After only a couple of uses my little Mono started leaking again. Took it apart and found this ... quite probably a lot to do with tardy workmanship the last time I took it apart ...
Note the little lump of brass embedded in the ceramic face. The brass static half of the seal was quite badly scored too.
Scared of Mono's spares prices and knowing I'd got nothing to loose I decided to have a go at refacing the seal.
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The static half of the seal simply sits in a rubber bush in the pump housing and is quite easy to push out.
(photo shows static half after sanding)
This was done by gently sanding the face of both seal halves on 800 grit wet and dry paper backed by plate glass. I used a little water and washing up liquid to lubricate things. Both halves were then lapped for quite a time direct on the plate glass using T Cut. This seemed to work quite well ...
The parts were cleaned thoroughly, lubricated with a little bio and reassembled. Reassembly was made much easer by turning a small chamfer on the spigot of the static half, to help it enter its rubber housing (in the absence of a lathe the chamfer could easly be filed with a little care).
I've only run the pump for about 5 minutes tonight but it would appear that against all odds the seal is holding ... yet to see if this will last! I might run a book.
