, nor does it ever put a load on the engine. Is my only way forward and pressure gauge plumbed in now?
Does anyone have the fitting sizes/types I will need?

Thanks,
Chris
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Troubleshooting Power Steering

Thanks, but same manual I already have. I do have the new style valve and can see it moving back and forth as the wheel is turned, but I get no assistance from the PS, nor does it ever put a load on the engine. Is my only way forward and pressure gauge plumbed in now?
Does anyone have the fitting sizes/types I will need?

Thanks,
Chris

Ayuh,.... I believe the hi-pressure line is 3/8" inverted flare, like automotive brake lines...
 

Stamey

Petty Officer 1st Class
Joined
Aug 7, 2010
Messages
286
Re: Troubleshooting Power Steering

OK, so i broke the PS lines while removing them from the actuator, as they were rusted solid. I then posted here for advice on replacing them. I got my new lines with the quick disconnects (thanks AChris) and installed them. I cannot find the necessary fittings to plumb in my pressure gauge to troubleshoot the PS system per the manual. It is some kind of flare with an o-ring on the end and a size of 14mm x 1.5. That beast is nowhere to be found, so I'm back to troubleshooting, in a more primitive manner.

Filled the pump with ATF and bled it by running the high pressure line into the low pressure line (the quick connects are quite handy for this) then split them and held my thumb over the pressure line, inside a bucket, and at engine idle it pumped all of the fluid out in about 3 seconds.
Reconnected the lines to the actuator and bled the system per the manual, then had a friend cycle the wheel back and forth, engine idling, and me pushing/pulling against the outdrive, to provide some pressure for the PS to work against. Here and there I could feel the PS kicking the outdrive, rapidly, so as to make the outdrive shudder in whatever direction it was going, right or left. I looked at the actuator with my helper turning the wheel back and forth, and could see the sleeve the steering cable goes through sliding back and forth in the actuator body, about 1/4" one way or the other, and it seemed to come to rest in the middle of its travel when my helper stopped turning the wheel.
As I understand it, I have the later, one-piece actuator that is supposedly non-serviceable.
Is there anything else I can do to troubleshoot this, or should I call it an actuator problem, and I suppose, buy and actuator?
If I absolutely have to put a pressure gauge to it I will have to take it to a dealer, who has the special tool to test the pressures since I am unable to find the necessary fittings.

Thanks,
Chris
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Troubleshooting Power Steering

OK, so i broke the PS lines while removing them from the actuator, as they were rusted solid. I then posted here for advice on replacing them. I got my new lines with the quick disconnects (thanks AChris) and installed them. I cannot find the necessary fittings to plumb in my pressure gauge to troubleshoot the PS system per the manual. It is some kind of flare with an o-ring on the end and a size of 14mm x 1.5. That beast is nowhere to be found, so I'm back to troubleshooting, in a more primitive manner.

Filled the pump with ATF and bled it by running the high pressure line into the low pressure line (the quick connects are quite handy for this) then split them and held my thumb over the pressure line, inside a bucket, and at engine idle it pumped all of the fluid out in about 3 seconds.
Reconnected the lines to the actuator and bled the system per the manual, then had a friend cycle the wheel back and forth, engine idling, and me pushing/pulling against the outdrive, to provide some pressure for the PS to work against. Here and there I could feel the PS kicking the outdrive, rapidly, so as to make the outdrive shudder in whatever direction it was going, right or left. I looked at the actuator with my helper turning the wheel back and forth, and could see the sleeve the steering cable goes through sliding back and forth in the actuator body, about 1/4" one way or the other, and it seemed to come to rest in the middle of its travel when my helper stopped turning the wheel.
As I understand it, I have the later, one-piece actuator that is supposedly non-serviceable.
Is there anything else I can do to troubleshoot this, or should I call it an actuator problem, and I suppose, buy and actuator?
If I absolutely have to put a pressure gauge to it I will have to take it to a dealer, who has the special tool to test the pressures since I am unable to find the necessary fittings.

Thanks,
Chris

Ayuh,.... Have you pulled the end of the cable, Outa the aluminum tube yet,..??

They're known to corrode, Badly inside the aluminum tube....
 

Stamey

Petty Officer 1st Class
Joined
Aug 7, 2010
Messages
286
Re: Troubleshooting Power Steering

No, I have not pulled the steering cable. The steering cable had not been suspect because the steering is pretty free even without the PS working, but I have to use a hand to turn it rather than the single finger I would expect if the PS was working properly.
I tried connecting another hose to the return line, then running that line to the pump, through the fill cap. Had my helper hold it and ran the engine. When I turned either direction I could see the hose jerk a little, which suggests that the valve works for a second, here and there, but does not maintain position to provide the power for any length of time.

If I pull the cable what will I be looking for, and what will tell me good or bad, and if I should grease and reinstall or replace?

Thanks,
Chris
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Troubleshooting Power Steering

No, I have not pulled the steering cable. The steering cable had not been suspect because the steering is pretty free even without the PS working, but I have to use a hand to turn it rather than the single finger I would expect if the PS was working properly.
I tried connecting another hose to the return line, then running that line to the pump, through the fill cap. Had my helper hold it and ran the engine. When I turned either direction I could see the hose jerk a little, which suggests that the valve works for a second, here and there, but does not maintain position to provide the power for any length of time.

If I pull the cable what will I be looking for, and what will tell me good or bad, and if I should grease and reinstall or replace?

Thanks,
Chris

Ayuh,... as I said,..... Corrosion.... Clean it out, grease it, 'n put it back together...

The actuator valve works only when it senses pressure...
The jerkiness ya see is normal, 'n happens so fast when workin' ya can't see it/ don't notice it...
 

Stamey

Petty Officer 1st Class
Joined
Aug 7, 2010
Messages
286
Re: Troubleshooting Power Steering

Pulled the cable out of the actuator. There was zero corrosion, but the grease that was on it was kind of dry and sticky, so I cleaned it off with carb cleaner, and took a bottle brush doused in carb cleaner to the sleeve the cable goes in, then greased the inner part of the cable and outer, and slipped it back in. No help.
On the up side though:
1. When I had the cable out I started it up and used a pry bar to push the valve sleeve both ways. The out drive moved both ways by way of the PS cylinder.
2. When the cable was out I turned the wheel to move the cable while cleaning/greasing it and it was still a bit stiff to turn. It didn't take one finger but wasn't terrible with one hand.

I am now wondering if the problem is my cable. Now, let me temper all that I have been saying by stating that I am comparing this to my last Mercruiser, a 1983 Chaparral, which, when running, you could turn with one finger. Am I expecting too much from the PS system on this boat?

Thanks,
Chris
 
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