L3901 Loader Failure
- Thread starter AllenBC
- Start date
TheOldHokie
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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
To me it sounds like the PB outlet is deadheaded by something down stream but the backhoe says otherwise.
i propose the next step is to reroute loader PB straight to tank and test loader functions again. That will tell us if ots the loader valve or not.
Dan
I'm willing but am losing light tonight so it will be tomorrow. I know where the tank hose connects to the backhoe, but not where to connect it directly to the tank. Any advice would be appreciated.
On thinking a bit more, I suppose the place is where the other backhoe hose connects to the body of the tractor, somewhere down below.
Here's a question. I have an adjustable restrictor in the line from the 3rd func valve to the connectors on the front of the tractor for my snowplow. I don't see how that could interfere, but I bring it up because the degree of restriction hasn't been consistent.
On thinking a bit more, I suppose the place is where the other backhoe hose connects to the body of the tractor, somewhere down below.
Here's a question. I have an adjustable restrictor in the line from the 3rd func valve to the connectors on the front of the tractor for my snowplow. I don't see how that could interfere, but I bring it up because the degree of restriction hasn't been consistent.
TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
If the spool in tje 3rd function is in neutral none of that matters.
Its an easy test. The loader PB is hooked to P on the third function and T is connected to the hydraulic outlet block. Diisconnect both those hoses and connect the PB hose to the hydraulic outlet block - lower rigt port in the picture.
Now PB is going straight to tank. Start the tractor and test loader up/ down. Dont curl tje bucket because that will dump oil put the tank hose. You can put it in a bucket to be safe.
If the loader works plumbed like that the valve is fine and there is more detective work to do.
Dan
I wasn't thinking that removing the backhoe leaves the lines to be connected easily - biting head to tail for both the tractor lines and the backhoe whips, something you do when you take the hoe off. I have never taken this backhoe off before, but I know in general how to do it. Might as well go on and get the experience because I am thinking of buying or renting a box blade to fix some gravel paths between horse pastures. I have a backhoe dolly made for my previous tractor's 3-point hoe that should work OK for this one.
I had not seen your last reply when I last replied. Would removing the backhoe and linking hoses work as well?
TheOldHokie
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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Please, keep this as direct as possible. Adding the backhoe simply complicates things snd adds variables.
Use tje hydraulic outlet - its right there and both hoses have JIC swivels. Less than 5 minutes to make the connections.
The impossible happened. Absolutely impossible. Routing PB from the loader spool valve directly to the hydraulic block tank port completely restored the loader boom operation.
This happened despite it not working when connected to the PB circuit that we know is clear because the backhoe operates when PB from the spool valve is connected to the 3rd func valve which leads to the backhoe then to tank.
Dan, I know I don't need to explain all this to you but I want it here for any other readers who haven't followed all the bloody details. But now it's up to you to explain this impossible outcome.
I did not test curl/dump in this configuration because the spool valve to hydraulic block line is open. I can put it in a can to catch the fluid if testing that function is needed.
This happened despite it not working when connected to the PB circuit that we know is clear because the backhoe operates when PB from the spool valve is connected to the 3rd func valve which leads to the backhoe then to tank.
Dan, I know I don't need to explain all this to you but I want it here for any other readers who haven't followed all the bloody details. But now it's up to you to explain this impossible outcome.
I did not test curl/dump in this configuration because the spool valve to hydraulic block line is open. I can put it in a can to catch the fluid if testing that function is needed.
TheOldHokie
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Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Thank goodness. I was beginnimg to think brain rot had finally taken out my last few brain cells.
I cannot tell you what is wrong but I can help you find it. Got a doctors appt this AM and will check back in around 10:00.
Meanwhile you can put the loader PB and tank lines back where they were. We can give it a clean bill of health and I will ponder what next while sitting in the waiting room.
PS> Might want to cancel your replacement valve order
OK, will put lines back. One of my granddaughters comes to visit at 11 today and that takes priority over everything else. I will be back with wrenches mid afternoon. BTW, she just finished her first year at Georgia Tech so she might enjoy hearing about this mess. She's not in ME, but still.
TheOldHokie
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Lifetime Member
Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
After some thought I did come up with a scenario that fits all the symptoms. If one of the spools on the backhoe is not in neutral it would block upstream flow but all of the other backhoe functions would work fine. Give the controls a jiggle especially the stabilizers. Maybe its that simple and we can get lucky....
Dan
Dear Exalted Guru, you did it once again. Just like people say on the forum.
One of the stabilizer levels was stuck partially engaged. When I released it there was an immediate reduction in engine load. AND BOOM WORKS. Thanks so much!!
FWIW, my mobile mechanic not only missed it but his consults with several dealership mechanics with years of experience never brought it up.
Yotekiller
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Equipment
Kubota L2502, LP 60" BB, LP pallet forks, 60" KK Tiller, 55" HSI root grapple
Dan strikes again!! His star shines bright.Well done! I was glued to this post the entire time hoping to learn as well.
FWIW, my mobile mechanic totally missed it and when he consulted with several friends who are dealership mechanics, some with decades of experience, none suggested this as a possibility. Dan's idea to directly test the PB circuit was key.
Of course I should have noticed the cocked stabilizer lever long ago but then I would have missed all this fun.
Dan deserves a special kudo for not dumping on me for confusing open and closed hydraulic systems.
RCW
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BX2360, FEL, MMM, BX2750D snowblower. 1953 Minneapolis Moline ZAU
I've been glued also!
So glad Dan and Allen got it sorted out.
I had noticed in the past the stabilizer lever not always returning to the center position but the stabilizers worked OK so I ignored it. Never again! Should I look into that control system to see if anything needs lube? The tractor lives in its own garage so this didn't happen due to weather exposure.
One suggestion I got that sorta reflects a similar problem. That was to make sure the 3-point hitch wasn't in the full up position - I guess being full up can put that valve out of neutral causing the same problem.
I would have been really depressing to install a new loader spool valve and have the same problem. Thanks Dan for sparing me that.