Cat 420e backhoe

Backhoe swing sticking while using keeps swinging after control is released

Post a machine Serial Number please. Does the swing function eventually stop on its own or does it stop only when the swing cylinders reach the end of their travel.?

Dan02221 and they keep going both ways and you can bump the control the opposite way its moving and it will stop and stay where its at its like the spool is not centering when you use the function gently

Has any repair work been done on the hydraulic system recently.? Burst hose, cylinder reseal, that soprt of thing. I'm wondering if a particle of something is jamming the valve spool in the swing section. The only way to find out is to disassemble that section of the control valve. See the attachment. I don't know if you can do a partial disassembly in situ or whether the complete control valve has to come out first before the spool can be accessed. Hopefully someone else can advise you. If you do end up removing the complete valve assembly I would strongly suggest that you reseal both primary and secondary resolver valves in all 8 sections of the valve while you have it apart.

I have pulled the spool out and checked it and let the body drain the oil out but it was no change its still hanging in the valve body

Broken centering spring maybe.?

Well I checked it as well made sure it wasn't broke and retighted the holding screw it all seems good I just wanted to make sure there wasn't anything else before replacing the valve cat wants $2600 for just the part

Hopefully one of the guys more experienced than me with backhoes will chime in but I wouldn't personally be replacing the complete valve section just yet. When you pulled it all apart did you just remove the spool or did you dig into any of the other parts of the swing valve section.? What were all the O-Rings/backup rings like.? If they were original then they date from 2012, so almost 15 years old. They may have gone a bit hard by now.

Just pulled the spool from below did not disassemble the whole stack and yes I agree with the new orings but I haven't taken the block out and apart yet just the cap and spool its all original so it could be a burr or possible a bad internal oring but I was hoping to eliminate a pilot pressure and main pressure before I tore it out it also seems like the hoe part lacks power but again its older and has some hours so it may be just wear and tear thank you for info

Do you have a borescope that you could poke up the spool tunnel to look for any dings or scratches.? A complete control valve reseal might potentially address the low power in the backhoe.