# Kubota L3250 LA 650 Loader Hydraulic problem



## DallasT (6 mo ago)

I recently rebuilt all four Hydraulic cylinders. No external leaks in cylinders or actuator valves. Problem is the bucket will start to roll down after a few seconds when the handle is released. I can hold the handle very slightly in the roll back position and it will stay stable. The bucket will roll up no problem. Any suggestions? Arbitrarily replacing the control valve repair kits can be rather expensive. I would appreciate any input. Thanks


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## FredM (Nov 18, 2015)

If you don't hold the crowd (rollback) lever, does the bucket go to the full dump position or only sinks a little??.

Are your controls 4 way action?, if there is a rubber dust boot over the control valve, lift this and check that two set screws are tight, if not tight, there wont be full control of the spool valve.

If you are happy with your resealing job on the cylinders, then there may be a weak/broken return spring on the crowd spool valve and this is not making the spool return to neutral position and allowing cylinder fluid to leak back to the reservoir.

Prior to resealing the cylinder rams, if you had no leakdown with the bucket, then the sealing kits in one or both crowd rams are leaking.

And mostly the "O" rings at each end of the spool valves are replaced, 2 to each spool, the "O" rings are there to prevent hydraulic oil from leaking out of the control valve and that is all they do.


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## DallasT (6 mo ago)

FredM Thank you for your reply. Yes the bucket will slowly go to the full dump position when the crowd is in the neutral
position. If it means anything when idled up it takes it a little longer to start to dump. Controls are two way. Up/down dump/rollback. There was no rubber dust boot. Attached is a copy of the parts list. I did replace the spool seal kit D because it was leaking but it had no effect. I think it may have started leaking after we dropped the loader to replace the clutch assembly. I'm not so sure the hoses weren't initially incorrectly connected. Prior to this there was no leak. I don't think the bucket cylinders are leaking internally. Is there a way to test them? i suspect a weak spring and possibly leaking o rings like you said. I'll remove the spool to see if I can see any apparent damage or wear. Does this require special o rings or will any properly sized o ring work? I hate giving $5 or $6 for an o ring and pay $10 shipping. I know I'm going off on a tangent but Lord knows I've spent enough on this one in the last 4 weeks. The tractor is a 1990 model I purchased in 1995. From then until the current job we started 4 weeks ago One bucket cylinder had a small leak and one of the lift cylinders had a substantial leak. I replaced the clutch and of course over the years I have replaced several hydraulic hoses and the 4wd shifting fork I broke out of ignorance when I first got the tractor. Other than a couple sets of tires and a few batteries that's is about it. I have a Landscape and Tractor Service business I started in 1995. I've had several tractors over the years but this old girl is the only one I kept the entire time. No telling how many thousands of hours on it. There was almost 8000 hours when the tack cable broke around 2005. The tractor was in excellent condition other than a few scratches small dents and ran like a top. I'm a firm believer in PMCS I said all that to say this. A new operator and 3 weeks of clearing land of sweetgum saplings and I have replaced a clutch assembly, had to reinforce the bucket (already had a grader blade welded to the front and 3/8 flat metal on the bottom and sides of the bucket). I thought it was bullet proof lol. Repaired all 4 blown hydraulic cylinders Battery jarred loose hit the fan blade, a limb through a radiator hose a hydraulic line ruptured, 3 point hitch bent and broken, lost scarifiers off the box blade, the front axel differential totally destroyed both pinions and both drive gears almost every tooth broke. The shaft collars that are supposed to strip prior to sustaining axel damage both looked brand new go figure. Finally two hours after replacing the front differential the left front wheel broke completely off the axel. Almost forgot lost key and ruined ignition switch hanging by the wires. the entire time I was running a 72 inch grapple with a 7 foot box blade on an RK 37. I did have a limb get in the fan and radiator caused a slight leak that stop leak fixed right up. A 47 Kubota backhoe running at the same time not so much as a scratch. Anyway about $4000 later shared between Messicks and the local Kubota dealer (and we do our own repairs) I'm getting a rental and looking for another operator to finish this job. Ever see one of those people that could screw up a ball bearing? Sorry just had to vent.


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## FredM (Nov 18, 2015)

I don't blame you for venting, I reckon I would have balled the bloke right out after the damage he caused.

And sorry, it has been about 20 years since I have had to rebuild those spool valve banks, I forgot about the "O" rings between the valve bodies, the "O" rings will be metric and some may be specials, do you have a bearing shop near you, they may sell "O" rings, our bearing shops here sell the lot, bearings, vee belts and "O" rings, just to name a few of the products that they carry.

Seeing that the tractor is that old, then maybe the crowd/dump spool is scored, and if badly, then the oil will bypass and cause your problem, should you pull both spools, don't swap them to the opposite valve bodies, the spools are matched with their respective valve body at manufacture.


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## DallasT (6 mo ago)

FredM said:


> I don't blame you for venting, I reckon I would have balled the bloke right out after the damage he caused.
> 
> And sorry, it has been about 20 years since I have had to rebuild those spool valve banks, I forgot about the "O" rings between the valve bodies, the "O" rings will be metric and some may be specials, do you have a bearing shop near you, they may sell "O" rings, our bearing shops here sell the lot, bearings, vee belts and "O" rings, just to name a few of the products that they carry.
> 
> Seeing that the tractor is that old, then maybe the crowd/dump spool is scored, and if badly, then the oil will bypass and cause your problem, should you pull both spools, don't swap them to the opposite valve bodies, the spools are matched with their respective valve body at manufacture.


Thank you sir for your input. I'm sure I will be able to find an o ring of suitable size. Famous last words before spending $6.00 on an o ring and $10.00 shipping LOL. There's really not much I can do until I replace the front wheel gear assembly and attach to the axel. the tractor is still on an equipment trailer. Its easier for me to work on it there. it was a trip getting it on the trailer with only three wheels. We are using the bucket as a crutch while we have the front axel scotched up on blocks and stands. thank you for warning me about switching the spools. I will keep you informed on my findings.


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