VW Golf manuals

Volkswagen Golf Service & Repair Manual: Checking for leaks

  Note
The average air pressure of the earth's atmosphere at sea level is 1013 mbar and decreases steeply as the altitude increases (approx. 100 mbar/1,000 m altitude). Local and time fluctuations also influence vacuum generation.
A cold engine, a switched-on air-conditioning system as well as engine idling have an adverse influence on generation of a vacuum.
–  Before starting work, check all vacuum hoses for damage (e.g. cracks or marten bite) and to check that they are correctly and firmly attached
–  Connect brake servo vacuum gauge -VAS 6721- → Chapter.
–  Open cut-off valve -A-.
   
–  Close cut-off valves -B+C-.
–  Start warm engine (>60°C), press accelerator briefly (engine speed above 2,000 rpm).
Normally (see notes), the vacuum that is generated should be between 600 and 950 mbar (depending on engine size).
 

Checking for leaks

–  Open cut-off valve -C- to evacuate brake servo.
–  Switch off engine.
–  Read and make a note of measured value shown.
A vacuum decrease of 400 mbar in 12 hours is permissible.
If the vacuum decrease is greater, check for leaks in the vicinity of ...
1 -  Brake servo
or
2 -  Non-return valve of vacuum hoses with connectors and vacuum pump/suction pipe.
.
If there are large leaks, the vacuum decreases steeply within a few seconds.
Vacuum check in vicinity of brake servo:
 

Checking for leaks

–  After generation of vacuum, close cut-off valve -A- to check brake servo vacuum system.
Vacuum check in vicinity of non-return valve, vacuum hoses with connectors and vacuum pump or intake manifold:
 

Checking for leaks

–  Once vacuum has been generated, close shut-off valve -C- to check vacuum system from brake servo vacuum gauge -VAS 6721- to intake manifold or to vacuum pump.
Open cut-off valve -B- to facilitate removal of hose connections and adapter.
 

Checking for leaks

Checking vacuum generation
  Note The average air pressure of the earth's atmosphere at sea level is 1013 mbar and decreases steeply as the altitude increases (approx. 100 mb ...

Vacuum generation with manual vacuum pump -VAS 6213-
In certain cases, vacuum can be generated with the manual vacuum pump -VAS 6213- instead of with the engine or the vacuum pump. –  ...

Other materials:

Renewing bulb for glove compartment light -W6-
  Note If an LED glove compartment light -W6- is faulty, the entire light must be renewed. Removing –  Remove glove compartment light -W6- → Chapter.     ...

Driving with an open tailgate
First read and observe the introductory information and safety warnings Driving with an open tailgate is particularly dangerous. Ensure that the open tailgate and any objects are secured properly, and take appropriate measures to reduce the quantity of toxic exhaust fumes entering the vehicl ...

Luggage compartment cover
Fig. 96 In the luggage compartment: removing and installing the luggage compartment cover First read and observe the introductory information and safety warnings When attached, the supporting straps will automatically raise or lower the luggage compartment cover when you open or close the ...

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