Volkswagen Golf Service & Repair Manual: 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 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). |
| – |
Read indicated measured value. |
| Normally (see notes), the vacuum that is generated should be
between 600 and 950 mbar (depending on engine size). |
| If the measured value is not reached even through the
preconditions (see notes) have been met, the vacuum system must
first be checked for leaks. |
| – |
For comparison purposes, generate the vacuum with the manual
vacuum pump -VAS 6213-
→ Chapter. |
| Open cut-off valve -B- to
facilitate removal of hose connections and adapter. |
|
|
|
Special tools and workshop equipment
required
Vacuum gauge for brake servo -VAS 6721-
...
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 ...
Other materials:
Notes on safety
Safety precautions during a road test using test
and measuring equipment
Risk of injuries due to unsecured test and measuring equipment
If a front passenger airbag is triggered during an accident,
insufficiently secured test and measuring equipment can becom ...
Changing bulbs in the tail light cluster in the tailgate
Fig. 237 In the tailgate: removing the
cover
Fig. 238 In the tailgate: removing the
bulb holder
First read and observe the introductory information
and safety warnings
The actions should only be carried out in the specified order:
1.
Obser ...
Air conditioner service and recycling equipment
At present, various manufacturers offer air conditioner
service devices on the market for evacuating, cleaning and
charging refrigerant in vehicle air conditioning systems.
...
© 2016-2026 Copyright www.vwgolf.org
Connecting vacuum gauge for brake servo -VAS 6721-
Checking for leaks