Willie B
Senior Member
Update;
I took two Port Relief valves out this evening. Not a lot going on. If I get it, a needle in a small port is pressed by a spring. When pressure reaches enough to lift the needle from its seat oil floods the space at the head of a very small piston, overcoming the spring that holds it against a seat.
The needle I mentioned doesn't have a conical seat, only a hole in flat. I think wear, or other miss fit, The needle doesn't always find the hole. Four of eight port relief valves are identical, with the boom lift tightened more. This was tight as it could go. I'd guess it had been attempted before under different ownership.
Seth & I switched reliefs loosening the new crowd out to where the old was, & loosening the new boom just a bit.
Now the boom stays up forever, occasionally the "crowd out" sags, but only a cycle or two.
I'm on the right track. I will order a new crowd relief. I believe they are available. I don't understand why John Deere won't say "use the other relief valve, but turn it up." They could have saved me a lot of trouble.
After removing two valves, finding them to be identical except adjustment, I wondered if the other valves in the stack were available. I asked to speak to Service department at Nortrax.
We discussed the part number: NLA
Alternative part number, shipped from stock pre adjusted to lower pressure: NLA
Can you sell me a rebuild kit?
A: No.
You mean there is no kit for any of 8 port relief valves on this valve pack?
A: No, we list rebuild kits. they're $53.00. I'll have it to you Thursday.
I'm not sure why they couldn't have mentioned that option weeks ago!