Toddgarage
Well-Known Member
- Joined
- Jun 13, 2022
- Messages
- 80
- Location
- S.E. Michigan
- Occupation
- Construction, welding/fabrication, operator
Here is an update on the manlift. Originally the brakes were dragging and the only way to move the machine was to rev the motor to full speed and travel the machine forward and reverse. It would operate slightly better with cold hydraulic oil, but it would quickly warm up and the problem would return.
The pilot screen filter had green rubbery debris inside and my guess was an internal seal had failed. Some of you also suggested this. But, there was a suggestion that the main relief valve o-rings are also green and to check that first. I did check those o-rings and they were good, no damage and still serviceable. (My guess about an internal seal could only be discovered if the case was disassembled.)
In the process, I drained about 15 to 20 gallons of hydraulic oil out of the tank, and during refill, I didn’t bleed the pump well enough. Or so I thought… it’s obvious now that there was major pump damage to this machine when we got it.
JLG confirmed to me on the phone this machine had a factory/authorized rebuild or refresh. (Some kind of major checklist inspection and repair.) The pump at that time wasn’t replaced, it probably had its pressured checked at the test ports and it passed. Its hour meter was reset and returned to service. We bought it with 1600+ hours and an unknown amount of hours before it’s refresh.
Pump rebuild is underway. I have so more pictures too.
Be safe and have a good holiday.
