Hi Com_VC, Guys,

Yes there is

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Its a bit difficult to see in this picture ! But when I stripped the shock absorber down there were quite a number of washers associated with the piston. The flat washer up against the piston is the non return valve.

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A lot of these are just shims that are placed between the large washers to control the flow of oil between each side of the piston. Some of the large ones are 8 or ten thou thick, some of them are perforated in various ways.

If you look at the picture, on the bottom left hand side you will see a 10 thou thick washer that has two slots in it near the centre. That is the washer that I finally chose to fit on the piston rod side of the piston.

It will behave like a non return flap valve, allowing oil to flow through the piston and not round through the flow control valve when the bandsaw arm is lifted. The other way the washer will close off the vents through the piston preventing oil flowing that way forcing the oil through the control valve.

At least that is the way I expect it to function, but I wont find out until I fill it with oil.

Talking about the hydraulic oil would the ATF stuff be OK ?