Front end Loader LA302

[grsabourin]

Hi,

I have a front end loader (LA302) on my B7500. Seems that the valve is leaking. The bucket is not staying up. Is it possible to rebuild this valve? If yes what I need to change.

Thank you

 

[Dave_eng]

Hi,

I have a front end loader (LA302) on my B7500. Seems that the valve is leaking. The bucket is not staying up. Is it possible to rebuild this valve? If yes what I need to change.

Thank you

It is rare for hydraulic valves to leak internally. The moving part called the spool is fitted to the bore in the valve body with such precision seals are not required. In short, rebuilding is not possible as the spools and valve body are a matched set.

Suggest you perform the attached tests on your loader cylinders. It is much more likely an internal seal leak within the cylinder(s) is allowing the drift down.

To confirm it is not the valve you could temporarily swap bucket and lift arm hoses to see if the problem persists.

Dave

 

[grsabourin]

Thanks for this advice and guideline for cylinder testing. I will perform the test and give results details

 

[grsabourin]

It is rare for hydraulic valves to leak internally. The moving part called the spool is fitted to the bore in the valve body with such precision seals are not required. In short, rebuilding is not possible as the spools and valve body are a matched set.

Suggest you perform the attached tests on your loader cylinders. It is much more likely an internal seal leak within the cylinder(s) is allowing the drift down.

To confirm it is not the valve you could temporarily swap bucket and lift arm hoses to see if the problem persists.

Dave

Over the weekend I have performed test proposed by Dave_eng. It is a nice test easy to do. In my case I have removed on side of each cylinder from the loader. In this case it was easy to perform the test having le loader steady on the ground and just the two cylinders extending. The conclusion is clear one cylinder is leaking. For left one, I have oil coming by the port in extending and retracting. This one has to be rebuilt. Is it something feasible by myself or I have absolutely to bring it to hydraulic shop.

Other interesting observation. On my way to put back cylinder pins in place, I have already connected on cylinder (good one) and I was in progress to connect the second one (bad one). I have observed that the cylinder was always slowly extending alone without touching valve lever. Do I need to add other conclusion like defective valve in addition to my defective cylinder?

Thank you for your help

 

[Dave_eng]

Over the weekend I have performed test proposed by Dave_eng. It is a nice test easy to do. In my case I have removed on side of each cylinder from the loader. In this case it was easy to perform the test having le loader steady on the ground and just the two cylinders extending. The conclusion is clear one cylinder is leaking. For left one, I have oil coming by the port in extending and retracting. This one has to be rebuilt. Is it something feasible by myself or I have absolutely to bring it to hydraulic shop.

Other interesting observation. On my way to put back cylinder pins in place, I have already connected on cylinder (good one) and I was in progress to connect the second one (bad one). I have observed that the cylinder was always slowly extending alone without touching valve lever. Do I need to add other conclusion like defective valve in addition to my defective cylinder?

Thank you for your help

It is wise to have cylinders re built by pros. Yes you can do it yourself but to do it properly you need to make special jigs.

I will attach some info for you to read.

Still doubt you have a valve issue. If you do then replacement is needed not repair.,

Dave

 

[kubotafreak]

Seal kit for boom cylinder L or R There are two part numbers so you will want to confirm which fits your cylinders based off the cylinder number stamped in the tube.

Seal kit for bucket cylinder L or R. There are two part numbers so you will want to confirm which fits your cylinders based off the cylinder number stamped in the tube.

 

[Henro]

I got the curl cylinders from my LA402 loader rebuilt by a local shop for $100 each last year. The Kubota seal kits would have cost me around $60 each plus delivery.

No regrets. I figured it would make sense to have a pro do it, especially since I would forget what I learned doing it myself, by the time I again needed to rebuild a cylinder!

The difference in out of pocket cost was worth it to me. Turn around was about a week though.

 

[grsabourin]

Thank youbfor all advices. After looking at some video, I can certainly rebuild it myself but considering time and tooling investment I will leave my favorite hydraulic shop doing it for me

 

[netxtown]

I have same problem on my 203 bucket.

AND... some very excellent vids on how to rebuild were posted a few days back.

Cylinder Reseal/Repair PT1

www.orangetractortalks.com

 

[Blkvoodoo]

Just today I rebuilt all 4 cylinders on my LA352

clean place to work, a good set of picks, some patience and it is entirely doable.
I used a small chain wrench to break all gland nuts loose prior to removing cylinders from loader frame. Just loosen the nut, that’s it while still attached.

Ensure there is no load on any cylinder, have a catch pan and cardboard under the loader frame ( disconnected from tractor). Be aware the cylinder will be full of fluid on rod side when fully retracted.

i ordered the seal kits from Messicks, verified serial number breaks and all went well.
My Ryobi 1/2 impact was able break the nut loose on piston (that surprised me) I did apply blue loctite to the nuts when reinstalling.