Air in bucket and boom actuators

[RWey56]

BX23S. Installation of 3rd fn valve last weekend realizes a lot more air in the FEL, particularly the bucket cylinder. The system has no leaks. The manual says "Repeat raising and lowering the boom and bucket operations until all the air is removed from the system and the system responds properly." It's not working. I can step on the bucket edge when its tilted up and compress the cylinder a good 3/4". Air.

As for the bucket, it's pretty obvious where the air is trapped. I'm thinking of detaching the cylinder from the bucket, parking upward on a steep hill, then pivoting it up where the hose connection is the high point in order to chase out what must be a gigantic pocket of air. Not sure how to purge the boom cylinders, but they're not as bad.

Any suggestions welcome.

 

[North Idaho Wolfman]

Are you trying to purge the cylinders with the tractor idling?

If you are put the throttle up to PTO speed and try again.

 

[RWey56]

Are you trying to purge the cylinders with the tractor idling?

If you are put the throttle up to PTO speed and try again.

I wasn't idling, but certainly didn't have it at PTO speed. I'll give that a try. Thanks.

 

[Kennyd4110]

In addition to what NIW wrote, be sure to hold the joystick for about 5 seconds in each direction a few times forcing the system into relief, this will help push the trapped air past the cylinder seals.

 

[RWey56]

OK, there's something I don't understand.

I cycled the bucket at PTO speed several times, put the boom in float to lower it to the ground with the bucket curled back, engine idling. The cutting edge was about 3" off the ground, and when stepping on it, I couldn't extend bucket actuator at all. All the air out of the system ?

When parking it in the garage, I had the boom up a couple feet and the bucket curled up a bit, then shut the engine off. Then, I lowered the boom by floating it, then neutralizing the stick. This time, when I stepped on the bucket, I had no problem extending the bucket actuator until the cutting edge hit the floor. This was about 1/2" extension on the actuator.

Why would the bucket hydraulics relax when the engine is off? The boom nor the backhoe do this. Further, the bucket will hang where you leave it with the boom up. You can put them in any position, shut the engine off, and they'll generally stay where you left them. Does this relax of the bucket hydraulics have something to do with floating ... after the engine is off?

 

[RWey56]

In addition to what NIW wrote, be sure to hold the joystick for about 5 seconds in each direction a few times forcing the system into relief, this will help push the trapped air past the cylinder seals.

You sure about that? I thought over-pressure cracked a bypass valve. You shouldn't really be able to blow anything by the seals, should you? Admittedly, I don't know that much about modern hydraulic details.

 

[Kennyd4110]

You sure about that? I thought over-pressure cracked a bypass valve. You shouldn't really be able to blow anything by the seals, should you? Admittedly, I don't know that much about modern hydraulic details.

1000% sure.
The PRV (pressure relief valve) is set to protect the system components. Going into “relief” is just normal operation when using a loader.

The air may be coming from the “regen” circuit, do a search here on the forum for that term for some reading about it. Sorry I can link now, I have limited access as I’m not home.

Air molecules are smaller than oil molecules and can easily be pushed past the seals.

 

[RWey56]

1000% sure.
The PRV (pressure relief valve) is set to protect the system components. Going into “relief” is just normal operation when using a loader.

The air may be coming from the “regen” circuit, do a search here on the forum for that term for some reading about it. Sorry I can link now, I have limited access as I’m not home.

Air molecules are smaller than oil molecules and can easily be pushed past the seals.

Interesting. So much new stuff to learn with this BX. Thanks for the info.

 

[North Idaho Wolfman]

RWey56, just so you know, Kennyd4110, is probably the most knowledgeable person here when it comes to hydraulics, he does it for a living!

 

[RWey56]

So far I've been impressed by the knowledge base here. It's a good resource and a courteous environment.

 

[Kennyd4110]

So far I've been impressed by the knowledge base here. It's a good resource and a courteous environment.

Yes, pretty good bunch of guys here for sure!

Read post's #3 and #4 in this thread, it explains Regen pretty well. I had though I made a thread on it but I couldn't find it. I'll have to work on that.

http://www.orangetractortalks.com/forums/showthread.php?t=12444&highlight=regen


Unfortunately with all the diesel DPF threads now searching for "regen" does work as well anymore.

 

[Kennyd4110]

RWey56, just so you know, Kennyd4110, is probably the most knowledgeable person here when it comes to hydraulics, he does it for a living!

Well not quite NIW, but I appreciate the compliments. Your a pretty sharp cookie too though