B26 won稚 stick in and boom out at the same time...

[Smokeydog]

From my recent 400hr super UDT oil change, new filters, and new pump suction line replacement could not tell there was any air to bleed. No noise, no jerking, no problem. ~7+ gallons to refill system. 5 gallon buckets of new oil.
Oil supply to the pump comes from lower right hand side of the tank at the filter housing. It would take an awkward position to lose oil supply. Another post reported they had damaged that filter housing by ground debris.

Air in your system now is getting in somehow. Rubber elbow likely suspect. Backhoe leaking down when parked might be letting air leak in. Note any exterior leaks from lines, fittings or cylinders? Didn’t you recently add a thumb valve?

 

[freezerburn]

No leaks and the problem was occurring before the added thumb. According to your B26 manual What position should my rams be in when checking the dipstick? My Kubota B26 WSM is very fundamental with no real specifics. I know I didn稚 put in the full amount of udt2..

 

[Smokeydog]

Just trying to get some patient history to better diagnose the problem. No worries .

Hopefully you can see how to check transmission fluid level from the operator’s manual.
Flat surface, lower implement and engine off. Important! if using the bt820 backhoe, flat service and set backhoe as shown, up in transport mode, outriggers up.

That **** dipstick is hard to get a good reading. It goes into a tube that goes into case. The ring bumps that indicate proper level range can scrap the sides tube giving false readings. That’s why I ground a flat on the round plastic dipstick. Still I have to check several times to make sure I get repeatable readings on nearly invisible oil. One of most tricky dipsticks I’ve had to learn to use.

 

[freezerburn]

That痴 good right there thanks a ton. Can you post the part about the other two bolts to drain etc that was mentioned earlier on in the posts?

 

[Smokeydog]

Good drawing to show you where the plugs are but hard to access the rear plugs (2).

The hydraulic filter change every 400 hours with the UDT change.

HST filter change every 200 hours.

 

[freezerburn]

Alrighty then, so do I need to refrain my fresh udt2 and filter because I didn稚 know about the other bolt only the one under the tank. Also, I知 not seeing the other (3rd) backhnbolt you mention and there are only two in the pic you just posted..

 

[Smokeydog]

On the axle drains the picture shows one bolt for (both sides).
I got 1-2 quarts out from the rear axle after draining the main tank. Roughly 7% of the volume. Probably at least that much in the lines, cylinders and low spots. So if routinely maintained and not severely contaminated I think you are fine till the next 400 hours. Have you collection of 12mm wrenches ready. It’s were a flex gearwrench earns it’s keep. What the picture doesn’t show is all the steel frame around axle.

On my old B20 those axle drain plugs were plastic bolts with O-rings that faced the rear.

The rubber elbow on the pump suction side can be changed with little oil loss. If split, it allows oil to drain back to tank anyway having a slug of air at each start up. If you replace the whole suction line (updated design recommended) there will be more oil loss as the rear of the metal piping bolts to the hydraulic filter housing.

My friend complained how often this rubber elbow was failing on his new B26. Caused me to buy the parts and inspect while doing the 400hr maintenance. I was shocked how spilt the elbow was after removing. Achilles heel of the B26.

 

[the old grind]

I've often wondered if my Terramite's pads drifting down was pulling air into the system.

That T5C has separate pumps for HST & cylinders, and open center system, air in hydro might be purged too quickly to be noticed.

 

[rScotty]

I've often wondered if my Terramite's pads drifting down was pulling air into the system.

That T5C has separate pumps for HST & cylinders, and open center system, air in hydro might be purged too quickly to be noticed.

I've wondered the same thing when the outriggers or the bucket drifts down. My guess is that it is fluid going both ways past the control valve.

 

[Smokeydog]

Air in a hydraulic system can cause some mysterious symptoms. Sometimes replacing parts fixes the leak and good parts get the blame.
When troubleshooting have often wanted a way to visually see the oil during operation. I could only tell if it was foaming more than usual. As tractors get more complex adds to potential problems.
On the B26 it has about 1” rubber plug for adding oil. Thinking of ways to add a window thru the plug. Record using a smart phone’s light and camera during real time operating conditions. A borescope might work. Then again might not be able to tell much.