I get one thing fixed with Dan's help then find another problem. Now pulling back the joystick to raise the FEL causes it to drop unless it's pulled back quickly. I don't see how this is relevant but I did add a WR Long C-Flow kit in order to use my new Lane Shark front end mower. Lane Shark works as it should but after using it for a few hours the problem started with the FEL arms dropping before raising. How can this happen?
LA 525 drops before lifting
- Thread starter AllenBC
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TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
The obvious suspect is a bad load check in the loader valve.
I cant see any relation to the C flow plumbing. Do you have the prpblem when the Lane Shark is not on the loader?
Dan
i wonder if it's possible if the lane shark motor uses more fluid flow than the tractor/pump can handle?
Standard L series tractors aren't really designed to run a constant flow hydraulic motor--which is what the reps told us way back in, like, 2018. Maybe things have changed.
Standard L series tractors aren't really designed to run a constant flow hydraulic motor--which is what the reps told us way back in, like, 2018. Maybe things have changed.
TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
After thinking about this some more I am wondering if the back pressure in the neutral circuit created by the LS motor when its running is somehow presenting a false signal to the load check valve on the loader boom spool. Does the problem go away if you shut the LS motor off?
Dan
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I disconnected the hoses to the Lane Shark as well as the C-return hose to the T after the 3rd function valve: the problem remains even with absolutely no connection to the Lane Shark. (Note: this loader problem did not exist when I first operated the Lane Shark - that argues against an install problem.)
I could re-route the power beyond hose that's connected to the WR Long 3rd function valve to the return at the junction low on the right side like I did at Dan's suggestion when diagnosing the FEL raise/lower function. That would take 3rd function entirely out of service; I don't see how that could change things, but I don't see lots of things.
Here's the terrible thing I have to confess. When trying to solve the orginal loader problem and before I got wise counsel from TheOldHokey, the loader valve was on and off the tractor several times with spools being removed, inspected and reinstalled. All inspections, including one by a dedicated hydraulics shop, reported the valve OK. But (there's always one), there is a small leak letting fluid drop from the front of the valve from an unknown-to-me point on the valve.
I could re-route the power beyond hose that's connected to the WR Long 3rd function valve to the return at the junction low on the right side like I did at Dan's suggestion when diagnosing the FEL raise/lower function. That would take 3rd function entirely out of service; I don't see how that could change things, but I don't see lots of things.
Here's the terrible thing I have to confess. When trying to solve the orginal loader problem and before I got wise counsel from TheOldHokey, the loader valve was on and off the tractor several times with spools being removed, inspected and reinstalled. All inspections, including one by a dedicated hydraulics shop, reported the valve OK. But (there's always one), there is a small leak letting fluid drop from the front of the valve from an unknown-to-me point on the valve.
TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Given that history I would suspect the load check on the boom spool is no longer operating correctly. Should be an easy fix.
Dan
I understand the boom spool isn't working correctly, and I'm happy you say it's an easy fix? Is it to pop in a new spool valve? That would be easy, but not happy!
Soon I have to make 4 trips to a local farm with a full dump trailer to dispose of horse poop mixed with stable bedding - real recycling! Each trip will take 15-20 bucket loads of poop/bedding into the trailer. Reach and height of the LA525 bucket is marginal for this, so having the bucket arms out of control will not be helpful.
On the Lane Shark and heated hydraulic fluid, should I put a temp gauge in the PB circuit and stop when it's too high? How high is too high? Is it better to use genuine Kubota fluid when the system is stressed?
Soon I have to make 4 trips to a local farm with a full dump trailer to dispose of horse poop mixed with stable bedding - real recycling! Each trip will take 15-20 bucket loads of poop/bedding into the trailer. Reach and height of the LA525 bucket is marginal for this, so having the bucket arms out of control will not be helpful.
On the Lane Shark and heated hydraulic fluid, should I put a temp gauge in the PB circuit and stop when it's too high? How high is too high? Is it better to use genuine Kubota fluid when the system is stressed?
The C- Flow kit does provide for a constant flow, but I do worry about overheating. The Lane Shark works well for my application, cutting back brush from roads and pathways. I wish it did brush like a hair clipper does hair, but it takes repeated passed to do the job. OTOH, it way faster than any other method I can have available. Highway department tractors are stronger and faster, but not available to me.
Allen
TheOldHokie
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Kerp it simple and one thing at a time.
