337D : Gear extension took "forever" out of Annual

[n86121]

The system is supposed to be self-'burping.'

While on the ground, cycle gear handle down.
That pressurizes and cycles everything.

Better to find an issue before takeoff, than after.

It should pop back to neutral down position within around 4 sec when warm out.
In winter maybe 6-8 secs

If it takes much longer, the system may be low, and/or there is probably air in the system.

Top off until it drools out the bottom of the drain under front engine,
Wash rinse repeat.

It can take a while to burp itself happy.

[B2C2]

I have found that for my mechanic, the hydraulic mule that they use for gear swing checks sucks hydraulic fluid out of the system when they shut it down. I always check that they have topped the fluid after they do this, as I had the same experience you did with slow gear action after annual when they first started doing this and check showed low fluid level. You said you topped the fluid, but I would check it again and perhaps drain and fill in case there is air trapped in the system somewhere.

[AV8ing]

FOLLOW UP:

First off, as Herb pointed out, this is a 1968 "D" Model, not '65 .

TRoubleshooting the problem on the ground - performed the hydraulic pump "isolation" test, ie. pumped gear doors open, then started just one engine, and low-and-behold, rear engine hydraulic pump is TU .

Anyone have spare pump the'de like to sell , otherwise who is the "go-to" shop for overhaul these days ?

Thanks!