Brand FEL valve leakdown.

[NuJinma]

On 4 year old Jinma 254 I have a Brand Hydraulic Loader Valve (Model PLV22RFSTKAB if anyone is an expert on them). This is a joystick 2 spool open centre valve with regeneration rated for 10 GPM, with adjustable relief preset at 2000 PSI. Spool actions are regeneration with spring-centering and 4th position float. It has never worked well, When lever pushed to regen, it would shudder badly and dump even slower than the usual controlled dump.
In the last year the other spool (boom raise and lower), has started to bleed down, first when heavily loaded, now even when unloaded. Yesterday I took it apart, cleaned out as I thought it may have some particulate lodged in the works. no such luck, but no problems found in the problem leaking spool. (The other spool had quite a bit of wear and scratching, but still works well).
Anyone have any thoughts?

 

[J_J]

Leakage is going to happen sooner or later, and yours came early. It is difficult to rebuild spools, but you can redo the o-rings, When a spool wears, even putting a new spool may not fix the problem. You could put check valves on the lift and dump. My lift arms will leak down over night. As long as it remains useful for what I am doing, I will use it until it gets overbearing. Did you happen to clean the relief circuit in the valve? You could use a hyd gage to see if you have the pressure specified.

 

[Egon]

Could it be the hydraulic rams?