'70 280sl power steering

I have a 280SL auto which I've owned for many years but have just put back on the road after storage for the last 2 years. It runs great but has very noisy powersteering (rumbles, creaks etc) under load when parking and it feels like you're teasing it around a bit at a time. Whats the best and worst case scenario and if it's just fluid levels remind me where it should go.

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steve e

[Arthur Dalton]

1- Check res. for full

2- Check filter in res.

3- Grease front end . 113 chassis have 12 fittings on front end. This is the old king pin set-up.

4- Check belt condition and tension.

PS - Res. is black 4" round container next to dist. w/ wing nut on top.