'99 JLG 534D-9 -45 no reverse or forward

[Robbie Antonson]

First post here. Also do not know how to sign up on forums very well either(do not venture from the 3-4 forums I belong to).

Anyhow, Cummins mechanic(In AK(1980'S), worked on it all, Boats, Gens, HE, Tractors, ETC) in the past, now work for my self on Toyota Land Cruisers. Anyhoo.
My BIL wanted help with a 534D-9 that will not go into forward or reverse. the boom will lift up and down, extend. But the Forks will not rotate by the button on the Joy Stick. Do not feel this related to the Fr/RR issue.
Things I have checked. Power was routed out the approbate wires on the switch when The Parking brake switch in it positions(based on Wiring diagram). Yes, no start when engaged, no power to the Forward and reverse
solenoidConnectors. when engaged. When not engaged, Engine will start. Power to Solenoid connectors will happen when the selector switch is approbate location. Ground is good to the Solenoid connectors. I have not been bold enough to try and
engage the FR/RR solenoids with power to see if the TH will move. Plain scares me to be inside next to the wheel.

I did repair many rubbed thru wires on the wringing harness that goes back to the Pump and the Starter Relays. Harness is in good repair at this moment.

The inching Valve was leaking a good amount, so I replaced it with one off another machine that is down, this valve does not
leak.
I have looked in the past threads for any info I could glean, I also did a search in this forum for the JLG 534D-9. Read all the threads I could read. I did call JLG, but only got voice mail, and no return call.
I may of over looked the Filters as a issue. I do need to change them.

I did down load the on line service manual, but this does not have a trouble shooting tree for this issue(or i may of missed it in the 368 pages), or any issue really. I have some of the original wiring and Hydraulic diagrams. Which are help full. And all that stated, I am at a loss at what to check next(after replacing the Hydraulic fluid filters).

My premiss, is that if the Solenoids have power with the gear selector in it appropriate place, then the electrical
circuit is working. So it should move. I do not own gauges and test hoses. If I will need these, I may need to pass on this for
my BIL. I am not interested in spending close to $700 for a one off job.

So any suggestions that I can do to help my BIL with his 534 would be greatly appreciated.

Thanks in Advanced.

 

[Robbie Antonson]

Maybe just the new kid/Old dog on the block. 37 views and no insites on this issue. sort of leads me to believe there is a thread I did not find
that has clues.
I went to the web site "https://onlineexpress2.jlg.com/CAGUI/default.aspx". Will do some digging around after I figure out the cross
Labeling of the CAT VS the JLG machines.
Really any help would be appreciated.
Thanks,

 

[Txhayseed]

Your going to need gauges. You can assume its electrical all day. But put a gauge on the test ports and you will know. Power to coils ect only gives you 1/2 the picture. You could be getting power to f&r coils but are the valves moving and is fluid completing its circuit. A pressure gauge will till you right quick. Need to know if parking brakes are getting release pressure. Here again a gauge will tell you. Hard to know what you got going on if you don't have a 360 view of and some baseline stats. A pressure gauge can be had for 15.00 bucks on amazon. Doesn't have to be top of the line but it will help you dial into the problem. If jlg calls you back odds are they are going to want you to check pressures since you checked out basic electrical.

 

[Robbie Antonson]

Thanks TXhayseed;
I got my BIL to pony up for gauges test kit. I got to the point of doing all the electrical and changing the filters. Even ran test wires from the battery to the FR/RR solenoids with no success. Did find some metal in the oil draining out of the Filters. Had the fill strainer removed, so I was able to look in side at the fluid(before and after the filter change), huge difference of flow. So, letting the filter drain over night to cut them open to see the amount and how big the metal may be. Hoping for a control valve stuck, but it may be the main motor.
I have looked for a trouble shooting tree, still have not found one. Did read the pressure test procedures, and will follow
the JLG writing in the Service Manual.