No hydraulics for hoe or loader after fluid change

[Carpenter98]

Hi All

I'm new here, and new to owning a Kubota. I have used many other mini backhoes in the past, as well as Kubota mini-excavators, so I am not new to the brand. I do have a JD 2305 for yard work and chores but I bought the B21 for the backhoe and the larger size.

I picked up a used B21 w/ BT751 hoe recently. Today I changed the hydraulic fluid & filters as well as a few other maintenance items. When I got on it to move it, it would drive forward and reverse, but the hoe, loader and power steering would not work. I called Messicks (Kubota dealer) and they gave me a few suggestions, but nothing worked.

I cycled the steering and all the other controls to try and purge air. Nothing worked. I drained some fluid out and tried again. Still nothing. I don't know what else to try. I was able to get it onto my trailer and will try and get it in for service this week, but I need it to dig out a job with next week so I'd like to get this solved.

I used all Kubota filters & UDT fluid. When I drained out the old fluid it was a dark grey color. I'm not sure it that was due to contamination or if the previous owner used some off brand by fluid. All functions worked before I changed the fluid.

Any ideas what I should look at next?

Thanks in advance!
Jeremy

 

[Stumpy]

First guess would be the pump lost it's prime.

Without a gauge the way to test for prime is to remove the outlet pipe or if you've got a priming plug you can remove that too. Then if the pump is hooked to the crank directly (front pto) turn it over with the compression release and\or the fuel shut off pulled and see if you're getting flow from the pump. If it's on the rear PTO you probably can't use the starter with the PTO engaged in which case you're going to have to start the engine and flip on the PTO. Spin it as little as possible minimize your mess.

Either way if you get flow fluid prime isn't your problem. If you don't then there are two ways to reprime I've heard of. First method is to remove the inlet pipe and fill with fluid and reattach. You can try and start then but I'd add some more fluid to the top of the pump, reattach the outlet pipe and wait over night to be sure it primes.

The other method is to remove the outlet tube on the pump, likewise a priming plug works just as well, and then fire the machine up. With the pump turning take a blow gun and a rag to seal it and pressurize the transmission sump(or if it uses a separate sump that) to force fluid up the inlet tube. Be careful you've set your air compressor regulator to 5 PSI or less. The transmission is stout but was never designed to deal with internal pressure.

 

[Roadhammer]

My tractor has an intake screen for the hydraulics. Don't know if yours does but you might want to check that the fluid change hasn't sitirred up sediment and blocked the screen. Just a thought.

 

[Bulldog]

My first M 9000 gave me a scare at the 50 hr service. After changing the fluid it had no steering. First thought, HOLY CRAP WHAT HAVE I DONE. Called my dealer and started to explain what happened. As soon as I said fluid change he said no steering. Long story short, He said to idle the tractor at about 1500 rpm's for 10 to 15 minutes. I did and the steering came back on it's own. Hope this helps.