[CoKid]

Hi. A few months ago I picked up a GMC 2500 with an MDII/E60H and C7.5 plow from a local landscape company. This is my first exposure to this equipment, so be gentle. I was told the hydraulics were fine, but the wiring needed some help. I went through the harness with a multi-meter, and the only thing I could find wrong was the wiring to the motor solenoid was incomplete (white wire laying loose), and it wasn't grounded anywhere. I fixed that, and it is now working, at least 50%. The plow raises and lowers fine, but there's nothing happening left/right. It appears the C solenoid is getting a constant 11V - that doesn't seem right? The motor does not start when either left or right buttons are pushed. I assume it should start for right angle at least no? Also, I can easily move the plow by hand left and right. Meyer's troubleshooting site is a bit ambiguous and incomplete, but implies that it may the crossover relief valve being faulty would cause that condition? To summarize; is it right that the C solenoid should always be energized, and what does it mean that the plow is easily moved side to side by hand?

PS: It's snowing hard here in the San Juans, and my snowblower's main shaft just broke, so I'd really like to get this thing working. Which leads to a third question; will it hurt the unit to run it as-is, just enough to clear my driveway a bit? Or will that be hard on the hydraulics?

 

[Mountain Bob]

Sounds lie a controller problem, but possibly wiring also. Unplug all 3 solenoids on the pump, hit "up", see if plow moves left, and see if pressure holds it there.You can have it raised up a but to test this.

 

[CoKid]

Sounds lie a controller problem, but possibly wiring also. Unplug all 3 solenoids on the pump, hit "up", see if plow moves left, and see if pressure holds it there.You can have it raised up a but to test this.

Thanks Bob. Will check that out after work today. Thankfully snow let up for now. In the "it never rains it poors" department, my heater went out late yesterday too - spent a few hours getting that fixed!

 

[Mr.Markus]

I don't remember much about the Meyers. My old farmer boss had a few in the 80s.
The head gear separates from the plow if I'm not mistaken. He would quite often Attach the hoses together when separated. Once or twice he would forget to rehook the angle cylinders to the pump and get the side to side flop.

 

[CoKid]

So I did as Mountain Bob suggested, but this controller goes into error state when the solenoids are unplugged, so it won't do anything - pushing any of the buttons with them unplugged does nothing. At the suggestion of a friend, I reversed the green and red cables (B & C solenoids), pressed "up", and the plow turned right, though pushing "down" does not turn left. Anyway, it seems to indicate it's probably a bad controller as you said.

 

[Mountain Bob]

Ya, sounds like it. I should have mentioned, with no power, plow off,truck off, no power to any solenoids, plow raised up in air, plow should be locked, you should not be able to swing it side to side, unless,perhaps, cylinders are full of air.

 

[CoKid]

So the end of this little saga - got a used controller for $120 of the Bay of e, great shape, and with it the plow works fine every which way. Leaks a little from right angle ram, but that's about it. Thanks for the help - the tips above gave me a little more confidence in pulling the trigger on the controller.

 

[Mountain Bob]

If it is a aftermarket ram,you might be able to tighten the nut on the leaking ram. If it is an older Meyer one, probably not, and be careful, the big nuts were junk, and would easily split.

 

[Hydromaster]

The end cap on a one-way ram holds does not hold any hydraulic pressure it Consists of a wiper seal and it keeps ram centered and running straight. the hydraulic seals that hold hydraulic pressure are inside of the tube and fixed to the end of the rod. if they’re leaking you would have to take the ram a part to fix it.

Tightening the nut on the end will not stop it from leaking internally.

 

[Mountain Bob]

Here are instructions if you feel like replacing the seals. Notice what it says about the nut.

 

[Hydromaster]

There shouldn’t be any hydraulic fluid on that side

If you were able to trap that hydraulic fluid in that cavity eventually it would fill up and slowly lose the stroke until the ram completely became hydraulic locked or the hydraulic force would cause it squirt out the end.

there would only be hydraulic fluid on both sides if it is a two-way ram.

 

[Mountain Bob]

There shouldn’t be any hydraulic fluid on that side

If you were able to trap that hydraulic fluid in that cavity eventually it would fill up and slowly lose the stroke until the ram completely became hydraulic locked or the hydraulic force would cause it squirt out the end.

there would only be hydraulic fluid on both sides if it is a two-way ram.

Ya,I used to think like you, until people here corrected me, so I took a few Meyer ones apart, just to know. Not all rams are built the same way. No seal on end of ram, just a stop collar-

 

[Hydromaster]

You’re not correcting me at all.

Tighten it down keep the fluid in there. where does the the Fluid that would’ve leaked now out but is now trapped go?

 

[Mountain Bob]

Oh my.

 

[Hydromaster]

If it is a aftermarket ram,you might be able to tighten the nut on the leaking ram. If it is an older Meyer one, probably not, and be careful, the big nuts were junk, and would easily split.

what you said

Nice wiper seal that helps to keep the rod centered in the tube
What is actually bolted and held in place on the other end of the rod. (Not the tube)
you know the seals that actually hold hydraulic pressure

Fluid is leaking by the seals if you tighten this nut you’re talking about it will not trap the fluid in there and if you did where would it go?

 

[Mountain Bob]

Your quote-
"There shouldn’t be any hydraulic fluid on that side "
You tell me, there always is. Gee I guess it is not a perfect world. Perhaps someone will come along and explain it.

 

[Hydromaster]

The anatomy of a one-way ram
The wiper seal is not made to keep hydraulic pressure in but to keep dirt and water out
as with a one-way ram there is only hydraulic fluid between the five parts seal in this picture and the drilled port. there will be air on the other side going to the wiper seal.

when the five parts seal leaks and the fluid gets on the other side hydraulic pressure pushes it out past the wiper seal.


The wiper seal is not made to keep hydraulic pressure in but to keep dirt and water out
And to help maintain the proper alignment of the rod

 

[Mountain Bob]

I guess you don't get it. On some,like some meyer, there is no seal on the end of the ram.The pressure pushes the ram out by pushing on the end of the ram. The whole cylinder is under great pressure. Other style rams do have a packing on the end. the split ring on a Meyer keeps it from over extending, and ram coming out.

 

[Hydromaster]

I guess you don't get it. On some,like some meyer, there is no seal on the end of the ram.The pressure pushes the ram out by pushing on the end of the ram. The whole cylinder is under great pressure. Other style rams do have a packing on the end. the split ring on a Meyer keeps it from over extending, and ram coming out.

Ive rebuilt hydraulic rams so tell me more.

again on the side of the seals that are bolted to the end of the rod how does the fluid get around thisWhen the whole cylinder as you say is charged with hydraulic pressure there would have to be a second hose/port and the construction of a two-way ram.
Otherwise it would be hydraulically locked With fluids on both sideand the piston. The fluid would not be able to move.

Otherwise the one-way ram are all basically the same there is only pressure on one side of the seals And that’s the side the port is on

 

[Mountain Bob]

You have never done a Meyer, then. Pressure builds in the whole ram, the end packings hold it in, the pressure pushes ram out, as something has to "give". See any inner seals here?