Loader all of a sudden has no down pressure

[Timber]

I have a b7610, was out working with is and it was working fine and then the loader wouldn't drop with pressure. When I push the joystick the loader doesn't mover. It will lift fine dump and curl fine but will not drop under hydraulic pressure. It will only drop if I push it into float and then gravity will let the loader drop. When it is on the ground and I tip the bucket it will lift the tractor. Any thoughts on this. The quick disconnects appear to be working but 1 was a little sticky.

 

[WilcoKubota]

Maybe you can swap the up/down hoses and see if the problem is changed.

Wilco

 

[J_J]

Re-seat the QD, sounds like one of them in not seated.

Swap hoses to check.

 

[Timber]

I'm thinking one of the of the QDs is bad. I'm picking up 1 set tomorrow. It's my dads tractor.

 

[Timber]

No still no luck I am still waiting for a QD because 1 has a seized collar but its in the dump and curl. I did get a coupler to bypass the lines individually. I'm thinking that as soon as I get the new QD ill pull my tractor next to it and mover the lines from his tractor to mine and see if the loader operates with down pressure and go from their.

 

[J_J]

Switch the curl hose and check the lift cyl for lift and down pressure.


You are simply pushing fluid into the cyl to test cyl integrity. If the valve spool is good and the cyl is good, then the cyl should be able to raise the front wheels off the ground.

A coupler instead of the QD's should have given you the answers you need.

Are you trying to do this in the regen mode?

Are you using curl down to raise the wheels off the ground.

If you are trying to raise the tractor, try tilting the bucket straight down, and then push the lift arms lever for down force.

 

[sweettractors]

Have you checked your hyd fluid level in the tractor. Any possibility there is air trapped in the system? Ken Sweet

 

[J_J]

From what the poster said, there is flow in one direction, but not the other, and that is related to QD's

The QD's are not passing fluid in both directions.

 

[Timber]

I'm still going with a QD as the likely problem, the tractor has been sitting for some time, my Dad bought it just over a month ago. I was using it and all of a sudden it simply had no down pressure. The only way to lower the loader once it is up is putting it into float and gravity will bing it down. 1 of the QDs the release collar is seized but the hydraulic fluid does flow. I have 1 coupler and replaced it on both QDs 1 at a time but it didn't change anything.

 

[J_J]

This is not making sense at all.

If you remove both hoses going to the cyl and put them in a bucket, and move the lift arm lever up and down, do you get flow in both directions?

The fluid does flow in one direction due to the fact that you applied fluid to the base of the cyl and it raised, but can you verify that the fluid from the base is flowing back to the tank when you retract the cyl rod.

Otherwise, can the fluid make a round trip? You should be pushing fluid back and forth. ???????????

 

[Timber]

I'll go at it again tomorrow, I'll give that a try, thanks for your help, I living and learning here

 

[Timber]

Ok the mystery is solved, as it turns out their is nothing at all wrong with the tractor. The tractor has a backhoe on it on the lower 3 point arms. While pushing back brush with the loader I pushed the lever engage the 3 point hitch in the open position. With it in the open position is siphoned off enough hydraulic pressure to cancel the down pressure on the loader. Overlooked the obvious and assumed it had to be a flow function.

 

[Muldrick]

I have a b7610, was out working with is and it was working fine and

I have a b7610, was out working with is and it was working fine and then the loader wouldn't drop with pressure. When I push the joystick the loader doesn't mover. It will lift fine dump and curl fine but will not drop under hydraulic pressure. It will only drop if I push it into float and then gravity will let the loader drop. When it is on the ground and I tip the bucket it will lift the tractor. Any thoughts on this. The quick disconnects appear to be working but 1 was a little sticky.

 

[Muldrick]

I have a b7610, was out working with is and it was working fine and then the loader wouldn't drop with pressure. When I push the joystick the loader doesn't mover. It will lift fine dump and curl fine but will not drop under hydraulic pressure. It will only drop if I push it into float and then gravity will let the loader drop. When it is on the ground and I tip the bucket it will lift the tractor. Any thoughts on this. The quick disconnects appear to be working but 1 was a little sticky.

I’m sorry to open up a 11 year old post but I have the same problem with my B 7800. I have swapped the bucket and the dump hoses to which I only have bucket up even though I try to get it down. In other words, when I move the joystick left and right, the bucket only goes up, no down. When I move the joystick up and down the bucket does tilt forwards and backwards.
I have checked all the QD’s and they are fine, I have disconnected and reconnected then.

 

[wdchyd]

Check your 3ph control lever, it might stuck in the up position, not allowing any return line flow out of your FEL control valve.