Lx865 - Boom lock out

[tsm]

I recently bought a beat up NH Lx865 and have been in the process of getting it back up to snuff. When i got the unit it was in sad shape. The pedals and brackets were rusted away, the linkage all rusted solid, chains sloppy, hoses worn etc. Well, I stripped down the unit , repainted, new decals, replaced all the spherical rod ends on the linkage, replaced the dampers, replaced all the hoses, repaired parking brakes, repaired "safety circuit" wiring, and made custom foot pedals, shafts and brackets out of stainless steel, chained all filters and fluids. Today I finally got her all back together and was doing a test run, at which time I found that the boom does not lock when the seat belt is removed, driver is off the seat or even if the key is removed from the ignition. To verify, I even unplugged the solenoids. The foot pedals still allowed the boom to lower. Obviously this is NOT and acceptable situation. My question is would air trapped in the system cause this hazard, do I just need to cycle it more to work the air out, or do I have to look a control valve overhaul? Heine site , I should have done it when everything was apart, but felt the problem was in the bypassed wiring.

 

[AaronS88]

Unscrew the solenoids out of the control valve and see if the ends are still in them. Someone may have gutted the solenoid to bypass them. Some of the Lx865's only had a safety on the boom and not the bucket, and some had a safety on both. A New Holland dealer should have a solenoid in stock to replace your faulty part or parts. The solenoid is a mechanical lockout on these control valves, so it is not air in the system. When it is not energized a plunger is extended into a slot on the spool not letting the spool slide in and out of the valve body. When energized with 12V the plunger retracts and allows the spool to function.

 

[tsm]

Unscrew the solenoids out of the control valve and see if the ends are still in them. Someone may have gutted the solenoid to bypass them. Some of the Lx865's only had a safety on the boom and not the bucket, and some had a safety on both. A New Holland dealer should have a solenoid in stock to replace your faulty part or parts. The solenoid is a mechanical lockout on these control valves, so it is not air in the system. When it is not energized a plunger is extended into a slot on the spool not letting the spool slide in and out of the valve body. When energized with 12V the plunger retracts and allows the spool to function.

Aaron: Thanks for the tip, sure enough the previous owner must have bypassed plungers. When I removed them they appeared to be removed with a cut-off wheel. I have a new set on order. Pricey little things.