servicing the hydraulics fluids

[cessnadriver]

Hello ALL.
Here's my next Skymaster question. This is mostly for the C337 mechanics but owner's can chime in. My old '65 c337 needs the hyd. fluid replaced, and yes I did check the maintenance manual. The manual is some-what vague. Short of using a Hyd. mule (Hyd test set), Is there a way to drain ALL of the hydraulic fluid out of the system and then replenish it? I want to remove the old fluid because it's probably been in there since the aircraft was new. The fluid is yellow instead of bright red. If possible I'd like to do this WITHOUT CYCLING of the gear. At the present time I have no wings or tail booms installed!
Thanks as always,
BILLS bstory@pa.rr.com

[Skymaster337B]

Just open up the nose gear actuator return line, and the reservoir will drain out. Caution: make sure you have a jack supporting the nose incase the nose gear actuator's mechanical lock fails.

As for the fluid in the rest of the lines you'll have to run the gear to purge it out.

[cessnadriver]

Okay, Thanks. I'll try that. And yes I'll be using jacks for the acft. Don't want the thing on it's belly.
BILLS