Windows washer water pump mounting

[col320ce]

Should the windows washer water pump be mounted vertically or horizontally.  Mine is vertical and works when it's primed but if I try to use it the following day it doesn't seem to move the water as the 'gears' are spining in air.
I assume this is a positional thing.
Any pictures of it in a RHD 230SL as I'm not sure where it goes if it's horizontal.
Thanks for any help...

[cfm65@me.com]

Hi Col,
The washer pump is mounted horizontally.
If you look under the General Discussion section, about 3 posts down is a post re Hemmels restorations. They have a nice picture of the engine bay of a LHD which should give you an idea. Mine is unfortunately also LH. However, someone is bound to send you a picture if you cant figure it out.
Regards
Chris

[Tyler S]

Either way it is mounted, air can get into the system if the washer bottle level is lower than the pump. A check valve can be added to the end of the washer hose in the bottle to keep it primed.

[Garry]

This is mine on a ’65 230SL RHD

Garry

[col320ce]

Awesome info!
I'll re mount mine and try to source a check valve.

[col320ce]

All mounted horizontally and working well.  I've ordered a 4mm  check valve so hopefully this makes it work instantly each time...
Thanks as always...