3 point hydraulic rebuild

[wmonroe]

My 961 has had a sluggish 3 point lift at low rpms and it drifts down fairly quickly once the engine is off. I’ve made time and decided to start tearing into it to see what’s going on. The oil in the hydraulic sump doesn’t look very good (appeared ok in the dipstick) and there was a slime/jelly like coating on everything inside. I’m in the process of getting that cleaned up but my main question is the 3 point lift cylinder has some minor scoring but I don’t know if it is acceptable or if the cylinder has to be replaced. I can’t feel them with my fingernail.

 

[ptsg]

If you don't feel it with your fingernail, then it's not bad enough to worry about.

From the pictures, looks good. I would go with it. :thumbsup:

 

[Ultradog MN]

A couple of things for you to consider:
A new cylinder costs about $600 iirc.
Your hydraulic pump puts out about 4 gallons per minute. Your lift cylinder holds somewhere between a pint and quart of oil.
You have Plenty of capacity to overcome any leakage.
Don't forget to replace the cam follower pin and adjust your linkages while you have your cover off.

 

[RickB]

Hit it with a 3 stone flexible cylinder hone. You have it apart, give it all the love you can.

 

[wmonroe]

I’ll give the hone a try and see what it looks like. Good to hear that no one thinks it’s a complete loss, wasn’t looking forward to dropping the money on a new cylinder. I have the I&T manual and will make the adjustments prior to reassembling.

 

[Soundguy]

I've honed ones worse than that.. and honed them more or less out of spec to get a scratch out. Big thing is to get it so it won't cut an oring. then use a real CNH oring.. they are fairly fat.. and even on out of spec ( slightly) cyl's they go in tigs and seal ok.. and as said.. you have excess volume from the pump to play with to handle incedental leaks... hone it so it has no sharp edges.. clean up good and go with a fat oring from cnh

 

[wmonroe]

I’ll hit it with the hone hopefully one night this week and then maybe get the cover reinstalled this weekend. This is turning into a fun but time consuming project. The only part of the tractor I haven’t drained the fluid and opened up is the engine.