# L48 Hydraulic Failure



## DesertDigger

I have an L48 TLB with a little over 1200hrs on it. It has been working fine but the front loader, 3-point hitch, and power steering all quit working. I did notice the front loader seemed to require more rpms to provide the same amount of lift it had been providing about 50hrs or so ago. The fluid is clear and topped off (I check it regularly). I can see the drive shaft to the front hydraulic pumps spinning when I start the engine. Any ideas where to look for the problem? I am new to hydraulic systems and Kubota mechanics.


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## al b

I see this is a old post, could it be a clogged filter? Have you figured it out yet? I have a L48 so I am interested how you make out


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## DesertDigger

I believe I have just discovered the problem. I started my troubleshooting by replacing the two hydraulic filters as well as the transmission filter. I also removed the bottom suction line screen filter and cleaned it thoroughly. This did not change the problem. I then got the tractor over to my backhoe close enough to hook up the backhoe hydraulic lines. The backhoe did not work either but the backhoe swing function did, so that told me pump #3 was operational. After looking at the hydraulic schematics I was able to determine the common point of failure had to be the front hydraulic pump (1&2). I ordered a new one and waited for it to arrive. When I pulled out the old pump I found the internal splines inside the drive shaft connector to the pump had sheared off. When I pulled off the connector from the pump nothing but rust dust came out. The process of the connector splines shearing off also damaged the mating splines on the pump shaft. I have ordered a new connector which should be here by this weekend.


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## al b

That sure looks like it. I had the same thing happen to my L345DT a couple of months ago. That one has a 3/4 round shaft with a key way. The yoke and the key let go and the loader stopped. I put new parts but the loader wouldn't work right It took a while for me to figure out the pump has to be in line or it doesn't pump right. I would tighten the set screw on the yoke and it would put the pump shaft off center. I found out one time when I started the tractor and left the pump mounting bolts loose, the pump had little wobble but the loader worked good then I tighten the pump down and it would not work . Next I contacted Loctite and they suggested I use some thread sealer 242 to take up the .005 the shaft wore out when it spun . I put it together and let it set 24 hours before I tighten the set screw. Started it up and I could not see any wobble. I got it back together and used it for an hour and so far it is OK. Call Loctite customer service and ask them if they have something that will help. I my case they suggested 242 because I wanted ease to take it apart if I had to and I only .005 wear. The wear on your spline I think you would use something else. Ask about something you could use that would come apart if you had to.


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## kubotaL48

I have a L-48 same problem
How did you remove the pump??? Did you take out the radiator?? It looks imposible from underneath the tractor..

[email protected]


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## DesertDigger

Yes, you have to get at the pump from the top. You have to remove the battery and take the plate under the battery out. I have attached a couple of pictures that should give you some idea. Good Luck!


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## kubotaL48

Hi Ya

Thanks for the pix a huge help, I have pump out and boy what a job it was to get the shaft out of the pump, lots of rust, My splines don't look as bad but I didn't totaly lose use 

Thanks a mil
Dan


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## DesertDigger

Dan, Glad I could be of some help. I had a lot of trouble getting the drive shaft disconnected from the pump connector assembly. There isn't a lot of room to get a wrench in there. I hope all goes well with the re-assembly and future use.

Craig


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## kubotaL48

Hi Ya

Just found out that this wasn't my problem that my splines are rusted but when they go they go, they just don't skip per kubota mechanic...... (( He looked at pump and said seems to be ok?? any other advice??? did you upgrade your shaft coupling read a couple of post about them breaking. quoted 700 for up grade parts and 977 for a new pumps. 

Dan


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## DesertDigger

Dan,
Are you talking about the connector that connects the drive shaft to the hydraulic pump? If so, did you see my pictures from the post of 09-19-2012? The second picture shows that connector with its splines worn off. I believe this was my main issue with the pump failing. The part was about $70-$80 new if I remember. I had already ordered a new pump before I found the connector problem so I went ahead and install both.

Craig


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## Worksnowwater

Big thanks to this thread. Saved me buying a new pump and then realizing it was the coupling.


