1934 Houdaille Front Shock?

[AzBob]

Removed front shocks. Have good resistance but low on fluid, it just drips out. Has a heavy gear lube (differential fluid) smell to me. What is recommended to flush with, kerosene, mineral spirits or denatured alcohol? And what to fill with?

Edit: Fluid pools on top of water. Does not appear to mix. Has a honey like consistency. Tends to form globules in water. See photo.

 

[Kube]

I have used mineral spirits with good results. When I have flushed them, I drain the oil, fill with spirits and work the lever back and forth. Then I allow the shock to "soak". Drain and repeat until the "stuff" comes out fairly clear.

You can use hydraulic jack fluid, widely available, in these.

 

[AzBob]

Found out the previous owner had the shocks rebuilt at A-1 Shock Absorber Co. Called A-1 and was told they use motorcycle fork oil for its non foaming properties. 20W viscosity was mentioned as something they commonly use in their rebuilt Houdaille shocks.