[ccroyle]

Would anyone be interested in offering tips on rebuilding the hydraulic lift? Is it as simple as rolling on a new seal and ‘O’ rings?

I am going to be tearing into my next project of replacing the seal and ‘O’ rings of the hydraulic lift of my 1980 446 once the parts arrive. It appears the fluid drip is coming from around the rod. It made a mess of my mower deck last year and put fancy drips in the driveway during snow plowing. The mower deck is all cleaned up with new bearings, so I want to start out the season right. I could not find info in the forum for a rebuild. In my last topic you all gave me great advice in removing a stuck bearing successfully off of the mower deck spindle.

Thanks,

Chris

 

[Hydriv]

If you consult your parts manual, you will see that the cylinder for the 3 pt hitch and the mid-lift are identical in design. The difference is in the length. Both have a permanently sealed top where the rod protrudes but the bottom comes out to allow the cylinder to be dismantled. The bottom is held in place by the cross-rod and nothing else. Wear and tear on the holes that the cross-rod passes through causes burring and that makes getting the cap off a bit of a challenge.

You need to carefully clean up all the burrs around the holes. You can push the rod all the way to the bottom of the cylinder and then tap it with a hammer to force the bottom cap to move. If you attempt to place the cylinder in a vise, you must be extremely careful that you do not crush the cylinder tube or you will ruin it. Putting it in a vice is not something I would even suggest because of that danger.

The last resort would be to reconnect the hydraulic line going into the bottom of the cylinder and use the hydraulic fluid to force the cap off. Of course, you would want to lay the cylinder in a shallow pan and cover the top of the pan with plastic to control the spray of oil that will result when the cap finally frees itself. All seals and O-rings should be stock items in the inventory of any decent hydraulics shop. They are simple to change and the hydraulics shop can give you some guidance on how best to re-assemble the cylinder so that you do not damage the new parts. Of course, you must finish cleaning up any burrs on the cap and cylinder body. Inspect the finish on the rod for any damage. Pitting, peeling or flaking of the chrome will cause new seals to fail. Once again, the local hydraulics shop can advise you as to what is acceptable and what is not.

Everything must be scrupulously clean and repaired prior to putting the cylinder back together. It's not a hard job but you must pay attention to the details. In the Tech section, there is a service manual regarding cylinders. I suggest that you consult it.