FEL pressure measurement locations

[Ben755]

I've posted before about my FEL (Koyker 155) had stopped lifting. It now will raise slowly, but not with a load. I replaced the old FEL control valve with a new
one to no avail. I'm guessing that i have a pressure loss problem
somewhere in the system. What is the best procedure and locations to take pressure readings to isolate the problem. Would pressure reading at the input hose
to the FEL joystick controller tell if the FEL is getting adequate flow pressure from the pump (deadheading or with tee fitting) ? - Also, readings at the lift pressure
end of the lift cylinders ? Since the 3-point lift and FEL bucket dump and curl work fine, would this eliminate a pump problem ?

 

[normde2001]

Yes. Most setups are such that you can swap lift hose with curl hose. If problem stays with lift, bad lift cylinder.

 

[LD1]

I'd start at the work ports of the valve.

Unhook loader hoses, put gauge in work port. Start tractor and actuate valve. Observe pressure reading

 

[Ben755]

I swapped the lift and curl cables and the loader lifts fine with load. I guess this definitely points to the cylinders as the problem.
Strange that there was no leakage or flow by in the cylinders. Thanks for the help.

 

[Ben755]

Wow, I'm thinking wrong here.....the swap tells that the cylinders are good and the pressure in the lift line is weak.

 

[winston1]

Wow, I'm thinking wrong here.....the swap tells that the cylinders are good and the pressure in the lift line is weak.

How did the curl function work with hoses swapped? Are you doing these tests with no load? Doesn't take much to operate curl function with no load.

 

[Ben755]

I didn't check the curl function after the cable swap but thinking later that i should have - just assumed that it would fail. The swap test also vindicates the cabling link from the valve and the lift cylinders.
It appears that it almost has to be the control valve. I have the old valve back on now, but I experienced the same lift failure with the new one - surely, both valves can't have the exact same problem.
The loader spec has a 2200 psi for max lift and the new valve came with the relief set at 2000 psi. I didn't think that this was part of the problem.
The fact that the loader lift worked so well after the cable swap also leads me to believe that the flow from the pump to the valve is also good. I'm at a dead end right now and don't know what else to do.

 

[winston1]

Hard for me to believe you changed out a valve with bad lift function and replaced it with a valve with bad lift function.

Do you have quick disconnects?

Can you make the relief valve go off by moving cylinders to end and continuing to hold handle? You should be able too. Curl and lift.

 

[Ben755]

I replaced the quick connects with threaded couplings due to leakage. Are you referring to the spool cylinders in the control valve and holding the controller stick at full lift and tilt ?
Right now, i have the cables swapped again to check the curl function. The bucket curl function failed. I'm going to put the new valve back on and adjust the relief valve to 2200 psi
when I can get pressure gauge.

 

[normde2001]

Yep, really odd. Everything points to bad control valve, which you already swapped. I guess one would have to be there. Where, exactly did you make the connection swap? Points to hose obstruction out of lift side of control valve, but before lift cylinder.

 

[California]

This shows what adapters you might use to mount a gauge:

For diagnosis, I put on a pressure gauge where the lower hose connects to the OEM divider block.

'Before' photo:
http://www.tractorbynet.com/forums/...oader-plumbing-p1650635rym240dividerblock-jpg

'After' photo:
http://www.tractorbynet.com/forums/...s-series-loader-p1360422rhydgaugefittings-jpg

I intended that to be temporary but its still there. I should have mounted it at the other end of that hose, where it enters the loader control valve. That location would be easier to see while driving around.

 

[LD1]

So it sounds like you have a cable controlled valve.

You have ruled out cylinders and hoses.

You swapped cables and the curl cables work fine on the loader lift.

So we know by that test that the loader lift spool is good.
Before swap, the curl worked fine, so we know that spool is fine as is the curl cables.

At this point, I think all things are possible to lift cable.

 

[newbury]

I swapped the lift and curl cables and the loader lifts fine with load. I guess this definitely points to the cylinders as the problem.
Strange that there was no leakage or flow by in the cylinders. Thanks for the help.

How much "load"? 500lbs?

