Help! Stumped on IMCO steering!
 

Well I've stumped IMCO, Teague and Eaton on my steering system problem!
My dual-ram IMCO system gets progressively harder to steer, the more you turn the wheel. On startup, it's free. After four turns it takes Popeye to turn the dang wheel. Tonite I drained the pump, blew out the cooler, and checked the entire return line. Re-filled everything, and no difference! I'm open to any suggestions!! Pull the rams? That's next I guess...

Any hydraulic helm experts out there? Falcon?

Re: Help! Stumped on IMCO steering!
 

sure you have the lines hooked up right on the rams, do the rams move in & out ok with the lines off, also you might want take the pump apart and check it

Re: Help! Stumped on IMCO steering!
 

This does sound strange. If you have the air out of the system, I would check that the system is actually flowing oil.

Remove the return line at the reservoir for the pump (not the accessory reservoir if you have one). Cap off the return fitting on the reservoir. Route the line over the top into the cap area of the reservoir and secure it somehow so that you can see the oil returning. Now you can run the engine and watch the flow returning to the reservoir. Let me know what you find.

Re: Help! Stumped on IMCO steering!
 

Falcon, good idea. I'll try that tonite. Fluid is definitely flowing back into the reservoir, but that'll show me how the flow changes on the third or fourth revolution of the wheel. Have you every heard of one of these Char-Lyn (Eaton) helms going bad?

When I took the low pressure (return line) off the helm, no fluid drained out. (The system was cold, engine not started yet, btw.) I turned the wheel back and forth a couple of times and fluid started flowing out. Not much, but it appears to flow good from there. I thought for sure that's where I'd see a restriction.

Thanks for all the help!

JimG

Re: Help! Stumped on IMCO steering!
 

Could a restriction on one of the ram's lines cause this? My next step is to crack those lines...

Re: Help! Stumped on IMCO steering!
 

To check the lines to the cylinders, remove one line at a time from each cylinder and turn the wheel in the direction that should put oil to that line. Do this "without" running the engine.

Is this a new install/repair or a working system that went bad?

Re: Help! Stumped on IMCO steering!
 

I suggest you find a good hydraulic shop that can test both your pump and helm unit. You can spend a lot of time trying to find this besides the mess if you are not careful. Spool valve in the helm sticking could cause this. Does it matter which way you turn it before stiffness sets in? You have condition of pump going bad also. Pump having pressure but NO flow would cause this. Only way to tell is with a tester. Helms are pretty trouble free usually but anything is possible. If not one of these I would say a hose collapsing on the inside possibly.

Re: Help! Stumped on IMCO steering!
 

The system is about 4 years old, not run very much since then. Approx 100 hours. The previous owner never saw this problem. He said it was always stiff at low speeds. I thought I was seeing this symptom, called IMCO, and upon their advise I drilled the orifice to 11/64's. Didn't help. That's when I started troubleshooting.

It doesn't seem to matter which way I turn it. Pressure builds and it gets stiff. The power steering pump is new. I replaced it a couple of weeks ago.

Thanks!!!

Re: Help! Stumped on IMCO steering!
 

WORSE NOW!!!

Ran the return into the top of the tank, started motor. Good flow at first, (when the wheel is easy to turn) then dropped to about 1/2 to 3/4 flow. Got stiff.

Re-traced all lines. Checked out ok.

Then we disconnected the rams and turned the wheel. The valving is sort of weird, but IMCO says it's normal. The give side doesn't start really pulling until the "push" side fully extends.

Then we cracked one of the fittings and manually pushed the ram in. I think we got air in that way. So now I have to figure out how to bleed the system. Then go back and start trying to troubleshoot the "power steering" part of the problem. Could a bad power steering pump valve cause this? The system feels like there's no power assist at all.

IMCO says it may be the helm pump itself. $450. It's just a tractor part so I may go to an ag supply and see if I can get a deal on one.



I'm about ready to find a dumpster!

VERY FRUSTRATED!!!

Re: Help! Stumped on IMCO steering!
 

Check to see if the rams are mounted symetrically and on center to the drive pivot point. You could be bottoming out or fully extending one ram before the other.

G

Re: Help! Stumped on IMCO steering!
 

Steering helms are not to technical. It is a hydraulic pump with the drive connected to the steering wheel via a spring centered valve. If you have an idea of what a gerotor type pump is it will help. You have the pump section connected to a spool valve held in a centered position with a spring. The more force you put on the steering wheel over comes the spring centering presssure allowing the spool valve to open ports for the oil to flow to the cylinders under pump pressure creating hydraulic assist. Probably not the best explanation.

You could tee in some gauges in the cylinder lines and see if you get full pump pressure. You should see full pressure on one side and low return pressure on the other. Another gauge in the pressure line from the pump to the helm would be a good reference for the pressure side on cylinders.

Just remember that just because you have pressure does not mean you have flow. Two different parts of this equation.

Low return flow you mentioned would be normal if the cylinders are bottomed out. When they are moving you should see full flow.

http://hydraulics.eaton.com/products/steer_main.htm

Good luck!! :crazy:

Wanted to say thet are not the easiest to trouble shoot with out the testing equipment and some expierance with them. :p

Re: Help! Stumped on IMCO steering!
 

I know this is basic, but is there a filter in the system? It should be somewhere in the high pressure pump line to the helm. If there is one and you haven't checked it, remove the internal filter cartridge, put it back together and retest.

If the flow goes down, your problem shouldn't be in R-L lines, connections, or cylinders. It's the pump-filter-helm-return circuit and related parts that should be looked at. With the cylinders hooked up and just turning back and forth the return back to the reservoir should be fairly consistent (slight volume need differences due to steering cylinder geometry) and if it did change, it should return to normal when you stop turning the wheel. From what you said, I assume it won't return to normal until the engine is stopped for awhile and restarted?

I wouldn't worry too much about some air in the cylinders until you diagnose the problem. If you have a considerable amount of air in them, you can check an earlier post that I had about filling the lines and cylinders without starting the engine.

As far as just getting a "tractor" helm, good luck finding the right one. See the page that Paradigm Shift referred to. There are many types and sizes. IMCO would know exactly the one to use (a Char-lynn/Eaton 4 or 5 series, no feedback, open center, 120cc or 7cu.in. per rev).

Re: Help! Stumped on IMCO steering!
 

Thanks for all your help guys!! I think I found the problem. I bought a new PS pump and swapped the check valve into mine. Steering feels very consistent now. It's still a little stiff, but maybe when I get the air out it'll get better.

Falcon, yes there is a filter. I've replaced the element, but for troubleshooting my last problem I removed the element altogether.
Thanks again for all your help!

Re: Help! Stumped on IMCO steering!
 

Ron at IMCO gave me the ag part number. My tractor supplier should be able to hook me up.

But, I think I may have it licked. I want to run the boat for a while and see if the steering effort gets easier. I did notice it got a little easer with RPM now. Before it didn't matter. Thanks!!

Re: Help! Stumped on IMCO steering!
 

Glad to hear your getting closer..

Dick

Re: Help! Stumped on IMCO steering!
 

Good to hear it's working ok. Rpm's help because of the increased flow, the increased effort is when you turn the wheel at a rate that there isn't enough output from the pump to keep up with the output to the cylinders. The "manual steering check valve" will then operate to still allow steering at a higher effort, like a sea-star type helm. Good luck!