Loader FEL drops under load

   / FEL drops under load #1  

Buggs67

Veteran Member
Joined
Apr 10, 2014
Messages
1,460
Location
Perry Cty, Pennsylvania
Tractor
Kioti 2014 CK2510 TLB
I had a problem surface yesterday.

I was lifting a quad with my FEL. It's under the rated weight and I've done it before with no problem. I lifted the quad and went to release the joystick and the load immediately started to sink to the ground. I was only at half throttle so I raised the RPM and tried again and again the load slowly sunk to the ground. The only way to keep the load up was to hold the joystick in lift position.

I finished loading the quad on the trailer and since I've read about air in the lines and cylinders I tried cycling the lift and curl function 3-4 times and then did it with bucket loads of gravel. It's better but if I lift a bucket of gravel to head height it slowly sinks (real slowly).

The tractor is only 1.5 years old and has 190 hrs on it. I changed the hydraulic fluid at 50 hrs and have done nothing since then except disconnect and move the lines slightly at the quick disconnects. I'm not seeing any leaks.

I don't think my machine has a quick dump function.

My first guess was the control valve as the bucket seems to sometimes get floppy.

Also I've noticed that the backhoe seems to "leak down" where it didn't used to

Thanks for the help. I'm 15 miles from the dealer and if it's a defect covered under warranty I'd have to hire someone to transport it or pay them to pick it up.
 
   / FEL drops under load #2  
FEL dropping is in the valve.

BH could be valve or cylinder seals, since it is extending while lowering.

Floppy curl could be due to air with lack of a regen function on the valve.

All could be caused by air getting into the system if you have a hole or crack in the suction hose. To rule that out and isolate the FEL valve do the following:

Put a load in the loader sufficient to make it drop. Raise the load ~2' or so and with some blocking and a floor jack, take pressure off the loader. Unhook the hydraulic hose QD's and lower the jack. If the load continues to fall, you have an air problem. IF it does not, its a valve problem.

Now use the floor jack to take pressure off again and re-attach the hoses
 
   / FEL drops under load #3  
Could air be sucked in because the hydraulic fluid is low?
 
   / FEL drops under load #4  
Could air be sucked in because the hydraulic fluid is low?

Only if the system isn't airtight. At which point you have a bigger issue of hydro fluid going out. There is either air in the system (air compresses, thus smaller volume, load drops, fluid doesn't compress), or a leak of some type somewhere, likely the joystick. If the volume is so low it creates a vacuum to pull air in, he would have noticed it in the HST performance, or lack thereof, before now.
 
   / FEL drops under load
  • Thread Starter
#6  
FEL dropping is in the valve.

BH could be valve or cylinder seals, since it is extending while lowering.

Floppy curl could be due to air with lack of a regen function on the valve.

All could be caused by air getting into the system if you have a hole or crack in the suction hose. To rule that out and isolate the FEL valve do the following:

Put a load in the loader sufficient to make it drop. Raise the load ~2' or so and with some blocking and a floor jack, take pressure off the loader. Unhook the hydraulic hose QD's and lower the jack. If the load continues to fall, you have an air problem. IF it does not, its a valve problem.

Now use the floor jack to take pressure off again and re-attach the hoses

This is good thinking. I'll do this and get back to you.
 
   / FEL drops under load #7  
Don't overlook the tractor main hyd relief valve, might be stuck open a hair.
 
   / FEL drops under load #8  
Not the main relief. That would cause a.lack of power, but not a dropping loader. The valve isolates the rest of the system
 
   / FEL drops under load #9  
Your right, I don't what I was thinking.
 
 
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