Hi Brains. Can't really help you on that one I'm afraid as I've never had a Reliant with a pressure gauge. Personally, if everything sounds O.K, I wouldn't worry too much about it. If you're concerned though, try giving the guys at Michaels of Selby a ring. Reliant spares specialists & all round helpful chaps.
01757-270002.
www.michaelsofselby.commichaelsgarage@btconnect.comAs far as changing the pump's concerned, you can do it in situ, by dropping off the sump. The pump's held by two nuts, (can't remember the spanner size). Not a lot to go wrong with them, but I've got a couple of second hand ones if you need one, (condition unknown).