Boom drifting

[willie59]

The best way to replace those spool seals is drop the spool out of the bottom of the valve body, slip a new bottom o-ring on the spool and gently work it down to the bottom, fit a new o-ring in the groove at the top, lube it up good, then slip the spool back into the valve body. Of course that would either involve valve body removal or take a torch and pop a hole in that plate below the valve to drop the spool through

 

[HarleyHappy]

Please be quite careful of getting **** in that valve body or we will be answering other hydraulic issues, LOL.
I already see some white particles around that top seal.
I know what a witch it is to work in there.
Love the torch hole idea to get that spool out.
Just looked at the picture again and man that spool will almost come out as it is, it looks like a slot for hoses is already there, just need a little more.
Good luck, Bub.

 

[Ejp]

The best way to replace those spool seals is drop the spool out of the bottom of the valve body, slip a new bottom o-ring on the spool and gently work it down to the bottom, fit a new o-ring in the groove at the top, lube it up good, then slip the spool back into the valve body. Of course that would either involve valve body removal or take a torch and pop a hole in that plate below the valve to drop the spool through

I was quite careful and not getting any of the junk in the valve, but I did cut the plate which was a great idea and the valve came right out. Unfortunately, it came out a little quicker than I wanted it to, and when the spool came out. It only had one O-ring on it. I’m wondering if the other two are inside the channel I bent a wire Coated wire and run it through there and wasn’t able to snag anything. What have I done?

 

[Welder Dave]

Be careful running any wires in the bore. You don't want to scratch anything. O-rings are cheap and it's never a bad idea to replace them when you have the spool apart.

 

[willie59]

The upper o-ring, where the linkage connects, is most likely fitted in a machined groove just inside the bore of the valve body, o-ring pic will pick it out.

 

[Ejp]

Hi Dave, yes I was careful to use a piece of coated wire and made the coding overlap. The bend. I don’t know if you read my last thread, but my problem I think is only one O-ring came out. It could possibly be that I have lost the other two inside the valve if that’s the case what will happen and what I’ve been able to see so far, there are three number 10 rings and it appears as though one came out the others could have slipped off the spool and possibly into the valve assembly what would happen then where would they go?

 

[Ejp]

Be careful running any wires in the bore. You don't want to scratch anything. O-rings are cheap and it's never a bad idea to replace them when you have the spool apart.

Willie, so you’re saying that the upper O-ring or two that matched the grooves on the spool are inside the wall of this cylinder. How do I get them out to replace them? Hopefully they are stuck in there. I’m so afraid that maybe they’re floating around inside. how do I know if they’re inside or not? I can’t see inside the valve.?

 

[Welder Dave]

If the O-rings deteriorated the pieces might end up in the hyd. filter hyd. or the reservoir. If there's a suction strainer would likely catch any remnants. If a spool were to get stiff or act up could be from O-ring fragments. I'd guess the O-rings are still in the valve body or fell out and you didn't see them. The O-ring you show isn't in really bad shape so I doubt the other ones would be worse.

 

[willie59]

This pic. There will be a groove for an o-ring inside that bore, no other way to do it. You can get a o-ring pick set from Northern Tool, Harbor Freight, or pretty much any auto parts store.

 

[Ejp]

OK I think you guys are finally getting through my brain block. I’ve got to be in Erie Pennsylvania for most of the day tomorrow but before I go, I’ll get my dentist tools out with a little mirror and the pics and I believe that those two number 10 washers are still probably stuck in the wall of the cylinder bore and while I’m in the area I will check out there’s two John Deere dealers there and I’ll look for information on what parts they have available. because that valve is in such a place that it is it’s so hard to be able to see anything , let alone get your hands in there but now that I have the idea I’ll work harder at checking that out. hope to get back in the afternoon or in the morning for sure. thanks again to y’all.

 

[willie59]

Yep, you're getting the idea now. And keep in mind, that's what, a machine that's like 60 years old? O-rings only last so long, and there's a plenty of them on that valve, so you're just scratching the surface of what you're going to have to deal with, might as well figure it out now.

