Power Steering pump troubleshooting

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PS

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How can I tell if power steering pump is bad? I have a DHB on a 3.0L Merc. The steering feels like it has no assist
 
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camalot

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It,s more than likely the cable to be honest. A few quite and dirty checks, clamp the high pressure pipe coming off the pump if you here the pump hiss then the relief valve and pump are working. Remove the pin that holds the steering cable to the actuator and try the steering if still stiff change the cable. Whilst the pin is removed move the actuator tube from side to side ......the drive should move with the engine running.
 
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camalot said:
It,s more than likely the cable to be honest. A few quite and dirty checks, clamp the high pressure pipe coming off the pump if you here the pump hiss then the relief valve and pump are working. Remove the pin that holds the steering cable to the actuator and try the steering if still stiff change the cable. Whilst the pin is removed move the actuator tube from side to side ......the drive should move with the engine running.
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That's 1500 psi, how would that be clamped off safely?
 
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camalot

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It,s not 1500 psi is it............if it is .........it,s out of spec! Maybe I should have worded it "clamp it for a short period only" if the relief valve is working you will here a hiss at the pump. Or with the engine running turn the wheel all the way to the port and you should here a hiss. Or to be to be "safe" buy a hydraulic test gauge and measure the high pressure side of the pump and the low pressure side .
 
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I have an old 85 model boat with same engine but no power assist and when steering both feel the same so I think its not the cable. Can the pump be run with the cap off? Cannot find a place to loan pressure hoses
 
alldodge

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camalot said:
It,s not 1500 psi is it............if it is .........it,s out of spec! Maybe I should have worded it "clamp it for a short period only" if the relief valve is working you will here a hiss at the pump. Or with the engine running turn the wheel all the way to the port and you should here a hiss. Or to be to be "safe" buy a hydraulic test gauge and measure the high pressure side of the pump and the low pressure side .
Click to expand...

Yes it can be check your facts, the marine version of the same automotive PS pump uses a different relief valve. Auto is the same pump but relief valve pressure is around 700 to 900 psi.

#5

I have an old 85 model boat with same engine but no power assist and when steering both feel the same so I think its not the cable. Can the pump be run with the cap off? Cannot find a place to loan pressure hoses
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Yes, the pump can be run with the cap off. If you get oil splashing out then there is a clog somewhere or restriction. A standard PS pump can be had cheep but if you go that route, save the regulator off the old PS pump and use it on the new pump.
 
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PS

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Tried with motor running and turned steering to far left and then right. Pump had no noise during the movement or when deadheaded. Any idea what pump model number I should look for at the auto store?
 
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Also what power steering fluid should I use when replacing?
 
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camalot

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AllDodge said:
Yes it can be check your facts, the marine version of the same automotive PS pump uses a different relief valve. Auto is the same pump but relief valve pressure is around 700 to 900 psi.
Click to expand...

As per the manual with the test gauge connected to the high pressure side ........close the valve for no longer than 5 seconds, the reading should be 1150-1250 psi(7932-8621 kPa). Not very many people would have a test gauge that's why I said to do the "quick and dirty" test by clamping the high pressure hose and listen for the hiss.
I agree it don't tell you much apart from the pump is working and making pressure.......................pumps tend not to go wrong very often to be fair, but it's the first thing that's changed because it's easy.
 
alldodge

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PS said:
Tried with motor running and turned steering to far left and then right. Pump had no noise during the movement or when deadheaded. Any idea what pump model number I should look for at the auto store?
Click to expand...

You need to determine if it is the pump as camalot mention at the cable end. The steering cable end is what makes the pump fluid move it one direction or the other in the steering ram. If the pump is bad, look for a Saginaw power steering pump. You can get the whole pump or just the pump and remove it from the housing. You would also need a pulley puller.
 
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camalot

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You also have to realize that a boats power assisted steering is not like a car or truck, the actuator will work when load is applied to it (like a shift switch). On land there is not enough resistance to the drive in most cases for the actuator to kick in.
With the engine running and the steering cable pin removed from the transom hinge pin you can use a bar/screwdriver to move the actuator from side to side, if the drive moves the power assist is working.
 
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Steering moves easy when both low and high pressure cables are off pump. Went to NAPA store and it looks like their 81-1083 power steering pump. Same as used on Chev Malibu 3.1 L engine. Does this sound correct?
 
alldodge

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PS said:
Steering moves easy when both low and high pressure cables are off pump. Went to NAPA store and it looks like their 81-1083 power steering pump. Same as used on Chev Malibu 3.1 L engine. Does this sound correct?
Click to expand...

What is the serial number of your engine, or at least the year?
 
alldodge

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PS said:
MERC 3.0L TKS Serial # 1A326853
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The pump appears to be the right one. According to Merc it is part number 866280A04 for the whole pump. In viewing the assembly it looks like you have the right one
 
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I went to AutoZone to look at the pump since NAPA did not have in stock. It has one extra port that would need to be plugged. Any suggestions or maybe I am looking at the wrong pump?
 
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On NAPA web site I see several that might work 811089,811544,81161,811084 do you think any of these will work? Local store does not stock them
 
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The 811544 looks correct except the high pressure hose is on the wrong side. I assume that both have the same drive rotation for the vanes?
AutoZone has 63131 in stock and I went to look at it. If not for the high pressure connection on the other side they look the same. Any suggestions
 
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