Most of the times the upper and lower clutch cilinders in your Dudo will go bad after 40-50 years of use...
We advise you to replace the complete system (both cilinders, the hose, the fluid & small parts) all at once.
Since there is a variation of set-ups as installed by Mercedes, We offer you the correct replacement-set (like on the pictures) when you send us the vin-number of your vehicle during your order.
Because the fluid reservoir of the clutch and the brake system (in this type of vehicle) are often combined, we also advise to check the brake cylinders and/or to replace them preventively together with the three brake hoses...