The expansion vessel in my combi has stopped doing its job properly
after a leaking radiator valve reduced the system pressure to almost
nothing the other day.

Last time I found the expansion vessel wasn't doing its job, I managed
to pump 10psi of air into it, and it then worked perfectly for a few
months until this latest event.

This procedure would be easy if I had a suitable (cheap) pump. Any
suggestions? A car foot pump is out of the question because the
vessel's valve is about 5 ft above floor level.

Last time I did it, I had an electric tyre pump which I connected to a
long wire which I then plugged into my car's fag lighter. But it was
very tricky because each time I pulled the pump's attachment off the
valve, the air would escape - and it doesn;t take much air to create
10psi in the vesel.. And now I don't have a car with a fag lighter!

I do have a procket pressure guage which can read as low as 10 psi.
It's just the pump which is the problem.

Thanks for any suggestions. A battery-operated pump perhaps? Anyone
know of a cheap one? Someone told me a bicycle pump would work. Is
that correct?

Many thanks

Rich