The symptoms indicate a malfunctioning load check valve on the boom spool. Its a simple spring and poppet valve that can be accessed by removing the hex plug on the top of the loader valve body. Take the load check apart, verify all the pieced are there and in the correct order, check for any junk inside tje opening that may be jamming it, and put it back together. About 15=30 minutes if you dont lose anything.
Dan
That makes sense and I found a drawing of the parts that are supposed to be in the check valve. Will try tomorrow.
Well that "tomorrow" came with COVID so I have been out of order for a few weeks. I finally looked into the check valve and it wasn't there. On removing the cap, there was just a hole. That didn't seem right so I opened the check valve cover for the bucket and there was one there.
So it seems that the 2 "experts" who had worked on the loader valve off the tractor did not reassemble it completely. If that isn't bad enough, Kubota no longer sell that check valve - looking it up finds a substitute which is the complete loader valve for $1100. Yeah, I am going back to the experts, but without a great deal of confidence.
I did find the check valve kit on Ebay for $90 and, unless you tell me to do something else, I will order it. Picture on Ebay shows it in an original Kubota part bag with the correct number YW368-93100 printed on the bag. The bag looks dirty so it's clearly new-old-stock, but if everything is in there it should be good. With most of the bag covered by the part number, name & UPC, only the cap and spring show in the picture.
It seems these parts are likely generic but I have no idea about how to find the generic equivalent.
I forgot to say that Dan correctly diagnosed the problem being the check valve on the boom side of the loader valve. Once more: Thank you Dan!
TheOldHokie
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You are more than welcome. I would snatch that NOS part up toot sweet. You might also ask the experts where your missing parts are. A good hydraulic shop can probably source something that will work but you dont seem to have one in your neighborhood
Dan
Now Ebay says "Page cannot be found" - merde and scheiss and all that.You are more than welcome. I would snatch that NOS part up toot sweet. You might also ask the experts where your missing parts are. A good hydraulic shop can probably source something that will work but you dont seem to have one in your neighborhood
Dan
Dan, is there harm in using the loader without the check valve? I mean other than dropping something that isn't meant to be dropped. I think I can manage the bad behavior loading the manure that really, really needs to go to my farmer friend - our poo pit is much overloaded!
TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
No harm to the loader valve as far as I know. The load check is just a check valve that holds the work port closed until pump side pressure rises to match the cylinder pressure. Without it there is an initial pressure (and load) drop as the port is opened and pump pressure lags. Many loader valves from the 50's and 60's did not have that feature but its almost universal these days. Without it you get jerky control behavior edpecially when the bucket is loaded so do be careful.
Dan
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I will be careful. I think I can manage it even if the cycle time from poo pit to dump trailer is longer for each bucket load. Thanks for your advice.
Still looking for a replacement check valve. Early this morning thought I had one, Bane-Welker web site said it was in stock and took my order. But when I called after they opened to confirm availability, it was: oops website made an errror! So back hunting.
According to Messick's web site, that spool valve is used on 160 Kubota models. But I would have to search salvage yards model by model but component parts are not listed by salvage companies. Crazy cross-eyed would happen before finding a salvage source. Even if I did, a salvage yard will likely not sell just a part from a loader spool valve.
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TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
I dont understand why this part is not available. They are still selling this loader. It might be worth calling Messicks and talking to someone in parts.
Dan
TheOldHokie
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L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
On a hunch I went to Messicks parts and looked up the LA526. According to them the load check for that loader is $135. Part number is YS020-93100 and again according to them fits 35 other models including - you guessed it - the LA525.
Dan
Temporarily, why not put the check valve from the bucket in the boom section? Bucket jump should be less obnoxious.
For $100, couldn't you make a poppet? Find a bolt the right diameter, cut a plug the right length and drill it the size of the pin. If you have a welder, make a pin out of a nail or screw shank and plug weld it in. No welder, thread the plug and screw a section of screw in it. Chamfer the hole and rivet the end, and/or lock-tite it. Then find a light spring, shouldn't be too critical.
For $100, couldn't you make a poppet? Find a bolt the right diameter, cut a plug the right length and drill it the size of the pin. If you have a welder, make a pin out of a nail or screw shank and plug weld it in. No welder, thread the plug and screw a section of screw in it. Chamfer the hole and rivet the end, and/or lock-tite it. Then find a light spring, shouldn't be too critical.