Oil & Fuel B26 Hydraulic inleakage

[Smokeydog]

Coming up on 400 hour service. B26, 2016 model. Noted some external leakage at fill plug and dipstick after mowing for several hours at a time. Not much but enough to attract dirt. A friend with an earlier B26 had a worse problem caused by rubber elbow on the suction side of pump. Air was being sucked in causing cavitation and oil aeration. He has replaced that elbow several times with the last one being different material. So as part of my maintenance replacing oil and filters, ordered new rubber elbow 32741-39160 $23. Surprised at the kit when picked up. Not only the elbow but new metal and rubber tubing, clamps and Oring. New design is more alignment and vibration friendly. I could just replace the rubber elbow with current hard tube or replace all the tubing with new design. Parts guy give me copies of both parts diagrams and rechecked. Lot of parts for $23. Usually the surprise is the other way.

All the tubing is included as a kit.

 

[Rayrla]

I have a 2013 B26. When I used mine during January and February oil streamed from the fill tube. After doing some reading I assumed that the suction hose was the problem. When weather warmed up, no more oil from fill tube. Since leak stopped I decided to wait until fall to repair. Because of your post I will order tube now. Thanks.

 

[Dave M7040]

I tried your part number on the Messicks web site and was told the new part number is 32741-97900 replacing your number.

No idea of what has again changed

Dave M7040

 

[Smokeydog]

Got the part number from Messicks web site. 32741-39160 for just the rubber elbow. Did not see the new 4pc design.


May 18, 2020, Ordered from local dealer by phone, invoice part number received; 32741-39150 Replaced.

Part number on bag 32741-97902 Hose,Assy<suction
Kubota sticker, made in Japan

With all the different part numbers even more surprised what I ended up with.

I’m thinking the new 4pc suction line assembly that replaced the old 2pc suction line was done to address air inleakage problems on suction side of the pump with both different materials and design.

Appreciate Kubota for addressing a design issue. Doubt much contact effort given to previous owners of an design improvement. Air like dirt causes cavitation heat, wear and damage to hydraulic components.

 

[Smokeydog]

Replaced the pump suction line with new a improved Kubota version. Suction line external from the hydraulic filter outlet to the suction side of pump.
Rubber elbow kind of buried is the problem. Note only the slightest oil/dirt film. Never enough to spot the floor.

Note the cracks in elbow. These allow unfiltered air to be sucked into the hydraulic pump. Of course the cracks happen exactly where you can’t see without removal.

Note how the old elbow was in strain with the hard lines.

Old line with new line. New designs helps with alignment and hopefully with vibration and thermocycling resistance. Greased all connections with silicone high vacuum grease to be sure all joints were bind free before tightening hose clamps. Lost several gallons of sudt replacing the line. This was part of the 400 hour maintenance anyway so going to completely drain overnight and then go back with new filters and oil.

 

[Dave M7040]

Thanks for the great update.

I find it interesting that the original design used constant tension hose clamps while the kit uses gear clamps.

Dave M7040

 

[woody]

Thanks for the information I had this happen on my B26 but I got just the rubber elbow and then found out it was the seal in the pump. I may go ahead and order the kit and have it on hand for the next time I need to change filter.

 

[Smokeydog]

Thanks for the great update.

I find it interesting that the original design used constant tension hose clamps while the kit uses gear clamps.

Dave M7040

I would have thought constant tension clamps would be better. Can’t over tighten and alway clamping.
Using the screw hose clamps provided by the updated suction line. Fluids and filters all changed. Can’t tell any difference from whine or operation yet. Cleaned the rear of the tractor around fill port. Hopefully will not have oil coming out the fill port now.

Don’t have faith in the rubber elbow. Looked like the same design and material. No reinforcing mesh in the rubber. New hard line design is kinder for alignment so hope it last 400 hours. Probably replace the rubber elbow at the next 400hr service interval.

 

[Rayrla]

Finally ordered my suction hose elbow on 11/3/20 and received the same kit and stock number as Smokeydog. Have not replaced yet. Before ordering checked condition of elbow. It had noticeable cracks on the outside near the end of the metal tube. No leakage that I could find with it still on tractor.
Smokeydog questions for you. Approximately how many gals of oil did you lose? I did my 400 hr service summer 2019 and am trying to decide if I should buy more filters and oil for another service. I have less than 50 hrs since summer 19.
Any helpful hints, things to avoid or make job easier? No documentation came with kit.
Thank you Smokeydog. Anyone owning a B26 needs to be aware of this thread.

 

[Smokeydog]

I didn’t lose oil directly from the cracks in the elbow. Inleakage would aerate the oil and blow oil out the vent, dipstick and fill plug on the back of the tractor. Added a quart several times.

To replace that suction line without draining I don’t know. That line is coming from the filter housing sucking from the tank. So I think their would be significant oil loss. I was performing the 400hr complete oil and filters change so I drained before changing. I was surprised how cracked the elbow was after removing.

Have to remove the rear wheel to access the line connection at the filter housing. Still took a selection of extensions, universal joint to remove and replace the one bolt. It was tight so took time not to bugger up. The rest is easy and the new design doesn’t put stress on the elbow.

Running quiet with no leaks all summer. Even with the upgraded suction line probably be good to replace the rubber elbow at the 400hr service interval. Still would like to find a fiber reinforced hydraulic rubber elbow of the right size.