Backhoe my backhoe has lost down-pressure......

hutch4472 · Feb 1, 2007

Thanks in advance for your time.....I have a L35 that I was recently using to install a couple of culverts for a friend. I worked it for about three hours installing the culverts and then fixing up his road. All went fine and the machine worked flawlessly (I love this little machine). I shut her down and left her at his place till I got off work again three days later (which was this morning).

I fired her up and went down to finish digging out one end of a culvert I had covered up fixing the road. Everything was fine till I started to operate the hoe. It has no down pressure at all. Everything else works fine. The loader, transmission, stabilizers, backhoe bucket curl and dump, dipperstick extends and retracts, and the boom will side swing and lift.......but no down pressure AT ALL. It doesnt even make any noise when I push on the stick. It acts as if the tractor wasnt even running. Its as if it was in a float position.

Also the fluid level is good and the fluid and filter were changed about 10 hours ago......I cannot see any fluid leaks anyplace......ANY SUGGESTIONS would be helpful......Thanks again, I always enjoy reading the posts here, you are great group of people.......Hutch

Volfandt · Feb 1, 2007

When troubleshooting it's always best to start at the easiest spot then work towards the hardest.
With this said, the easiest would be to check and make sure that the transport pin is removed

(don't ask, btdt

)

How are the temps out your way? Condensation could have made it's way into the BH spool valve and either froze or corroded that one control.
I'm not familure with your model so perhaps someone else will chime in.

Good luck

AntrimMan · Feb 1, 2007

Perhaps the spool likage for that action has become disconnected (dropped a nut).
Look inside while you move the stick. Use a bright flashlight through the top or remove the front cover panel.
Martin

hutch4472 · Feb 1, 2007

Yes the pin is removed.....but haha, you made me think for a minute there.....the low temps have been down around mid to low 30's for this whole month basically so mosture may be a possibility. The stick is connected to the valve pin still, I have the cover off the valve to confirm that......I am still stumped and bummed out.....thanks for the replies though.....Hutch

bigjohnkub · Feb 1, 2007

On the bottom and top of the valve slice their is another relief valve. It is for overpressure on the clyinder. It is located on the port side, between spool and ports or hose connections. I have seen this several times. the valve part
# is 75595-63200 and is about$250.00. So.... check the cylinder first!

hutch4472 · Feb 1, 2007

bigjohnkub said:
On the bottom and top of the valve slice their is another relief valve. It is for overpressure on the clyinder. It is located on the port side, between spool and ports or hose connections. I have seen this several times. the valve part
# is 75595-63200 and is about$250.00. So.... check the cylinder first!

Hey thanks for the knowledge bigjohn. I will look up that part number in my book to see exactly what your talking about. Basically your saying they fail and need to be replaced, not any way to clean and repair? Also by checking the cylinder you mean just a visual inspection for bent, damaged parts? And how in the heck do you get in there to look at it? I was trying to see if I could get it out of that boom and it looks like a real pain to get at.

Part of my problem (besides lack of knowledge in hydraulic systems) is I am using the tractor to build myself a nice work shop to work on my tractor. All my tools are currently CRAMMED in our 2-car garage (which greatly pleases my wife) awating shop completion, making it difficult to find anything I need.

hutch4472 · Feb 2, 2007

bigjohnkub said:
On the bottom and top of the valve slice their is another relief valve. It is for overpressure on the clyinder. It is located on the port side, between spool and ports or hose connections. I have seen this several times. the valve part
# is 75595-63200 and is about$250.00. So.... check the cylinder first!

You nailed that one Big John, I switched the upper and lower relief valves and then had down pressure and no up on the boom. And I'm out another $250.00 just like you said.........Thanks for the help. Hutch