420 e backhoe

[hectord9]

hi i have a backhoe 420-e backhoe and while driving and in bucket ride control on bucket creeps down. any help would be appreciated

 

[Equipmentguy224]

You may need to repack the cylinder which moves the bucket

 

[heymccall]

Is the bucket curling open, or is the boom drifting down, when this occurs?
And, your serial number prefix, ie. KMW, or the like, please.

 

[hectord9]

Is the bucket curling open, or is the boom drifting down, when this occurs?
And, your serial number prefix, ie. KMW, or the like, please.

no it does not curl up just drifts down ser # PRA00285 and i already replaced ride control solenoids and valves. ride control system work as it should except for the bucket drifting down, and only does it when the ride control is on and traveling. thanks for your help

 

[heymccall]

Here's the diagram


Following the circuit to the top solenoid, you can see the barrel pressure dead ends at the accumulator, so, even though it only drifts with ride control on, I'd still inspect the boom up relief, and verify that the boom spool isn't scored or damaged.

 

[heymccall]

One second thought, on one of my KMW 420e, I had drift only under heavy load. There are revised lift cylinder seals. The original ones removed were rock hard, where the updated ones are pliable. Someone above suggested repack of the cylinders, too.

 

[hectord9]

One second thought, on one of my KMW 420e, I had drift only under heavy load. There are revised lift cylinder seals. The original ones removed were rock hard, where the updated ones are pliable. Someone above suggested repack of the cylinders, too.View attachment 181565 View attachment 181566

heymccall. thank you for your help, first time using a forum and appreciate your help

 

[hectord9]

Here's the diagram
View attachment 181564

Following the circuit to the top solenoid, you can see the barrel pressure dead ends at the accumulator, so, even though it only drifts with ride control on, I'd still inspect the boom up relief, and verify that the boom spool isn't scored or damaged.

heymccall where is the boom up relief boom spool located, you mean in the solenoid block where the 2 valves are located?

 

[heymccall]

Forget relief and spool. Repack your cylinders. The bobbing action of the ride control is exaggerating the leaking at the piston seals.