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## Brian15

kubotaL48 said:


> Hi Ya
> 
> Just found out that this wasn't my problem that my splines are rusted but when they go they go, they just don't skip per kubota mechanic...... (( He looked at pump and said seems to be ok?? any other advice??? did you upgrade your shaft coupling read a couple of post about them breaking. quoted 700 for up grade parts and 977 for a new pumps.
> 
> Dan


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## Brian15

Hi. New here. Yes I had the front driveshaft break twice. The fiberglass shims seem to break when the tractor is on uneven ground. I installed the upgraded shaft myself. It has a CV joint which I was told will never break again. It is not a fun job but possible with patience. It's been 3 years trouble free and today my loader, 3 point hitch and power steering all suddenly stopped working at the same time. I had a dealer pickup the tractor this time and they found the coupler splines stripped where it goes into the front pump. See the pictures above from DesertDigger. Part is on order. In the mean time I have to hire someone to plow my driveway. Seems to be a common weak spot on this tractor. GRRRRR


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## Gary Willer

Where can you get the upgrade shaft? My fiberglass shins broke too.


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## Brian15

I ordered it from a Kubota dealer. They didn't treat as a recall but rather a product upgrade. I am sure that way it isn't warranty. The right way to order it is to ask for the upgraded CV driveshaft kit for the front oil pump. Good luck


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## Gary Willer

Gary Willer said:


> Where can you get the upgrade shaft? My fiberglass shins broke too.


Thanks! Dealer says upgrade is $800 and could not tell me what it included. Do you recall what you paid and what was included?


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## Brian15

It was a few years ago but I didn't pay near that much. I thought it was more like $300 to $400 CDN. You get a new shaft with a CV coupler on each end. Everything was in the kit. Read the instructions carefully as the driveshaft has to be put in a certain direction. Not rocket science though so don't be scared. The hardest part was the cramped quarters to work in. Good Luck.


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## Gary Willer

Thanks Brian. At least I know what is in the kit. Dealer could not tell me. I went back with the fiberglass shims. If they break again I may go your route.


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## Gary Willer

Gary Willer said:


> Thanks Brian. At least I know what is in the kit. Dealer could not tell me. I went back with the fiberglass shims. If they break again I may go your route.[/QUOT


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## Gary Willer

Brain any way to could send a photo of the upgraded shaft? I tried to use HMHD plastic to replace the fiberglass shims but I have broken the bolts on the pump flange twice. I may have a relief valve issue .


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## lonmanone

I've had same problem with broken discs( 3 Times) I got a half hour work time each, out of the two successive fixes. I have the new upgrade but it is 5/16 " too long. Now Im figureing out my next move. You would think since it is a double ball joint configuration that it would have some slack at each end... but no.


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## lonmanone

here is a pic of the improved front pump shaft. this picture is missing the flange on one end but it looks exactly like the end that is installed in this picture. $850.00.


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## Bob-L48

lonmanone said:


> here is a pic of the improved front pump shaft. this picture is missing the flange on one end but it looks exactly like the end that is installed in this picture. $850.00.


Do you have a part number my dealer only has a shaft improved kit 32771-9970-2 not the hole shaft replacement thanks


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## Bob-L48

lonmanone said:


> here is a pic of the improved front pump shaft. this picture is missing the flange on one end but it looks exactly like the end that is installed in this picture. $850.00.


do you have a part number for the improved shaft thanks


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## lonmanone

yes the part number is 32771-99702. It is called the improved kit as you described. It includes everything from the crank pulley to the pump Sorry for the delay, I hope you got yours fixed. Now back to my issue with the improved shaft being too long....It appears that the front pump bracket had gotten bent and that shortened the length from the pump shaft to the crank pulley. After installing (and paying for) another improved shaft kit, things are working well


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## Bob-L48

lonmanone said:


> yes the part number is 32771-99702. It is called the improved kit as you described. It includes everything from the crank pulley to the pump Sorry for the delay, I hope you got yours fixed. Now back to my issue with the improved shaft being too long....It appears that the front pump bracket had gotten bent and that shortened the length from the pump shaft to the crank pulley.
> After installing (and paying for) another improved shaft kit, things are working well Thanks for the reply I put the updated parts in the shaft down hill I put 3/8 washer to raise the pump up working so far Thanks


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## Ed Williams

Just curious. That seems like an excessive amount of wear on a splined joint with only 1200 hours. Is any lubrication recommended to address the dry rusty joint. Can you expect a similar failure in the future if the CV joint upgrade is not installed? I was a little surprised at seeing a dry splined joint in that application.


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