Volkswagen Fox 2004 Workshop Manual page 104

Fox 2004 ➤
3 - Cyl. diesel engine - Edition 02.2009
– Unscrew pressure regulating valve -2- and close valves -3-
and -4-.
– Connect test connection -5- to fuel supply union of tandem
pump using a commercially available compressed air connec‐
tion and a section of fuel hose. Use a spring-type clamp to
secure.
Note
To turn the pressure regulating valve -2- the knob must be pulled
upwards.
– Connect compressed air hose -1- (compressed air source) to
tester unit -V.A.G 1687- .
Note
If there is water in the sight glass, drain at water drain screw -6-.
– Open valve -3-.
– Adjust pressure to 1.0 bar with pressure regulating valve -2-.
Caution
The maximum test pressure lies by 1.3 bar and this must not
be exceed.
– Open valve -4- and wait until the test circuit is filled. If neces‐
sary readjust pressure to 1.0 bar.
– Close valve -3- to retain pressure and observe the pressure
drop over a period of 1 minute.
If the pressure does not drop the tandem pump can be reused, if
the pressure drops the tandem pump must be renewed.
100
Rep. Gr.20 - Supply system - Fuel tank, fuel pump