Cleaning Heidelberg filter

2 or 3 possibilities. (OF COURSE genuine original spec, replacement, ideal!!) but IF all else fails, replace with Steel Wool, but as its name implies just that, NOT Stainless, usually turnings from production lathe with mild steel,?? being such and having vast amounts of air/atmosphere passed through will eventually rust? and sucked through the system.… Better yet and possibly the original, factory method fine woven Brass Guaze *thimble* containing/retaining ordinary felt pad, i.e. fine, felt, filter retained by BRASS cage, removed washed out with spirit in seconds, as/when.??? . . BRASS *thimble* easily reproduced, by forming over the handle of most kitchen cooking utensils, or small hand held tool handles!!! Been done many times, British Thompson platens have basically same principle.?
No Brass Gauze available, NO PROBLEM, Ordinary Flour Sieze (*borrowed*) from Kitchen, always stainless steel, always fine mesh, food grade etc.?? BUT N.B. Extreme CAUTION, the aforementioned Flour Sieves are normally located in close proximity to BIG SHARP, Kitchen Knives, the author still speaks at a fairly low register.?????? Further option(s) ordinary (*borrowed* from the family Kitchen) small piece of woven NYLON pot scourer, (virtually bullet proof) in place of brass thimble, and felt primary filter, again removed washed out in seconds.??

One more possible option, with, hopefully/possibly, garden machinery store close, purchase & scale down, the system, used to filter the air, on the intake of petrol, mowers, strimmers, leafblowers etc, i.e. normally, contained in the air intake tract, comprising fine weave Nylon membrane, + coarse foam, pad + fine foam pad.

In essence VERTICAL MEIHLE,S employ exactly this system on the intakes to the vacuum pumps, just bigger.??

Pump filter just dunk it in a bean can with adrop of spirit and swill it about a bit and blow line the residue out backwards and repeat a few times . The reason these are often battered is that minders often ran boiling water and stripper bath for them and then smacked them against the back of the press (usually the ink fount cover plate to shock the moisture out ). Dunk it in some clean oil and wipe the excess off with a rag and screw it back in again .
the thimble at the front just the same but an old tooth brush usually helps so youll be sneaking around the bathroom too.
Replacements are still available but have never tried rebuilding one !

Thanks Peter. This exactly the kind of technical, knowledgeable information I am dying for.

Unfortunately it’s a little too much for me actually - I will spent a day with the press applying what you said and come back with more detailed questions.

So you’re saying the best thing to do is replace the filter with fine brass gauze? What is the “thimble” you keep referencing?

Likewise, there is no reason to replace the steel-wool-like filter, I can just wash it out with spirits?

The filters are normally blocked with paper dust and other soluble dirt and oil , spirit shifts the oil and boiling water breaks out the paper it is possible that there may be gum arabic in it too if the press had a wet set off sprayer ,
the thimble filter is in the end of your vacuum hose at the pick up arm area of the press ,follow the vac pipe away from the arm it is held in with the ali screw in fitting that attaches the hose to the control block ,unscrew the pipe and fitting and you will see it . It is part number T 1667
and looks like a thimble .