Losing Hyd Power?

   / Losing Hyd Power? #1  

GaryK

Silver Member
Joined
Apr 12, 2000
Messages
236
Location
NC
Tractor
JD 4100 HST
I have noticed recently that my FEL on my 4100 JD does not seem to have the lifting power it used to have. Its over 1 year old, I think its out of warranty. any thoughts on how to do a quick check without guages and all that?
 
   / Losing Hyd Power? #2  
How's the oil level in the HST sump? Does the 3 point lift still work OK?

DFB
 
   / Losing Hyd Power?
  • Thread Starter
#3  
oil level is OK, no leaks, 3 pt works, just appears that FEL does not have the lifting power it used to have. I'm thinking it has an internal leak and wondering how to check without too much hassle.
 
   / Losing Hyd Power? #4  
Gary:
The little loader on my B7100 has about 800 hours on it. At times the control seems to hang up or not fully operate the bucket. It even gives out a loud squeal the odd time. The control handle is 1/4 way worn through from banging on the lip of the controler mounting frame. The controller probably needs a rebuild but will wait till it almost stops working. Have to put a cutting edge on the bucket first and $$$ are not that easily found.

Egon
 
   / Losing Hyd Power? #5  
Right, internal leakage in the control valve or cylinders.

In the tech manual there is no specific test for the loader just for the overall hydraulic system. Since the fluid level is right and the 3point lift still functions ok that should hopefully rule out any problems with the pump itself or the system relief valve.

The pump intake filter screen might be clogged up and need cleaning. That's the one located at the back of the transmission housing. If there is a low flow measured at the SCV coupler (flow test shows less than 5 gpm) or between the pump and rockshaft housing (no scv) that is the suggested solution

Troubleshooting guide also says to look for loose fittings allowing air to enter the system.

Check all the hose coupler fittings for tightness. Hydraulic line fittings too. There is also a tiny lift circuit orifice installed in the fitting on the end of lift cylinder hose. (green cover) Unscrew the coupler from the hose end to access it.

JMIII previously posted the acceptable leakdown rate for the JD loaders along with test procedures to determine if either the SCV or cylinder is leaking.

Here's the link to those specs <A target="_blank" HREF=http://www.tractorbynet.com/cgi-bin/compact/showthreaded.pl?Cat=&Board=jdown&Number=89453&Search=true&Forum=All_Forums&Words=&Match=Entire%20Phrase&Searchpage=0&Limit=1000&Old=1day&Main=89426>leakdown test</A>

According to 4100 tech manual there are no servicable parts in the DSCV.
"If SCV is worn or not functioning correctly after after cleaning replace entire unit"

Best I can do.

DFB
 
   / Losing Hyd Power?
  • Thread Starter
#6  
Thanks, I will check it out this week. I used the FEL to spread 4 loads of gravel this week and the SVC is acting a little weird, sometimes not to responsive in tipping the bucket. always something..............Might have to clean the SCV, not that many hours on it. I hope its just foreign material, not a replacement.
 
   / Losing Hyd Power? #7  
GaryK Good luck!
 
   / Losing Hyd Power? #8  
Well, it looks like Ziggy is going to have to spend his first night out in those cold, dark, scarey woods alone tonight. Seems I was out back trying to clear a path to what will be a new pasture. The previous owner harvested the big timber about 7 years ago, but didn't stump it. So there are some 3 ft. deep skidder tracks that I was trying to fill in. All of a sudden the FEL wouldn't lift. So I started backing out ...dragging the bucket. Shut him down and climbed off.

After pulling the two cowl covers, I notice a 20 yard trail of precious bodily fluids running up under the tractor. Apparently, a stump that I had pulled, swung up a crushed (and I mean crushed) the filter and took off a 1" line to the filter assembly. I have repaired the line and removed the filter. I will go to the dealer in the morning for a new filter and ten gallons of fluid.

Is there anything special that I need to do to bleed the air out of the lines once the fluid is running again? I read the manual (RTFM) and for break-in they just say to move the FEL stop to stop three times and it will bleed the air.
//bruce
 
   / Losing Hyd Power? #9  
<font color=blue>they just say to move the FEL stop to stop three times and it will bleed the air</font color=blue>

Bruce, I'm not a mechanic, but I think that's about all there is to it. I'd fill'er up, start'er up, move all the controls back and forth to the stops, shut'er down, and check the fluid level to see that it was still full, and go to work.
 
 
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