honing the hydraulic clylinder?

I am working on reworking my hydraulics. when I took it apart it had the original 3 ring piston and I have decided to replace it with the newer style. when I took the cylinder out there was quite a bit of trash in the cylinder and there are some scratches that are not that deep. I am thinking that I can just hone out the cylinder and call it good. has anyone done this before and how well did it work?

would I just be better off installing a new aftermarket cylinder?

the only reason I am redoing them is once the hyd. fluid warmed up it would not lift. I am almost positive the cylinder and the piston were not the problem to begin with. the gasket that goes in between the cylinder and the top plate was all but missing.

I was planning on doing the same thing, but I also replaced my piston and used the newer rubber o-ring deal. Had some scratches in my cylinder that I might have gotten out, but didn't want to risk it with the rubber. The replacement cylinder worked perfect and I figured the cost was ok, being I don't plan on messing with it ever again.

I recently replaced the cylinder on one of my 8n's and went with the O ring type piston. I had to grind out a bit of the new cylinder tho. if you do that compare your cylinder to the new one. I was expecting a better finish on the inside of the new one, but so far it is working fine.

(quoted from post at 10:03:04 03/13/18) I recently replaced the cylinder on one of my 8n's and went with the O ring type piston. I had to grind out a bit of the new cylinder tho. if you do that compare your cylinder to the new one. I was expecting a better finish on the inside of the new one, but so far it is working fine.

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Mine actually came with the relief already there, I was surprised as I had read they didn't come like that and grinding was needed, as you said.

You know, now I'm thinking maybe you meant the inside. I was thinking the relief on the outside...

(quoted from post at 11:16:27 03/13/18)
You know, now I'm thinking maybe you meant the inside. I was thinking the relief on the outside...

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No, I meant the relief on the outside.

If it don't work out for ya you get to do it again

would I just be better off installing a new aftermarket cylinder?

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If you plan to use an O-ring on the piston then yes, a new cylinder is the best way to go. Unless you can remove all of the scratches in the current cylinder, they will cut up your new O-ring in time.

Steel rings are more durable and will tolerate in imperfect cylinder surface but they do not seal quite as well as an O-ring.

What weight hydraulic oil are you using?

My experience and advice is to forget about honing the old cylinder -I've never seen that work, at least not for long, and you end up having to pull the top cover all over again. I'd spring for a new cylinder as well and do it right the first time. You don't say what model you have -the 9N/2N used a different system -no POSITION CONTROL, and the 8N cylinder has a scallop cast or machined at the 7 O'Clock position on the front of cylinder to allow relief for the linkage to clear from hitting. Might be a good time to at least clean chambers on pump and/or drop completely and rebuild if in real band shape, i.e. full of sludge. You most likely had oil leaking from the worn cylinder and nothing to do with the oil getting warmed up really. A missing gasket would not ne the root cause of your lift failing either. You have an original cylinder and it is time to replace it. It's a good idea to do it all while you have the top cover off and be sure to replace the safety relief valve as well.

Tim *PloughNman* Daley(MI)

If you have an 8N, you must use a cylinder with the scallop relief at the 7 O?Clock position as shown in order for the draft control/position control linkage to clear from hitting the cylinder. The original cylinders had the relief as cast, and some, but not all, new aftermarket ones have the relief machined on them. Here is a picture of an original 8N Cylinder (LEFT) and an original 9N cylinder that has been modified with the relief hand-ground in.

FORD 8N HYDRAULIC CYLINDERS; ORIGINAL AND MODIFIED 9N:

Tim *PloughNman* Daley(MI)

I will be using the traveler brand when I put it back in.

it is an 8n and I have planned to change out the relief valve as well. on a cool morning the hydraulics would work fine to lift a 5 ft. box blade but it would not hold in place. gradually in about 3 hours of work it would not lift the box at all. I let it cool down, lifted the box,as it did that morning, got it put away and off the tractor so I could work on the hyd. I figure it was safe to assume that the temp had a part in this. it is worth noting that I have no idea what type of oil was already in this tractor but it appears that the previous owner recently changed it. it looked brand new when I drained it. I will be replacing it with the traveler brand as that seems to be what most on this forum recommend to use.

(quoted from post at 09:20:59 03/14/18) it is an 8n and I have planned to change out the relief valve as well. on a cool morning the hydraulics would work fine to lift a 5 ft. box blade but it would not hold in place. gradually in about 3 hours of work it would not lift the box at all. I let it cool down, lifted the box,as it did that morning, got it put away and off the tractor so I could work on the hyd. I figure it was safe to assume that the temp had a part in this. it is worth noting that I have no idea what type of oil was already in this tractor but it appears that the previous owner recently changed it. it looked brand new when I drained it. I will be replacing it with the traveler brand as that seems to be what most on this forum recommend to use.

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Loss of lift power and increase in leak down as oil heats up points to a leak somewhere. As the oil thins out the rate of leakage increases. Bypassing could be in the lift circuit itself or could be in the pump. I'd suggest checking for signs of leakage from the cylinder area before doing anything but if you are just going to start throwing parts at it I'd start with a new cylinder and piston as that is probably the most common cause of leak down.

TOH

Try this simple test: Attach a load, like a back blade, mower, plow, whatever. Start engine, engage PTO, raise the load fully UP, then shut down engine with load up. Observe how long it takes for the load to drop down. A good functional hydraulic system will sustain a load UP for days, weeks, months. If the load drops within minutes, hours, or a day, the problem lies within a defective cylinder. It is allowing the oil to escape and thus leak down. If load falls within minutes or so, remove side inspection covers, raise load again, shut down, and with your Mini-Mag flashlight look up to the cylinder and you will no doubt see the oil oozing out of the cylinder. Time to replace cylinder with a new one. Hydraulic oil should be a clearish, honey color. Murky brown or white indicates water contaminated. If oil is OK, not the root cause.

Tim *PloughNman* Daley(MI()