Backhoe Backhoe Control Valve

JoelD · Apr 20, 2019

Hope your better soon. Once you figure sizes you’ll be good.

sodamo · Apr 20, 2019

JoelD said:
Hope your better soon. Once you figure sizes you’ll be good.

Yea, me too
I think you got the sizes. I had the black O ring size, not the other one.
Sadly, what I know about hydraulics wouldn’t buy me a cup of coffee.

wdchyd · Apr 25, 2019

Hey Guys, does this Nimco hyd valve look like yours? The tag numbers are different than what is posted here.
I am making up prepackaged replacement seal kits for these as we have had several like these come in for repairs the last few years. Usually we just match them up out if our normal stock, but this should make it easier. The OEM yellow seals used on the spools are gummy and I’m thinking whatever material they used from Nimco is not compatible with normal hyd oil, we have a better seal in mind.
Thanx

sodamo · Apr 29, 2019

Thanks, Bill. Sounds like that might be helpful. I worked on mine without dismounting from the backhoe so couldn’t read the plate.

sodamo · Apr 29, 2019

Thanks to the info from JoelD I think my valve is back in service, at least no apparent leak on top side. May be a drip on bottom, not sure.

I used these

Apparently the white orings don’t last even if ‘new’ the ones i put in last week were mush already.

Wish I had replacements for the nylon washers.

BTW, I was able to replace these orings without dismounting the complete valve. Just loosened the 4 mounting bolts and worked it right on n the hoe.

Anyone know a good, reasonable cost replacement for the stabilizer boots? Mine are pretty shot, but $40 is not reasonable.

sodamo · May 1, 2019

Used the backhoe today, about 20+ ft trench along the driveway.
Sadly, valve is still leaking, but from the bottom. Top is good. Not sure what needs replacing for that. Anybody done a complete rebuild of all rings and seals?
Will just suffer thru it for now and just keep hydro fluid topped off.

VictorW · May 2, 2019

The bottom uses the same size o-rings and white nylon backup washers. It looks like a copy of the top other than the centering spring it attached to the end of the spool. The caps on the bottom don't seal the fluid. They just house the centering spring. You may want to take off the entire valve assembly for these because it would be much easier than trying to do it all upside down.

wdchyd · May 2, 2019

VictorW said:
....................You may want to take off the entire valve assembly for these because it would be much easier than trying to do it all upside down.

X2.........do it once, do it right

sodamo · May 2, 2019

VictorW said:
The bottom uses the same size o-rings and white nylon backup washers. It looks like a copy of the top other than the centering spring it attached to the end of the spool. The caps on the bottom don't seal the fluid. They just house the centering spring. You may want to take off the entire valve assembly for these because it would be much easier than trying to do it all upside down.

Thanks, Vic. Yea, I don’t always do well upside down.

sodamo · May 2, 2019

wdchyd said:
X2.........do it once, do it right

Gawd, hope I grow up to be as smart as you

VictorW · May 3, 2019

Thank you for posting which o-rings you used. I was hunting for some because I think I'm on borrowed time. The bottom o-rings won't be to bad other than taking the valve assembly off the frame and all the hoses. I marked mine because they can easily get mixed up. Be careful when removing and installing the screw that holds the centering springs on. If I remember right, they are little 5mm screws. Mine came out pretty easy but don't torque them down to tight. They're similar to the ones holding the centering spring caps on.

JoelD · May 4, 2019

Yes for me bottom was same white o-rings and white sweeper washers. I’ve reused the nylon washers without issue. Agee the stock white o-rings are junk. Not sure why. Glad it looks like you’ve found an alternative source for o-rings. I guaranty the stock o-rings on bottoms are all mucked up. Good luck. Ps I used a piece wood as a lever under the valve body to pry it up as I installed it so I could line up the holes to bolt it back into the frame. Valve body is very heavy. I’d say around 50# give or take.

sodamo · May 5, 2019

That’s good to hear, Joel. Would like a size/source for the nylon washers. Fortunately I had a couple extra, but I’ve also broken 2, so will have to be extra careful. Heavy indeed, last time I took it out, very frustrating getting it back in.

JoelD · May 5, 2019

The tricky part with nylon washers would be to get the thickness right. I bet you could fairly easily measure with a digital caliper. I’m at different house I’ll measure when back at the machine as I have a few spares.

JoelD · May 26, 2019

Sodamo, did you fix bottom o-rings?

sodamo · May 26, 2019

Not yet, Joel.
Have backhoe off tractor right now, but I hope to get to the valve this week.

sodamo · May 26, 2019

Anyone find the nylon washer replacement?

VictorW · May 26, 2019

sodamo said:
Anyone find the nylon washer replacement?

You and JoelD mention the white o-rings, probably a polyurethane type, getting gummy. Mine have black, 2005 KB2375, and I assume a type of rubber rings that have held up well. I looked on the o-ring sites and haven't found the nylon back up washers yet. At least not in anything smaller like ours are. I need to take mine apart to get good dimensions. So still hunting for a place that has varied sizes to be able match up.

sodamo · Aug 10, 2019

Finally got opportunity to work on valve. Changed out the lower O rings.
They all looked like this or worse. These are the urethane rings.

I was careful and was able to reuse the nylon washers.
Anyone who has done this, is this it or do I need to replace something else?

Didn’t get chance to remount and test, maybe tomorrow.

VictorW · Aug 11, 2019

The o-ring is the only seal with the nylon washer to back up the o-ring and possibly work as a debris wiper for the spool shaft. When I had to work on mine, I had top and bottom both apart and was able to remove the spool and check for any scaring that may tear up the o-ring. I would've polished with 1000 or higher sandpaper but wasn't needed. Your valve blocks have some rust on the outside. I sprayed mine down with fluid film which has worked well. Not sure why they used the urethane washers when they're not made for this type of application. You should be good to go with the black rubber o-rings. I'm still looking for the nylon washers. I found everything but the right ones.