New Holland 1920 hydraulic problem

[davidkanoy]

I have a Ford/New Holland 1920 manufactured in 1992 that has developed a strange hydraulic issue. The tractor has a NH 7108 Loader with a WR Long model HJ2 4-1 bucket. I currently have a bush hog brand bush hog on the 3 point hitch. So here's the issue: Unless I have the 3 point hitch in the full up position I have extremely slow loader operation. With the tractor at normal idle and I raise the 3 point hitch the engine slows down 100-150 RPM and the hyd pump arrears to be in a strain. With the 3 point hitch full up, the loader is very fast up and down and curl. With the 3 point hitch in any position other than full up the loader is very slow. The 4-1 bucket in almost non functional in either position of the 3 point hitch.
Here's what I've done so far:
1)Changed the hyd fluid & filter and found brown flakes of a material that appeared to be paint chips or maybe brake shoe material in the top of the filter.
2) Installed a Harbor Freight 5000 PSI gauge in series with the input of the loader spool control and another 5000 PSI gauge in the "A" (open) port of the WR Long 2 position 4-1 bucket Energy valve.

With the 3 point hitch in any position other than full up, I have almost no pressure on the loader control gauge and as stated above the loader is very slow. With the 3 point hitch in the full up, the loader gauge reads 2550 PSI and the loader operates very fast & curls fast. With the 3 point hitch in the full up position the 4-1 bucket port "A" gauge reads 2550 PSI in open, close or center and will not open or close the bucket at all. With the 3 point hitch in the down (or anything but full up) the 4-1 bucket will open & close very slow and has no power.

The on-line New Holland parts breakdown of the hydraulic piping shows a Manifold Diverter, Control Valve Assembly with an adjusting screw. I tried moving the adjusting screw to the other (counterclockwise) position but I did not see any change. This Diverter is making a high pressure fluid rushing sound (when I operate the loader with the 3 point hitch in the full up position)
that I don't remember before this problem started.

I also tried changing the 3 point hitch speed adjusting knob (Turtle/Rabbit), but that had no effect.

I think the hyd pump is OK because I can develop 2600 PSI.

As I stated above, I found those flakes of material in the filter, might a relief valve be stuck open?

ANY thoughts, opinions, suggestions or prayers would be greatly appreciated.

Thanks in advance,

David

 

[Spicer]

It appears that your HPL valve cannot close.

Mike

 

[Spicer]

David, I’m thinking that your HPL valve had a preexisting adjustment problem. It appears that your FEL valve only works when it has back pressure.

This would indicate to me that the diverter valve is not in the 11 o’clock position, the hyd. Power beyond and IN are reversed or your hyd. couplers are not seated.

If you do not have a manual. These hookups should be the same.
http://www.woodsequipment.com/uploadedFiles/Products/Manuals/1000416.pdf


Mike

 

[davidkanoy]

Mike,

Thanks for the input and the PDF.

The operator's manual for the 1920 shows the "control screw" on the diverter valve in the one o'clock position for 3 point linkage operation and eleven o'clock position for auxiliary equipment operation.

The directions in the Long's PDF state to "carefully turn the control screw counter-clockwise 1/4 turn to the 11 o'clock position.

So I will recheck the control screw position again tomorrow. In one position the loader will not work at all, even with the 3 point hitch all the way up.

I fairly sure I have the control screw all the way in the other position, NOT 1/4 TURN as the Long's PDF states.

I tried to locate the HPL valve. I printed off the "1920 4 cyl compact tractor 20 series (1/87-4/02) 05D01 Control Valve, Quadrant & Linkage w/draft control - 1920" exploded diagram and looked that tractor over but can not find the valve. It appears it is located behind a cover on the right hand side of the tractor (facing forward in the seat) but I can not find that cover.

Is it necessary to remove the right rear tire and some sheet metal to get to this area?

Thanks in advance,

David

 

[davidkanoy]

Mike,

On my tractor the Hew Holland 7108 loader is "hard plumbed" to the diverter, no quick connect couplers to install wrong or part-way.

Thanks,

David

 

[J_J]

Is your 4 in 1 bucket controlled by a diverter valve or a 3ed function valve.

Check your solenoid spools for movement.

If you have any QD's check them.

In an open center hyd system, all valves in neutral hyd gages should read no or very little pressure.

Activate each valve and determine if the valve is acting normally.

 

[davidkanoy]

J_J

Thanks for your reply.

The Longs 4-1 bucket is controlled by a separate valve, an Energy Manufacturing model E20038, basically a log splitter valve with a center neutral position. The Energy valve is also "Hard-plumbed" with no quick connects.

The only quick connects this tractor has are the 4 that go to the loader near the bucket itself (up/down & curl/dump) and the loader has never been off the tractor or the quick connects ever used in the 16 years I have had the tractor.

It appears that the "out" of the loader spool valve is plumbed to the "in" of the 4-1 Energy valve and "out" of the Energy valve goes to the diverter valve with the control screw adjustment.

I am going to triple check the position of the control screw on the diverter valve. I printed off the exploded diagram of the diverter valve and I am going to make sure all the parts are present in the relief assembly of the diverter valve. I did take the relief plug, spring, washers, etc. out AFTER I started having the problem to check for trash as I has found trash in the top of the filter when I last changed it (after I started having this issue).

I think I saw some water in the fluid when I changed it. I did not use the tractor much this past winter and maybe I have a rusted, stuck or contaminated valve, diverter, spool or HPL.

I have disassembled both the Energy spool valve and the loader spool valve and found everything clean, free and with no leaks, before & after.

Still trying to locate the HPL valve.

Thanks,

David

 

[Spicer]

There is nothing wrong with the HPL it’s just out of adjustment. We will deal with that later.

The diverter valve needs to be in the 11 o’clock position.

Your hydraulic problems lye solely on the components attached to your diverter block.

I believe there is a problem in your FEL valve. Since your FEL valve is the first component attached to your pressure port.

Mike

 

[Spicer]

Just a reminder; you should limit the use of your FEL hydraulics in its current state. The hydraulic pump was not designed to run at maximum pressure continuously.

Mike

 

[Spicer]

David, You need to follow J.J.’s individual spool pressure test. I will add that the pressure gauge should be placed on the “P” or pressure line before the FEL valve, the diverter valve in the 11 o’clock position and the TPH lowered.

Mike.