 

[Ejp]

Willie, you must’ve been texting while I was texting so I missed your last text. The one with a little red arrow blowing it up. You can actually see the O-ring in there. I’m gonna sleep good tonight.

 

[willie59]

Well, I've been poking at stuff like that for about 40 yrs now, so I've figured out a little. Sweet dreams.

 

[HarleyHappy]

Consider getting a little scope camera off Amazon or another type place.
The first one I got was cheap, like 20 bucks but for what I needed it for, it was priceless.
I can see, even getting a mirror in there to be effective, it will be extremely hard.
You may consider also getting some long little surgery pliers.
I have a 10” and a 14” set and they come in handy but even then, getting the middle oring will be a challenge.
On those valve blocks, if everything is cleaned well, if you lube up the spool after you seat the o rings on it, I have had good luck just sliding them up and they will seat themselves.

 

[Ejp]

Today I went to two John Deere dealers one in Clymer New York and one in Waterford, Pennsylvania. Bought three O-rings at Clymer for my spool, then went to Waterford and talked to a 30 year tractor veteran. He said my spool only takes two O-rings one at the top and one at the bottom of the spool as they don’t make the acorn nut anymore, he said mine was fine to use as they are made to leak oil if something is wrong inside. He examined it and said that a little chip was no problem. Neither dealer was able to give me any info on my 400 backhoe. The second guy said the valve in front of the one that I already removed needs to be looked at, And gave me a copy that I have sent in this link it goes to a somewhat different tractor but he thinks it’s quite close. He said if that valve is messed up inside that it will cause the boom to drift. He wouldn’t sell me any parts until I looked at it first , that part is the other picture that I sent when I took it out tonight I was surprised and didn’t want to take it down any further until I posted it. He said it is a relief valve. I also took a micrometer and measured the ware places on the spool and it shows .004 of an inch where do you think new O-rings will take up that difference. The camera thing sounds interesting.

I was wondering what kind of lube I should use when I put the spool back together thank you.

 

[willie59]

Yes, that's the port relief that I've been talking about, if it's faulty, or has failed o-rings it will cause the boom to drop. And yes, a worn spool and valve body bore will cause drift, and a backhoe attachment that around 60 years old will most likely have some were of those components, but they would have to be seriously worn to drift as quickly as you're reporting. I say replace those spool o-rings and the o-rings for the port relief, unless you choose to replace it. Keep in mind, if you repair your port relief cartridge, the parts diagram show and o-ring inside of it requiring disassembly of the port relief cartridge

 

[Ejp]

Yes, I’ve heard you talk about the relief valve and I just got the idea that there were a lot of O-rings in there which sounds good if they replaced, but when I open that up and see those two cylinders and it just appeared to me as though there must be O-rings in there under a lot of pressure and I didn’t wanna Take the clips off not knowing what to expect . Do you know what’s in there? I was I have the spool with the two O-rings on it ready to go, but I didn’t want to put them in because I have to hook up the hydraulic lines again without doing some work on those relief valves so do you suggest that I put the spool in and start it or take the relief valves apart and where do I get the O-rings at, that guy didn’t sound all that excited about selling me any and wouldn’t it seem as though if the tractor is that old, which it is that they would certainly have wear on them . You’ve been very helpful and I appreciate it. I’ll do as you recommend. What kind of grease do I use to put all that back together?

 

[willie59]

First, don't confuse terms, like relief valve. There is most likely a main relief valve on that valve body, that's a pressure relief for all functions served by that valve body. What we're talking about is a port relief. Port relief valves only provide pressure relief for a single specific output line. All double acting valves have two output ports, typically noted as port A and port B. If your boom raise is connected to port A, the port relief valve on that side of the valve only relieves port A, has no connection to port B or any other part of the valve body.

Any petroleum based lube for the o-rings, hydraulic oil, petroleum jelly, grease, whatever you have.

 

[willie59]

Don't know if I can post a PDF file, but we'll try.

 

[willie59]

Well, at least it's a link to open. Items 8 and 9 are internal o-rings, would require compressing the spring inside the port relief cartridge, removing the snap ring 12, then release everything without it flying apart to replace those two o-rings.