This shows what adapters you might use to mount a gauge:

For diagnosis, I put on a pressure gauge where the lower hose connects to the OEM divider block.

'Before' photo:
http://www.tractorbynet.com/forums/...oader-plumbing-p1650635rym240dividerblock-jpg

'After' photo:
http://www.tractorbynet.com/forums/...s-series-loader-p1360422rhydgaugefittings-jpg

I intended that to be temporary but its still there. I should have mounted it at the other end of that hose, where it enters the loader control valve. That location would be easier to see while driving around.

Good pics

 

[California]

I replaced my 30 year old loader valve when it dribbled on my shoe while lifting this 650 lb tank. (Photo) I had noticed minor seepage before but this is what convinced me it was time to make repairs.

Relevant to Ben's problem: I found chunks of (presumed) hydraulic hose lining where one of the loader hoses connected to the control valve. It wasn't responsible for the dribble, that was caused by sloppy clearances in the valve, but debris like this might block pressure sent to the loader.

It might be a good idea to blow out the lines if you suspect there might be debris in there. And put the discharge end into a bucket so you can see if anything came out.

 

[Ben755]

The cabling that runs from the lift port on the control valve to the loader cylinder lift ports (both cylinders) was removed and connected to the bucket curl port and the loader raised quickly
with heavy load. That test should say that the cabling is not the problem, and low pressure from the lift port on the control valve is suspect. I put the new control valve back on and it will
raise the loader slowly with load when engine is revved up a bit, but nothing like it raised in the swap test.

 

[Ben755]

So it sounds like you have a cable controlled valve.

You have ruled out cylinders and hoses.

You swapped cables and the curl cables work fine on the loader lift.

So we know by that test that the loader lift spool is good.
Before swap, the curl worked fine, so we know that spool is fine as is the curl cables.

At this point, I think all things are possible to lift cable


No, the lift cables worked fine when connected to the control valve curl function port. Moving the joystick laterally to the left lifted the loader.
The curl cables were connected to the valve lift port and the curl function failed.

 

[LD1]

The cabling that runs from the lift port on the control valve to the loader cylinder lift ports (both cylinders) was removed and connected to the bucket curl port and the loader raised quickly
with heavy load. That test should say that the cabling is not the problem, and low pressure from the lift port on the control valve is suspect. I put the new control valve back on and it will
raise the loader slowly with load when engine is revved up a bit, but nothing like it raised in the swap test.

You are confusing "cabling" with hydraulic hoses it sounds like. Probably why everyone (myself included) is confused.

If you swapped hoses, and the lift works fine, then the issue points to the valve or linkage that controls the valve. Which can STILL be a cable controlled valve. Dont know that model so I dont know there

 

[LD1]

So it sounds like you have a cable controlled valve.

You have ruled out cylinders and hoses.

You swapped cables and the curl cables work fine on the loader lift.

So we know by that test that the loader lift spool is good.
Before swap, the curl worked fine, so we know that spool is fine as is the curl cables.

At this point, I think all things are possible to lift cable


No, the lift cables worked fine when connected to the control valve curl function port. Moving the joystick laterally to the left lifted the loader.
The curl cables were connected to the valve lift port and the curl function failed.

Was typing when you posted this. They are NOT cables. Thus the confusion.

 

[Ben755]

Yes, of course, I should have written hoses instead of cables - it just didn't come to mind that I keep writing cables. Well, I don't know enough about directional control valves to realize that
cabling could be involved. I don't think that is the case with my valve though. I'm using a 2 spool open center single stick valve from Brand Hydraulics - very similar to the valve that came
with the loader.

 

[CalG]

Ben

Have you checked the pressure relief on the valve "similar to the valve that came with the loader".
The adjustment is under cover cap.
Sometimes they are set "very light". Just a usual manufacturing variable.

Remove cover, loosen lock nut, screw the adjuster in three or four turns and see what happens. I had a new "Prince" three spool valve with the pressure relief set to less than 1k psi as supplied.

Talk about poor lifting...;-)

There may be some "issues" with the power beyond and return to tank line installation as well.

You really should draw yourself a picture of how EVERY HOSE AND LINE IS CONNECTED TO THAT VALVE.
It\s easy to get lines crossed.