Loader LA403 bucket will periodically lose pressure and "bounce" when under pressure

[tanksrcool]

LA403 bucket will periodically lose pressure and "bounce" when under pressure

My Kubota B7800HST with LA403 loader works fine 99% of the time but will periodically "bounce" (suddenly lose pressure then quickly recover) when I'm using down pressure with the bucket when the front of the tractor comes off the ground... other times, 99% of the time the kubota works fine and will lift the front of the tractor smoothly several feet off the ground with no problem. When it happens it seems to lose all pressure, will come down suddenly then instantly start lifting again and will "bounce" a few times then will start working fine.

Also let me add, I've been hauling dirt and I don't have any problems lifting and hauling, I don't lose any pressure and everything seems to work fine with hauling/dumping.... it's only when I use the bucket to lift the front of the tractor off the ground it seems.

I'm thinking the problem is with the relief valve (YW233-95100) in the valve control assembly (YW244-00100) just below the control lever? Any thoughts if this might be the problem, or something else?

Thanks,

Brian

 

[100 td]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

Going into float a little?

 

[ozzie tractor]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

^^^ thats exactly whats happening. possibly pushing the lever too far and starting to hit float, which dumps all hydraulic pressure to tank from both the pump and the rams.

 

[Kanook]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

Yup!...Sounds like you are pushing the stick a little too far forward and engaging the 'float' position....like the responses above say.

 

[Leejohn]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

It's the load checks and the loader is getting air in it. Both well let it do that, just run loader all the way up and down. Mine does it some times, I think is more air then the load checks. I just keep on trucking it well be ok.

 

[tanksrcool]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

Going into float a little?

I wasn't aware that it would "float" like that... I'll test it out and see; thanks for all the feedback!

 

[ozzie tractor]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

these loaders dont have load check valves

 

[Leejohn]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

I hate to say you are wrong, but the B7800's used 3 different valves and all 3 have load checks. I sure would not want a loader valve without them.

 

[allenjack]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

My L4400 with a 703 loader does not go to neutral when I release the controller.The bucket continues to go in the direction last taken. This is annoying when you are moving the tractor backwards and forward and forget to move the stick back to neutral

 

[Leejohn]

Re: LA403 bucket will periodically lose pressure and "bounce" when under pressure

The 1st thing I would do would be to pull the caps off of the end of the spool. Check for broken spring, dirt, and rust. Then the joystick linkage for wear and adjustment. If you have a cab then check your cables.