hello, has any one had to replace the pump in there HST transmission, if so did you have to split the machine?
Thanks in advance
Thanks in advance
l5030d transmission problems
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rbargeron
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Equipment
L5450, L48, L3250, L345 never enough attachments
May I ask what's going on with your HST that has you wondering about replacing a pump?
To answer your question there's no access to an HST's internals without splitting the tractor.
There are really two pumps in an HST, a small one that keeps the oil circuit full, and the main pump driven by the engine. It's flow goes to the HST motor which turns the transmission either forward or backward at variable speed. Pressures in this circuit can be 5,000psi or more.
If an HST needs its main pump replaced, the matching motor is likely damaged too. If you could describe what its doing we could help better. I've had my L48's HST apart and learned a little about them. Take care, Dick B
To answer your question there's no access to an HST's internals without splitting the tractor.
There are really two pumps in an HST, a small one that keeps the oil circuit full, and the main pump driven by the engine. It's flow goes to the HST motor which turns the transmission either forward or backward at variable speed. Pressures in this circuit can be 5,000psi or more.
If an HST needs its main pump replaced, the matching motor is likely damaged too. If you could describe what its doing we could help better. I've had my L48's HST apart and learned a little about them. Take care, Dick B
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The tractor is loosing power like the trans is slipping, the tractor has trouble well cutting grass on inclines but dose ok on flats. The dealer replaced the pump for the loader and 3point last year. The tractor has been been having trouble since I got it back and it is getting
rbargeron
Well-known member
Lifetime Member
Equipment
L5450, L48, L3250, L345 never enough attachments
Just thought of something - are you mowing in Low, Medium, or High range?
Any chance it was mistakenly left in High? I did that when I first drove an HST ! It was ok except going uphill with a load - then it acted like it was slipping. Medium was the answer.
Any chance it was mistakenly left in High? I did that when I first drove an HST ! It was ok except going uphill with a load - then it acted like it was slipping. Medium was the answer.
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I cut in med, always have, I run between 3.5-4 mph . I pull a 15 foot finish mower, I have never cut more than 2 inches. I have done this for the last 8 years. I have 1740 hours
The tractor has always had a slight hesitation before it starts to go in both medium and high speed for several years. It was kind of jerky. After the dealer's replaced the pump for the loader and three point it gotten much worse. The dealer tried to adjust the pressure on the hydraulics and there was no improvement. I'm getting the impression the hydrostat transmission is better off to change the whole thing then the pumps please let me know if I'm thinking wrong.
rbargeron
Well-known member
Lifetime Member
Equipment
L5450, L48, L3250, L345 never enough attachments
From my distance (MA) nothing is certain - but if you've noticed the HST getting worse over time and the dealer has already tried external adjustments (not much is possible) replacing the HST may be what's needed.
This HST is the next generation after the one in my L48. It's redesigned for the L30 tractor models but the operating principles are the same. They have very high-precision internals and rely on perfectly clean fluid. They usually last a VERY long time without trouble. But the smallest metal fragments can ruin the mirror-finish surfaces on the slippers, swash plate, valve block etc. So when they stop functioning the damage is often extensive and a new unit is the only practical solution.
The part number for the unit is TD060-59994 - Internet search returns price numbers like $8,800. If a dealer installs it, add another few $k for labor (open-station or cab?) plus normal replacement parts like clutch, shaft seals, filters fluids etc. The repair may come close to what the tractor's market value would be (if fixed).
When the prior owner of my L48 decided to sell it rather than pay a huge repair bill, one factor was the extra labor caused by the machine's subframe. Yours doesn't have that but the HST cost is now 180% of what the prior model HST was then. I bought my L48 knowing it needed an HST job - it was only slow in reverse - so I took a chance that most of the high dollar assemblies inside were still good - they were. (and it's still going fine)
If you are mechanically handy there are some other ways to go. Used HST's are extremely rare and hard to find. But if one can be located it should be well-below the new price. If we could come up with a used one I'd bring over a 12-pack and we could give it a go? -pretty far away - maybe texting would work better! Talk more soon - take care, Dick B
This HST is the next generation after the one in my L48. It's redesigned for the L30 tractor models but the operating principles are the same. They have very high-precision internals and rely on perfectly clean fluid. They usually last a VERY long time without trouble. But the smallest metal fragments can ruin the mirror-finish surfaces on the slippers, swash plate, valve block etc. So when they stop functioning the damage is often extensive and a new unit is the only practical solution.
The part number for the unit is TD060-59994 - Internet search returns price numbers like $8,800. If a dealer installs it, add another few $k for labor (open-station or cab?) plus normal replacement parts like clutch, shaft seals, filters fluids etc. The repair may come close to what the tractor's market value would be (if fixed).
When the prior owner of my L48 decided to sell it rather than pay a huge repair bill, one factor was the extra labor caused by the machine's subframe. Yours doesn't have that but the HST cost is now 180% of what the prior model HST was then. I bought my L48 knowing it needed an HST job - it was only slow in reverse - so I took a chance that most of the high dollar assemblies inside were still good - they were. (and it's still going fine)
If you are mechanically handy there are some other ways to go. Used HST's are extremely rare and hard to find. But if one can be located it should be well-below the new price. If we could come up with a used one I'd bring over a 12-pack and we could give it a go? -pretty far away - maybe texting would work better! Talk more soon - take care, Dick B
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rbargeron
Well-known member
Lifetime Member
Equipment
L5450, L48, L3250, L345 never enough attachments
I may be criticized for suggesting this, but it might work to drain the trans oil and replace it with straight SAE 30w oil. I know, I know, Kubota's magic UDT is the only approved oil! But that flies in the face of many hydrostatic drives that work just fine with regular 30w oil.
Kubota's clearances (actually Kayaba's) are very small and synthetic 10w oil is recommended. But in this case, the small clearances have apparently been worn bigger. Heavier oil may work better.
Its worth a try - and won't damage anything. And if next winter it's too stiff to flow, you can always drain it back out and try 20 weight instead. Dick B
Kubota's clearances (actually Kayaba's) are very small and synthetic 10w oil is recommended. But in this case, the small clearances have apparently been worn bigger. Heavier oil may work better.
Its worth a try - and won't damage anything. And if next winter it's too stiff to flow, you can always drain it back out and try 20 weight instead. Dick B
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Boy i sure do appreciate all of your advice. i will pull the plug an see what is on the magnet on the filter and go from there. Thanks for all of your time.
rbargeron
Well-known member
Lifetime Member
Equipment
L5450, L48, L3250, L345 never enough attachments
You're welcome - glad to help - HST stuff is interesting to me anyway.
Let us all know how this turns out. As the HST fleet gets more age on it, more people will be noticing even the best machinery doesn't last forever. Dick B
Let us all know how this turns out. As the HST fleet gets more age on it, more people will be noticing even the best machinery doesn't last forever. Dick B