Loader L3400 HST Hydraulic Filters

[kubota06]

Hi
Have an L3400 that has been acting jerky when steering and the loader is not operating as fast as usual. The jerky just started but loader has been slow for awhile. Is there a hydraulic fluid screen I need to change or just the filters. I can see small amount of fluid on lines on the right side of tractor by the pump
under the floor plate. I change all fluids and filters per manual mid 2009. Changed to all synthetic fluids w/Kubota filters.
Suggestions !

Thanks
Kenney

 

[ccsial]

I think there was a post about a hydraulic line on the right side being cracked and sucking air. I may not be remembering this correctly but I'd check for that.

 

[bullbreaker]

Just as Ccsial stated,check suction return line(rubber hose)by brake pedals.In front of b-pedals make sure clamps tight but probably has a crack. Bota part# tc220-33332 around $25.
Boone

 

[alchemysa]

Dunno about the 3400 but the 3410 appears to have a filter screen on the RH side. Its part 030 in the pic attached. However I think this is only delivering oil to the HST and probably does not effect loader hydraulics which have a separate pump and oil lines. Have a look in Kubotabooks for a manual that may be helpful.
Kubotabooks.com

By the way. Whats the difference between a 3400 and a 3410?

 

[kubota06]

Thanks

Will look into cracked line!
Looking around forum have determined no hydraulic filter screen are
so I am going to change both filters ... Looking into filter cross reference via
forum. No luck through Wix cross reference & I don't like to drive the 30 miles to tractor dealership but will probably end up having to do so.

kenney

 

[kubota06]

Well looks like I spoke to soon!

ccsial,bullbreaker
I will clean and check the hose and clamp w/break cleaner & look for leaks tomorrow morning.

alchemysa
Thanks for those links I spent 30 minutes on the web with no results when all I had to do
was log on to TBN and ask! The 3410 has a little less horse power engine and pto wise, could not tell if differences in hyrdraulics so I will look to see if that tube strainer is in my
suction line as indicated in the manual.

Thanks

 

[crbr]

Well looks like I spoke to soon!

ccsial,bullbreaker
I will clean and check the hose and clamp w/break cleaner & look for leaks tomorrow morning.

alchemysa
Thanks for those links I spent 30 minutes on the web with no results when all I had to do
was log on to TBN and ask! The 3410 has a little less horse power engine and pto wise, could not tell if differences in hyrdraulics so I will look to see if that tube strainer is in my
suction line as indicated in the manual.

Thanks

The strainer on my B7800 is almost invisible due to the fact that it looks like a bolthead that is holding on a lever (as the picture above shows). It is a 26mm sized head. I had to look around to find a 26mm socket, but that did the trick. The pic above is just like the B7800. However I can only suspect that the strainer will not be clogged to the point of flow reduction, but there is only one way to confirm.
If I recall correctly, you can pull the strainer with minimal loss of fluid (due to the fact that the strainer is on the upper side of the fluid pool). Someone here may have a better take on this as I have only changed mine once at the 50 hour service. If you're changing filters, that is a moot point. I would not suspect a clogged filter(s) or strainer before checking the hose. When I changed my fluids at 50 hours, the oil was still clean as a whistle.

 

[kubota06]

crbr
Just spent 10 minutes with flashlite looking .. nothing similiar to picture; but I found the problem. Crack right at bend in 1 1/4" hose going to 1 1/4' pipe leading to I assume suction side of filter. Hose is between transmission block & brake pedals. I will replace hose tomorrow clean it all up and see if this fixes problem.
Still wondering if there is a strainer screen somewhere though.. will keep looking.

I will post results thanks to all of you.

 

[alchemysa]

As I said above, the strainer (part 030 in the pdf) probably doesnt have anything to do with the hydraulics for the loader so dont go pulling the strainer thinking it will solve the loader/steering problem. Older tractors like my 1550 had a strainer on both sides. One strainer was for the HST. The other was for the loader and power steering. (Hence loader/pwer steering problems can appear at the same time.) Newer tractors use spin-on filter cans and have done away with one or both of the strainers. The loader and power steering use the oil pump thats bolted near the front of the engine. It sucks oil through the spin on filter on the right hand side of mid transmission then pumps it at high pressure to the loader, 3ph and power steering. The plumbing from the spin on filter to the pump is where I'd be looking closely. As has been suggested it might be sucking air.

 

[kubota06]

Roger That!!

Problem was exactly as BB described.

link to previous post w/picture of hose

http://www.tractorbynet.com/forums/kubota-owning-operating/122787-l3400-hydraulic-leak.html