New member. After a hard push against a dead tree the bucket on my LA450 will curl out but not in. The reason is the fluid from the un pressured side is not releasing. In other words there is pressure on both lines when curling in. I have swapped the lines and the same thing happens when the loader is raises but will not lower. I have determined it is in the valve. I did this a couple of years ago and I was able to free it up somehow but not this time. My theory is that the pressure from the pushing against the tree increased the pressure in the system well above the 2000 psi and blew something in the valve blocking the fluid return when curling up. Has this happened to anyone else?
LA450 bucket curls out but locks coming in.
- Thread starter BubbAQ
- Start date
I am doubtful of that diagnosis.
For one you cannot reverse the lines on the bucket - that will most definitely prevent the bucket from curling. With the lines reversed it will extend in both dump and curl positions.
Dan
Thanks for the reply Dan,
Maybe I was not clear on the "reversing of the lines".
At the valve I swapped the 2 lines on the bucket port with the 2 lines on the raise/lower port.
The same thing happened but with the raise and lower. It would go up but not come down. Yes you can reverse the lines on a cylinder and it will still work but the action will be reversed on the lever.
The problem is that when curling in the fluid on the non pressure side of the cylinder is blocked and not returning to the tank. When curling out, the fluid goes in the pressure and our the low pressure just fine.
Even with the tractor not running there is pressure on both lines after an attempted curl in. Moving the lever side to side does not bleed off the pressure.
Maybe I was not clear on the "reversing of the lines".
At the valve I swapped the 2 lines on the bucket port with the 2 lines on the raise/lower port.
The same thing happened but with the raise and lower. It would go up but not come down. Yes you can reverse the lines on a cylinder and it will still work but the action will be reversed on the lever.
The problem is that when curling in the fluid on the non pressure side of the cylinder is blocked and not returning to the tank. When curling out, the fluid goes in the pressure and our the low pressure just fine.
Even with the tractor not running there is pressure on both lines after an attempted curl in. Moving the lever side to side does not bleed off the pressure.
You CANNOT reverse the action of the bucket spool by reversing the connections. It is a regenerative circuit and the regen port on the valve must be connected to the rod end of the cylinders. If you reverse the ports you will put the cylinder into an extend only mode. Doesn't matter bucket or boom the result is the same.
Dan
Ok, forget that I reversed the lines as a diagnostic measure. They are back to normal. The loader seems to be in an extend only (Curl Out) mode. What do you think the problem is?
I don't know but fist thing I would do is swap those bucket couplers just to be sure they are correct.
Dan
Another possibility is the tsnk return line between loader valve and tractor is not properly connected. Bucket curl is the only function that uses that part of the circuit and if its blocked the bucket cannot curl.
Dan
That's exactly what it was. Something must have caught the quick connect and barely released it. The good news is the valve is REAL clean! Thanks for your help Dan. Oh and another symptom that I found was when you raise the loader and push the lever to float, it stays up.
Congratulations - thanks for following up. Glad it was simple and inexpensive !!
Overlooked float when thinking about what functions used the tank circuit. Float connects pump and all four work ports to tank so that would block the cylinders both directions as well as deadhead the pump. I will make a note of that.
Dan