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JLG 450A - valve ID

CaptSkinny

New Member
Joined
Aug 28, 2020
Messages
1
Location
Portland, ME
I bought a JLG 450A that I think has some valves in the wrong position, or an incorrect valve installed. But the JLG part numbers in the manual don't match the numbers printed on the valves, which are Hydraforce part numbers (JLG's manufacturer for the OEM values), so I can't verify that they're in the right place. Could anyone tell me what manufacturer (Hydraforce) part numbers should be printed on these valves in the main manifold? :
  • Swing: JLG# 7023914 in manual
  • Upper lift: JLG# 7023922 in manual
The JLG manual gives separate part numbers for these valves, and price is very different, but I have the same valve in both positions on my machine: SP08-47D printed on it. That suggests to me that at least one of them is the wrong valve, and might be responsible for some of the strange behavior of the lift (like telescope extending or retracting a foot when upper boom is raised or lowered).

I've been able to piece together that maybe the Swing valve should be SP08-47C instead of the "D" variant that's there, but I can't confirm. The difference between C and D variants is the neutral position: with C ("closed center") flow is blocked from all ports, and with D ("motor spool") flow is allowed in the neutral position. Not sure if that helps identify what goes where.
 
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