Hydraulic cylinder leak

[joes_427_vette]

I bought an older western 5' snow plow off the internet. It must have been made for Kubota because it had a serial tag with Kubota stamped on it. The turn cylinders were 2 1/4" in diameter and featured a weld on backing plate. I took it to a hydraulic shop. They said heat the end and pull the shaft out after removing the snap ring OR for 75 big ones they would take it apart. Seals are 25. Well I heated and pulled, and pulled some more. Finally in an act of desperation I stuck it in the bandsaw and cut the end with the backing plate off. Now it came apart backwards and after a close inspection realized this is the only way to repair the cylinder.
Returning to the hydraulic shop for seals the guy smiles and says I see you figured out how to get it apart ( after seeing the barrel cut off ) . We located the 8 seals which cost $8.04 with tax. I assembled the ram, welded the backing plate and after it cooled replaced the seals and snap ring.
I guess no one really likes to give away their secrets in the repair business. I was ready to replace both rams but couldn't find the correct length for the mounts. I really like the mig welder for making repairs.

 

[JC-jetro]

Any pics by any channce? Nothing like see the actual components, before and after.

 

[scott_vt]

Afternoon Joe,
Gee Joe it would have been nice if they told you that up front Would have saved you a bunch of head scratchin

Good job !!!

 

[joes_427_vette]

After taking the cylinder out of the barrel I noticed the steel ring around the cylinder that stops the ram from going too far. While waiting for the seals I thought I would weld the end cap back on and grind the surface smooth. I thought in my infinate wisdom that the steel ring could be compressed for assembly as it had a quarter inch gap on the ends. Well.... I was wrong ! I had to cut the end off, insert the cylinder and reweld the end cap. It appears there is a section approximately 1 1/2" in the barrell that is the same diameter as the cylinder acting as a guide. There is also a guide at the far end via a cast iron removable sleeve. So living is learning and now I know about disassembly and assembly. I guess I used the ring compressor too many times to believe it was a universal application. I have included a picture of the components for reference. It is true what they say... you can learn something new every day !

 

[JC-jetro]

It is true what they say... you can learn something new every day !

Ha....capiche

That's more like it. I wished there were some kind of threaded bushing or type of fitting at least on one end so the end could be removed for seal replacement without going through all you have done. good job.

 

[kmdigital]

Ok, dumb question. Why did you have to remove the ram for repairs? The seal fits in the front, and is held in with a snap ring, and should have been replaceable without removing the ram, to my way of thinking. So why remove the ram?

 

[joes_427_vette]

And .... here is the dumb answer. If you look closely at the parts layed out on the floor you will notice a round cylinder made of cast iron approximately 5/8 " thick. Part of the back side is smaller to hold the 4 seals and 2 wiper rings in place. It also has a groove in the front for a final oil seal. The snap ring holds this in place. The question is how do you get this cast iron retainer out to change the seals. After 20 plus years of rusting in place against the barrel there is no place to hook on to pull it out. After I sawed the cylinder and removed the contents from the rear I tried to remove it with a long chisel. No such luck. I had to soak it in penetrating oil and after a few clouts with a brass drift it moved forward. I cleaned the interior surface the best I could and ground the retainer slightly so it has a clearance to slide out with very little persuasion.
I discussed this with the local hydraulics expert and came to the conclusion this was an economy version built as cheap as possible for single action rams. There is no way to repair this particular system without desperate measures. Many of them went unrepaired and were tossed in the scrap bucket. This was my intention to go with new replacements but I didn't have the room to add the 2 1/2 " longer cylinders. I could have modified the mounts and stretched the A frame but I wanted the blade of the plow as close as possible to the front tires.
The complete seal kits ran $8.08 for each cylinder. As the ram was in good condition it should be a lasting repair. I thought I would mention it on the forum in the event someone else runs into the same problem.

 

[kmdigital]

Ok, I suspected that was the case, i.e. in other words you couldn't get the seal and components out the front until you removed the ram so that you could drive it out from the rear.

One thought that might have worked, depending on how badly the seal leaked. You might have been able to connect the hydralic cylinder to a pressure source, such as your tractors hydraulic system, and after removing the snap ring, pressurize the cylinder, drive the ram against its stop and keep the pressure on. The high pressure might have forced the seal and components out if the seals didn't leak so badly that you couldn't build enough pressure. To reduce the leakage you could have put some heavy weight oil in the cylinder first also, and kept the ram in the down position so the oil stays at that end.

Obviously, with this method put a bolt or pin in the ram's clevis to prevent parts from flying away, and do it somewhere that an oil mess won't matter/is easily cleaned.

 

[joes_427_vette]

We tried a dozen different approaches but the rusted collar would not move. The seals are the same diameter as the cylinder. If you noticed on the picture the front of the barrel is 1/2" larger in diameter. This is where the seals are located and the edges just wipe the cylinder as it moves. There is no way to put pressure on the collar or the seals for that matter. The leak was coming from the wiper seal in the collar. It sits in a snap ring type groove and through age just become brittle. It would drip under pressure, nothing substancial, but it bothered me and before I sand blast the plow and add the paint I wanted to make sure everything was in good working order.
I toyed with the idea of drilling two holes in the collar and tapping them so a puller could assist in removal at a later date. As this is made of cast iron I wasn't sure how it would work. I just ground the edge for a less restrictive fit. The four seals and two end caps are forced together when inserting the collar. This will prevent a leak on the outer edge of the collar.
I'm back in business as they are function properly.

 

[whitetiger]

This style of cyclinder is not that uncommon at all. First you remove the hyd fitting from the barrel. Next move the shaft in till you can see the wire ring in this port and pop it out of its groove and off the bottom of shaft. Now just pull shaft from barrel. Remove snap ring from the top of barrel and remove ring with a slide hammer and expanding 2 or 3 arm puller. If it is rusted you have to heat the ring and let it cool to break loose the rust.
To reassemble wire ring to shaft, install shaft [with ring laying in the bottom of barrel]and push in till you can see groove in the oil port, turn cyclinder on end[ shaft down] and pop ring down over the shaft into its groove.