I have the same problem as Lorn Olsen.  I already have the gauges fitted and
if he has not seen my post about my observations it might be helpful to read
it.  If he no longer has it, E mail me and I will send it.  There was also a
lot of advice from fellow builders and Mark Mahnke of Lanxcair, which was
very helpful.

I can tell you that the problem is most likely not in a cylinder leak across
the high pressure to low or vice versa.  My pressure will hold up over a
weekend and give no problem when operating on the jacks.  All of a sudden it
will kick in and I will get what I call the burps exactly as Lorn describes
it.  I have got rid of it by opening the free fall valve and running the
pump and I have got rid of it by ignoring it.  Either way does the trick.
once the gear is down and overcenter you do not need the pressure so pull
the pump breaker.  See Mark's reply to me as to his recommendations.

If Lorn does want to tear it all apart see Mark's procedure for fault
tracing.  I would be interested in what he finds.

Regards

Ian Crowe.
C-FKRO
Passed final inspection and waiting for the paper work to be able to fly
legally.