I've looked all over for either a rebuild kit for the 4 spool hydraulic valve or a replacement assembly without any luck. If you raise the forks they go back down about an inch every 5 seconds. I put a ball valve in line and when I raise them and close the valve they stay up so it's not the cylinders. The valve assembly has a small tag on it that says Parker Model: 1503438 and Serial# H0105 0962. Does anyone know where I could find either a rebuild kit or a new one? Thanks