1755- got remote valves on...there's a problem

Randy-IA

Member
Howdy all, I got the remotes on and working on the 1755, new hoses, old couplers. One valve works perfectly. The other has a problem.

One port (base end or rear port) will not flow enough oil. I've sort of diagnosed it to be the interlock pin is broken or the plunger is stuck. That's what the White technical service manual guides me to. But, there are two other possibilities too. The first being the spool itself, I may have installed it with the arrow up (I don't think so, but I can't get a good look at it with it in the tractor), I don't know what kind of problems that causes though, and the second being that when the check ball fell out while I was installing them I may have put the collar retainer back in upside down (again, I don't think so, but it's always a possibility) The channel in the outside of the retaining collar holding the pin would be on the ball end to line up with the interlock port to allow oil flow through it. Near as I can tell that's how it works anyway. These port fittings are impossible to put on or remove while the valve is solidly mounted on the tractor; the new 90° hose ends that were put on the new hoses weren't the short elbow type like before, these are a quarter inch longer hanging down, this causes some interference with the axle mounting bolts on both ports. No leakage now, but that might be only a matter of time.


Can these internal workings be worked on with the valve spool in the neutral position without draining the hydraulic fluid? Or is there still a path for the fluid to drain out at the valves?

I'm worried the fluid will get contaminated out here in the gravel drive, even using the new buckets with all the flying insects and dust coming off the road when folks drive by. That's some pricey stuff as we all know, and this is all new fluid. (Deere Hy-Guard)

Naturally this is the inner valve not working right, near impossible to work on or get to to see. The base end in the rear is probably in a position to work on while still on the tractor, the front isn't even close.

Take em all off and put them back on the bench? And then squeeze the wallet and buy new oil...

Any thing I may have missed? Any suggestions? Shortcuts?

Thanks!
 
Couple of comments, always install the remotes with the hydraulic fittings installed already so that you dont lose the check ball. Those 45degree o-ring to JIC hydraulic fittings cost about $2 at the hydraulic store, so throw the old ones away.

Unless the tractor is running, the only oil you should lose when pulling the remotes is what is in the valve itself and the hoses, so oil loss to remove them and reinstall them correctly should be minimal.

What did the plunger (think you called it the interlock pin) look like when you pulled it out to replace the o-rings on the seats? That thing is hardened steel, I cant think of a way it could get broken in this system. Try pulling the plug out of the back of the remote, pull the spring and poppet. Find a screwdriver the size of the steel shaft on poppet and insert it back into the hole and push on it. You will be able to tell if you can push the plunger and move the opposite side poppet off of its seat and whether it returns to its proper position.

How did your poppets look?
 
Hi Mitch, The coupling hoses are a done deal, already made and much too expensive.

As for what I mentioned in my post; those are just the possibilities the service manual gave me. I know that most won't apply here.

I took one of the valves I replaced apart to see what was inside and what I was dealing with. I wasn't able to take the spool apart because I could come up with a combination of punches that would break the retainer free. I'll have to either by the spanner of keep pondering on that. Or I just might take it to the agco dealer and let them take it apart and put new o-rings in it...then just swap it back onto the tractor.

This entire project is me throwing money at something I didn't understand. But I'm working on that part. I got the two replacement valves for less than half of what the local salvage yards wanted so I'm good with that part too.


The original ones I took off are likely just needing a rebuild, after taking the one apart I saw what I supposed was good parts; not a lot of metal to metal wear (just some normal brightening where they contact), no scoring that I could see inside the bores, the poppets still had little sealing ridges around the cone face, the springs looked good and felt good (not a great indicator since they are seriously strong springs), the metal balls all looked ok, just the o-rings seemed to be needing replacing, they had taken a set with a flat face. Overall, I would call the one I took apart good as soon as I replace the 0-rings. At least nothing abnormal jumped out at me. Normal is relative since I don't know what new looks like.

The used one I put on the tractor that is being a problem I haven't had apart yet. I doubt the plunger is bad, but there is a the likelihood that the poppet in the spool is bad. That would leak oil past the poppet when it's closed pushing the cylinder out (I think from reading the manual) The plunger below the spool is only to allow oil to return as the cylinder moves in and out. It's doing that (at least in one direction) so it's doubtful that's the problem.

I was hoping to fix it while it was still on the tractor. But the solutions in the service manual are all over the place. I don't have the resources to check all those suggestions. But if you think I can remove the bottom plunger without losing massive amounts of oil onto the ground I think I'll try that first just eliminate that possibility before I drain the system and take the valve all the way off. I can just strain the oil before I put it back in. But this won't happen today, I'll need to wait til Monday to get all the new o-rings I'll need to use since I'll have it apart.

Thanks for the info. Sorry I write so much but I believe in being thorough with my descriptions and being succinct isn't in my blood.
 
Couple of things I learned doing this. After trying to get the oily valves on three times I improved the process as best as I could each time having never done anything quite like this before. With the tire and all the levers and the three point lift arms all in the way maneuverability in that area is tight for a big guy like myself. And twenty pounds of valves and hoses might not seem like much but at arms length they get heavy fast when you are trying to get three or four things to mesh at once. Each time I was loosing at least one of the innermost o-rings and backup washers. My first try went easy...I got it all tightened down and was trying to put the inner pin in the lever when I saw a backup washer on the axle...found two actually and had to take them all the way off again. Second try, same thing.

So this what I learned;

One, bolt the valves lightly together with the rear mounting bolt before putting the gang on the tractor. Leave all the other bolts in place too, as the manual states.

Two, as Mitch instructed, have the hoses already on the valves before putting the valves on the tractor.

Three, put the holding pins (if they are c-clip retained) in the spool and slide the levers to about a half inch from the end of the bar they ride on and hook the spool pins under the notches of the levers at the same time as putting the end plate on the bar. It was easier to hold the pins centered in place with grease before trying this. If your pins are cotter keyed this isn't as important, but putting those little pins and tiny c-clips on under the floor pan is frustrating to say the least.

and last but not least - in my case anyway, the most important: make certain the tiny little arrow on the lever end of the spool points down (towards the ports). Why? Because the manual says to.

I believe (but didn't prove it this time) that my problem with the base port not flowing oil to extend the ram was the result of me not paying attention to this one short sentence at the end of the assembly process of putting the valve back together. The two sensor holes in the spool have to be open to the return oil in order to pressurize and move the return poppet off it's seat to allow return oil to flow back to the hydraulic tank. After I got the offending valve back off and the re 0-ringed valve back on I saw that I had the arrow pointing up.

I made certain the arrow pointed down on the valve yesterday and it all works great now! I was having an issue with the original valve that I had taken off the first time, it wasn't self cancelling then or after getting it back on yesterday. (As I said before, I put all new o-rings in it). As it turns out I had turned the valve detent pressure adjustment all the way in which raises the pressure to self cancel beyond what pressure is available to overcome it. I turned the adjustment counterclockwise till it stopped (about a quarter turn) cycled the cylinder, it self canceled, turned it slightly clockwise and check, and keep doing this until it struggles just slightly to self cancel and then turn it back ever so slightly until the struggle goes away. This was my own idea since I don't have the test equipment to adjust it to the recommended pressures. I figure that with a 1,700lb bale on the bale forks that this should hold and not cancel too easily (This circuit is used mostly for my hydraulic top link).
 

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