B737-200 hyd. snag
Here's a good snag for you 737 classics entousiasts!
I've got an intermittent snag on one of my B737-200, and it's a real head scratcher. Here it is:
Sometimes on approach, when crew selects flaps one, "A" sys. hyd. pressure drops for a second to 500psi and below. Both "A" sys. low pressure lights come on and of course the hyd. annonciator. It seems to be happening only when the hydraulic quantity sometimes goes up a gallon too high on the indicator and then comes back down. All that happening in flight. It never happens on climb when gears are selected up and engines are at higher power settings.
Now, here's what I tried.
All hyd. filters have been replaced, including the hyd. res. air system.
Hyd. press. module relief valve (thinking it was dumping pressure)
Hyd. res. air pressure regulator (twice)
I know somebody's probably seen this problem before but it's a first for me. I would appreciate some input.
Puzzled