Preheat vacuum valve and Preheat Unit

[baliboy.schroeder]

Hi All,
I have covered this subject before, however...

I have cleaned my preheat vacuum valve , the brass screw cleaned and replaced and small internal ball bearing now moves. ( it was filthy and clogged)

  

The diaphragm in the Preheat unit appears intact.

Now, how do I test whether the two units actual works ?? Is there a way to test prior to putting everything back ?? 

And how far does the brass screw suppose to be turned ,there doesn`t appear to be any markings as a guide.

See Photos 

Your advice would be appreciated.

Regards
Klaus

[1500king]

Hi All,
I have covered this subject before, however...

I have cleaned my preheat vacuum valve , the brass screw cleaned and replaced and small internal ball bearing now moves. ( it was filthy and clogged)

  

The diaphragm in the Preheat unit appears intact.

Now, how do I test whether the two units actual works ?? Is there a way to test prior to putting everything back ?? 

And how far does the brass screw suppose to be turned ,there doesn`t appear to be any markings as a guide.

See Photos 

Your advice would be appreciated.

Regards
Klaus

Screw the brass screw in 9 full turns and so that it protrudes from where it screw into by 5.1mm. That is a good starting point.

The VW spec is a modulated air temp to carbs of 35-45c for that particular valve.