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My a/c has been in the hangar for at least two
weeks whilst we worked on an oil cooler problem.
When we closed it up and were doing the preflight I
noticed the "Down" pressure gauge was showing zero but the pump refused to
run. On closer inspection I realised the needle was pegged against the
stop and was registering 1000psi ++
I opened the emergency gear extension cock a hair,
bled the pressure down to 400psi and the pump kicked in and brought it back to
550psi. Pressure switch works ok obviously. The hangar is heated to
about 55F.
We flew the a/c and the gear worked well, no
problem. Where this pressure comes from beats me as with the gear down the
HP side of the system is at zero and the gear select is in the down
position. The safety switch I have will not allow the pump to run to
retract the gear.
Curiouser and curiouser to quote Alice in
Wonderland.
Ian Crowe.
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