Perplexing Hydraulic Problem

[MChalkley]

Todd - <font color=blue>To test flow, does it make sense to run the FEL hose into a bucket for a 1/4 minute and compare that to the flow for a 1/4 minute on the power beyond hose</font color=blue>

That's precisely what I'd do, except I'd probably only let it run 5 seconds. If you don't compare the rear to the front, it's hard to get any meaningful data, so that's a good idea. Make sure you don't run the reservoir dry, though.

 

[jinman]

I think you have a good plan, Todd. I echo what Mark C says about keeping fluid in the reservoir and keeping it clean may also be a challenge. BTW - Can you take a picture of your power beyond connection? I remember seeing pictures of your tractor and trenches. I don't know what I'd see in the picture, but I feel really funny talking to you about something I've never seen plumbed on your tractor. /w3tcompact/icons/crazy.gif If you can't, don't worry about it. We'll just keep at this 'til we figure something out. /w3tcompact/icons/smile.gif

 

[toddwulf]

OK Gentlemen. PG&E (Power Co.) signed off on the underground conduit and sand over job so this weekend I can get my pull lines in and push the dirt back in the trenches. Then final sign off and I've got power to the building site when they actually come in and pull the wires.

So I should be able to start working on further diagnosing the problem the following weekend. I need to start prepping 4 acre's for pasture/corral and for this I need the 3Pt.

 

[jinman]

Okay, Todd. The first thing you will need to do is to remove all the plumbing required for your backhoe (power beyond, quick connects, etc) and restore the tractor to stock configuration. If the 3PH still doesn't work, then get ready to pull the seat and remove your hydraulic lift assembly...or put it in the shop and have them do it. I could be wrong, but I don't think you have any relief valves you can check without doing this. You might be able to get to the flow control valve, but I doubt it. ...and by the way, I'd love for you to prove me wrong about this, but I think your problem is internal to the hyd. assy./w3tcompact/icons/crazy.gif

 

[toddwulf]

OK all you helpful TBN'ers. I've got the tractor home (Got all my trenching signed off and filled back in) and NH got me the manual pretty quickly. I'm going to start with the basic flow tests Saturday along with a study of the Manual tonight. I'll post prelim data tomorrow to post here and hopefully it's an easy fix.

Todd in Placerville

 

[MikePA]

What happened???? Inquiring minds wanna know!! /w3tcompact/icons/smile.gif

 

[toddwulf]

Well, It turned out to be one of those weekends. Since I'm currently building a house (with a garage bay for the tractor) and my current rental garage is stuffed full of our life's belongings, I am forced to wrench on her outdoors. Couple this with the fact that it was the wife's weekend away with the girls and I had the 3 kid's(4-6&8) and on Saturday we got a hell of a storm that blew in, that left Sunday.

What I was able to do in between kid time, was remove the relief check valve in the part I can't name right now because I'm down in Los Angeles on a biz trip so I don't have my manual, to see if there was debris or where there. It looked OK (and just like the manual said it would like) and I reinstalled it and I still have the problem. I didn't run the flow test for various reasons but my gut is telling me that perhaps I ought to first replace the power beyond hose with a new one (Got a local shop that'll make it in a couple hours) and see if it's that simple. Looking at the schematics in the manual, getting into the tranny to check those relief valves is not minor job and I'm not sure I want to tear it apart and while it's outdoors.

The manual also showed how to test the system for pressure so I may go and see about putting together a pressure guage rig with various fittings so I can test in various points along the hyd. system.

Sooooo, hopefully, this weekend I can get a few more steps under the belt because at some point, I'll have to get it to the shop if I can't figure it out. Do you suppose if I get to this point a Hyd. specialist would be better with my manual or would NH be a better place to go?

Talk to you guy's this weekend.

Todd in Placerville

 

[jinman]

<font color=blue>Do you suppose if I get to this point a Hyd. specialist would be better with my manual or would NH be a better place to go? </font color=blue>

I'd go with New Holland. A hydraulic specialist would have to spend the time to learn your system and New Holland should be very familiar with the system and have a ready source of spare parts. ...just my opinion.

 

[toddwulf]

OK Gentlemen, With Manual in hand and a nice sunny weekend to tinker, here's what we've got.

The easiest relief valve to check is the Combi System Relief and Diverter Valve. It appears to be OK after removal and inspection. I did however encounter a small bit of metal debris about the size of a large grain or two of sand when I cleaned it out. I'm beginning to suspect some kind of contamination and blockage in the Relief valve(s) located within the 3 PT. system. Any relief valves that are within the 3 Pt. Assy. will have to be checked by the dealer as I just don't feel comfortable opening her up without a garage to keep out of inclement weather not to mention this would really test my mechanical aptitude.

In my flow tests, I got 15 OZ. of fluid from the power beyond hose and 9 OZ. from one of the FEL hoses. I have to keep in mind that the Power Beyond Hose is twice as thick as one of the FEL hoses. It appeared to be quite easy to stop the flow from the Power Beyond Hose. So I've got flow but no pressure.

In the Troubleshooting section of the manual, I looked for common points between "Implement fails to lift" and "Implement rises to slowly". They are as follows:

1. Bad Saftey Valve
2. Bad Hyd. Pump
3. Oil Leak Past Lift Cycl.
4. Restricted Suction Folter
5. Control Valve Plunger Stuck Open
6. Lowering Valve Spool out of Adjustment.

Non Common Points include:
1. Linkage Adjustment
2. Relief Valve Setting Too Low
3. O Ring Failure at Valve Body to Cover
4. Bad Relief Valve.

With that in mind, I think we can eliminate a Bad Hyd. Pump as the FEL works just fine (Can lift a full bucket of sand/Dirt etc...There is no suction filter in the 1920, only the 2120, eliminating that cause. Control Valve Plunger Stuck open doesn't ring true as I can control the rate of 3Pt. arm descent with the control valve. That leaves 1, 3 and 6. I would also include potential blockage in the Hyd.Control Valve and/or the Flow Cntrl.Valve, both of which are contained within the 3Pt. Housing Assy.

At this point, and after discussing with the NH shop last Thursday, I will bring the tractor down to the shop and let them take it from here. They'll charge me $61/Hr. and are just as stumped on this as we all are so they've taken this as somewhat of a challenge. Perhaps they'll go easy on my checkbook but I need to get it fixed.

Any thoughts at this point?

Todd in Placerville

 

[jinman]

I'm still convinced it's an oil leak due to a busted seal or a stuck relief/safety valve...but I lost all my money on St. Louis in the Superbowl, so I'm too broke to bet./w3tcompact/icons/laugh.gif