Boom drifting

[willie59]

And just to clarify, port relief, some call it circuit relief, same thing just different terminology. Same with main relief, some call it system relief. But the two are distinct and different things.

 

[Toolslinger]

I know on my 310 there are a variety of port reliefs, so keep track of which one comes out of where so you can get them back in the right place.

Having not done one myself, I'm guessing here, but that looks like it's going to be a real stiff spring. I would be looking to take that apart in an arbor press so you've got a good bit of control once you take the snap ring out.

I'm hoping not to need to work on the port reliefs on mine, but I'll be following along for the info. (I suspect I will at some point with the hoe being 50 or so)

 

[Ejp]

W

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

I took the two relief valves apart today it went pretty good except getting to the spring. The caps at the end were extremely tight. The PDF helped show me where it comes together. Surprised me I found no O-rings on the inside the two O-rings on the outside look good, went to my JD dealer and they didn’t have any that size. Tomorrow, I will try to find some and put it back together hopefully but all four O-rings look pretty good note number nine O-ring fit on the cartridge end there was no number eight O-ring inside the cartridge. also, there was no tension on the spring that I had to deal with. All I had to do was unscrew the cap at the end of the cartridge, and the threads released the inside tension.


In

 

[willie59]

See red arrow in attached pic, that's item 6 inserted inside item 10, which has the threads. Item 6 slips out of item 10 and should expose o-ring 8 and washer 7. I wish I could figure out a way to post that diagram here so everyone could see what we're talking about.

 

[Toolslinger]

Here ya go. Save it as a jpg, and it drops in nicely.

 

[Ejp]

Update on the 400 backhoe, I have good news and bad news, the bad news is I have alot of tools to pick up the good news is I have learned a lot. I never expected the old backhoe like that to totally stop drifting, but I am super excited with the results. I found the last few O-rings this afternoon and got it all back together this evening. no visible leaks and the boom drift is hardly noticeable compared to before. I would say it stays up at least 10 times longer, that’s plenty workable for me so happy. All the thanks goes to you guys and my wife for tolerating me and her help. I am really appreciative of this form. Thank you so much . It feels funny, not posting any pictures.

 

[willie59]

Any further drift is likely from the valve spool itself as well as the valve body bore is worn. Again, that thing's like 60 years old, and replacing it is likely impossible.

 

[Ejp]

Willie, I was wondering, do you suppose there could be some air in there? I did disconnect altogether six hoses or at least five because I had to take some of them that were in my way of getting to other getting into the other ones. I wonder if there is air in there maybe it would take time to work it’s way out at any rate I’m gonna see if I can get a chance to Work it a little bit tomorrow and that might be it for a while because deer season starts Saturday .

 

[willie59]

It's always possible to get an air pocket in a cylinder when lines are disconnected, but rarely is it a problem, if anything may get a little bounce of the boom, but nothing to really worry about.

 

[Ejp]

It's always possible to get an air pocket in a cylinder when lines are disconnected, but rarely is it a problem, if anything may get a little bounce of the boom, but nothing to really worry about.

Willie would you happen to know where I could copy a PDF repair manual for my John Deere JD 400 wheel loader?

 

[willie59]

I wouldn't have a clue about that.