Loader doesn't hold hydraulic pressure

[keith841]

I have a 2006 TYM T273 with 1735 hours. Over time the hydraulics have held pressure less and less. Even when the tractor is running if there is any weight at all I can watch the bucket go down. If it's full of gravel or something very heavy, it goes down rapidly. Over night it's on the ground as well as the back hoe. My questions are;
1. Is there an adjustment?
2. How do I check the pressure and what should it be?
3. How do I determine if the pump is worn?
4. Where is the pump and can I do this job myself?
Thanks for any help anyone can provide!!!!

 

[oldnslo]

Bucket dropping has nothing to do with the pump. The pump provides the flow for lifting the load while gravity & leakage allow the load to drop.

Points of leakage that can cause this problem.

If the load is in the direction that is causing the cylinders to retract like on most front end loaders there are a couple of options.

1) There is external leakage allowing oil to escape onto the ground.
2) The directional valve is not spring returning to center properly.
3) The directional valve is worn or scuffed. This is not repairable and the valve would have to be replaced.
4) Seals on cylinder piston are worn allowing oil to leak past the piston and then also through the directional valve. BOTH of these must happen for this to allow the loader to drop.

Do have quick disconnects in the lines going to the loader? If yes raise the loader off the ground at a height that you can use a jack to lift it if necessary. Stop the engine on the tractor and disconnect the line going to the rod end of the cylinders. Let the loader sit for a period of time to see if it drifts down. If yes this would indicate the directional valve is leaking. If no this would indicate the seals on the cylinder piston seals are worn and the cylinders require rebuilding.

Use the jack to raise the loader enough to reconnect the quick disconnect so that you can lower the loader fully.

 

[747driver]

Just went through this with my FEL....only it was the bucket that would go to the dump position without touching the joystick. Found one of the bucket cylinders seals damaged. Put new seal kits in both cylinders....no help ! So the next step was to pull out the 2 spool valves and look for damage. No damage, but found the positioner spring loose on the bucket spool which was not allowing the spool valve to return to center....it was staying in the dump position. cleaned and greased the spring along with adjusting the cable from the joystick to the valve. Now it works like new again !!! As oldnslo says....raise the loader up and shut the engine off. Bleed off the hyd pressure and then disconnect the loader boom quick disconnects which is easier than taking a line apart. Start the engine up....if the loader stays up then your cylinder seals are ok. Shut off the engine, bleed off the hyd pressure and then reconnect the quick disconnects. Start the engine and raise the boom, if it starts to go down you have a spool valve problem more than likely. Not a hard job to take apart, clean and adjust.

 

[Tx Jim]

Sounds as if spool valve is leaking internally if no oil leaks are visible. As oldnslo stated ""leaking boom piston seals will not allow boom to lower"" if control valve spool is holding pressure

 

[keith841]

Great advice guys! Thanks. Ok, so where is the spool valve? I have no idea where or what it looks like LOL. Is that the one under the joy stick?

 

[ericm979]

The joystick is connected to the loader valve. Either directly if the joystick is on the loader, or via cables if the joystick is mounted on the fender. The loader valve contains two spool valves, one for lift and one for curl. A spool valve is a type of hydraulic valve.

 

[Tx Jim]

The spools which are a machined fit for correct clearance in housing are encircled in blue.

 

[keith841]

The spools which are a machined fit for correct clearance in housing are encircled in blue.

Thanks!

 

[Dave M7040]

I have a 2006 TYM T273 with 1735 hours. Over time the hydraulics have held pressure less and less. Even when the tractor is running if there is any weight at all I can watch the bucket go down. If it's full of gravel or something very heavy, it goes down rapidly. Over night it's on the ground as well as the back hoe. My questions are;
1. Is there an adjustment?
2. How do I check the pressure and what should it be?
3. How do I determine if the pump is worn?
4. Where is the pump and can I do this job myself?
Thanks for any help anyone can provide!!!!

You need a workshop manual before going very far.
Here is a source for a good WSM for $10 and immediate download

You need to start with this simple test to determine if you have a cylinder problem,
It is a series of simple tests but will tell you a lot.

To test the hydraulic pressure buy a gauge and quick coupler and plug it into a port for a FEL cylinder.

Run tractor at full rpm's and move control lever to send pressure to gauge. Read immediately and then release control lever.

Any independent hydraulic shop can supply gauge and half a quick coupler for about $30.

Without checking, I expect the pressure to be around 2,000 psi.

Once you release a control lever, the hydraulic fluid is locked in the cylinders and any leakage is usually internal in the cylinders and does not involve the valve.

Post some photos of the sides of your engine so perhaps your pump can be located. Do you have power steering?

Again, invest $10 and buy the WSM

Dave M7040