lw6 prv problems

[intheground]

I have a jima 284 with a lw6 backhoe. I believe I have a sticky or dirty prv on the boom lift valve. (when I lift the boom out of the hole, no power and the pump squeals) could someone help me with location cleaning and adjustment of the prv.
thanks

 

[J_J]

Is the pump squealing or the relief valve going off?

 

[intheground]

Is the pump squealing or the relief valve going off?

believe the relief valve is going off. the fluid gets hot

 

[J_J]

believe the relief valve is going off. the fluid gets hot

What else is in the hyd circuit? Could one of the other valves be sticking. Are the other cylinders moving at all. Put all the levers to neutral and jiggle them to make sure they are in neutral, and exercise each cylinder to see which spool is causing trouble. The relief valve going off a lot will definitely heat up the oil, and you want to keep the hyd fluid below 200 preferably around 180 degrees. Maybe the relief valve is stuck open, If possible take it out and clean it.

 

[intheground]

What else is in the hyd circuit? Could one of the other valves be sticking. Are the other cylinders moving at all. Put all the levers to neutral and jiggle them to make sure they are in neutral, and exercise each cylinder to see which spool is causing trouble. The relief valve going off a lot will definitely heat up the oil, and you want to keep the hyd fluid below 200 preferably around 180 degrees. Maybe the relief valve is stuck open, If possible take it out and clean it.

nothing else in the circut just the back hoe . runs off pto pump. the other controls work. just the boom lift given me trouble. when I lift out of a hole no power and can hair difference in pump sound like I was holding it on at the end of a stroke. when I lift the boom it will even start to drop even with the control engaged. oil gets hotter than 180. that's what it seems like the valve is stuck open. could you give me some direction on location and taking it apart. fairly new to hydraulics expect fpr owning a jinma and the usual problems

 

[J_J]

Try this before you take the valve apart, switch the hoses with the bucket cylinder and see what happens. If the problem switched to the bucket, then that spool needs cleaning, if it has o-rings, it can be rebuilt. Most valves are made to close tolerances, and you can not just go and get a spool of the shelf. You might wind up putting a new spool in a worn barrel, etc. I don't know how old your BH is, but a new BH valve set may be required.

This is going a little far, but it is possible. If that valve has a PB port, theoretically, you could add a single valve and plug off the old port to the boom, or shift the boom to one of the other outlets.