Cylinder rod pitting - How bad is this?

[LD1]

Good explaination.
Thanks

no problem

 

[dstig1]

So I tried messing with them a little after work today. Fine emery cloth cleaned up the chrome easily enough. The pitting was pretty minor really. I tried to push them together with a hoes on the port to catch the fluid in a pan. Wouldn't budge. I tried a pipe clamp wouldn't budge. Finally I set one end on the concrete and gave it a few whacks with a mallet. It took pretty decent hits to get it together, and only moved a tiny bit at a time. There is no way to get them back to the open position as is, given how hard they move. I don't have hydraulics handy to hook them up to anything either, and the plow is all apart and half buried in storage, so nothing good to use for leverage.

I expected them to be a bit stuck and then break free and move reasonably, but they don't do that fer sure. Is this normal? I'm not even sure I could get enough leverage with a bar to pull these open again.

 

[yanmars]

I had some rust on my backhoe worse than that, I used 2000 grade paper and oil and then wiped it all off with a paper towel. I have had no leak or problems since.

 

[wdchyd]

If you can't twist the hyd rod with a little persuasion, then the wiper failed allowing rust to form under the wiper ring.....making it stuck

Best to soak them with some kind of penetrating oil and see if you can loosen the gland nuts.....be carefull not to crack the gland nuts as they are cast iron...

If the rods are still stuck, then you'll need to purchase seal kits, disassemble, polish rust in gland and repack....as long as the glands break free then it will be easy fix

 

[PILOON]

The truck plows do have a relief.

It's called a crossover valve. It is usually set around 2000-2200psi and if the pressure exceeds that due to striking an obstical, the valve opens and diverts fluid from one cylinder into the other. Hence the name "crossover" valve.

The reason for the need to "add" one on a tractor is because on a truck, it is built into the power unit. When putting a plow on a tractor that has its own hydraulics, you loose the crossover valve part of the plow setup. So one needs to be added.:thumbsup:

BUT;
The crossover valve only protects when the extended plow corner hit an obstruction.
The retracted side being already 'tucked back' is not protected.
I really wonder if the cost of the crossover is all that valid in that in reality you get only 50% protection.
I plowed for about 12 years with a 3/4 ton truck and honestly found that often the valve was more a pain than useful. (like trying to cut away frozen snow banks)
Probably useful if you plow paved drives lined with curbs in a city environment using hired help. But then you usually plow angled to the curbside and being angled to the curb there is no protection, only if you were pushing snow AWAY from the curb, but then the city will be on your case as well as risking fines.

 

[dstig1]

If it comes to tearing the cylinders apart, I'll just replace them. From what everyone else here said, it's just not worth it vs the cost of new ones. $50 new vs $20 for new seals and a ton of swearing and mess. Makes sense to me.

I was able to pound them to fully closed position with the mallet, but it did not move easy at all. Maybe that is normal. Never dealt with hydraulics this up close....

 

[dstig1]

Piloon - I think it is more to protect the hydraulics than the plow. Impact inward on an extended piston will create huge hydraulic back pressure in the lines and could blow something. Impact on the retracted cyl would cause essentially zero hydraulic pressure buildup as it hits the solid metal stops.

 

[LD1]

So I tried messing with them a little after work today. Fine emery cloth cleaned up the chrome easily enough. The pitting was pretty minor really. I tried to push them together with a hoes on the port to catch the fluid in a pan. Wouldn't budge. I tried a pipe clamp wouldn't budge. Finally I set one end on the concrete and gave it a few whacks with a mallet. It took pretty decent hits to get it together, and only moved a tiny bit at a time. There is no way to get them back to the open position as is, given how hard they move. I don't have hydraulics handy to hook them up to anything either, and the plow is all apart and half buried in storage, so nothing good to use for leverage.

I expected them to be a bit stuck and then break free and move reasonably, but they don't do that fer sure. Is this normal? I'm not even sure I could get enough leverage with a bar to pull these open again.

You can try some compressed air. Hook to the cylinder, but use a regulator that way you can slowly increase the psi instead of blasting all at once. The seals are supposed to be pretty tight , but it sounds like yours are tight-and-dry.

Did any oil come out???

And as others have mentioned, try rotating the cylinder ROD. IT may help. I am sure 2200psi of hydraulics would do the trick also. But it sounds like the seals are pretty dry and if/when they break loose, no telling how bad the leak will be.

BUT;
The crossover valve only protects when the extended plow corner hit an obstruction.
The retracted side being already 'tucked back' is not protected.
I really wonder if the cost of the crossover is all that valid in that in reality you get only 50% protection.
I plowed for about 12 years with a 3/4 ton truck and honestly found that often the valve was more a pain than useful. (like trying to cut away frozen snow banks)
Probably useful if you plow paved drives lined with curbs in a city environment using hired help. But then you usually plow angled to the curbside and being angled to the curb there is no protection, only if you were pushing snow AWAY from the curb, but then the city will be on your case as well as risking fines.

The crossover isnt designed to protect the plow. It is designed to protect the hydraulics. And if you catch something with the retracted side, IF you are retracted all the way, you are against a mechanical stop. Hitting something with that side wont harm the hydraulics anyway.

And if you found that valve to be a pain, it was clearly doing its job. Because they are set just under what the cylinder and hoses are rated for. So you think the plow protecting its hydraulics is more of a pain than blowing a cylinder or hose everytime it happened:confused2:

Trying to clip away a frozen snow bank with the edge....ofcourse it is going to open the crossover. Think about the geometry of the plow. Picture this....a simple bottle jack. With a little hand lever connected to a little piston that pumps fluid: That is basically what the Plow is...The hydraulic cylinder is the little piston pump, and the blade is the handle. Once you reach 2200psi....the valve opens.

And if all you were doing was trying to cut away frozen banks at full angle.....you do know there is a place on the sector and a-frame to PIN the plow in place so you dont have to deal with the hydraulics??

 

[dstig1]

Oh yeah, oil came out. It looked like dirty hydraulic fluid. I may mess with it a bit more tonight. I expected it to be stiff, but it seems more stiff than is reasonable (pounding shouldn't be required...). I'll putz with it a bit more and try air, but I suspect I am "this close" to just replacing them.

 

[dstig1]

I think they are not worth saving. I tried rotating the rod using a 15-18" prybar in each bolt hole, and basically they wouldn't budge. Bummer since they don't seem real bad otherwise.