4 Repair
4.2.1. Performing a leak-down test
 3HAC022032-001  Revision: E112
© Copyright 2004-2008 ABB. All rights reserved.
4.2 General procedures
4.2.1. Performing a leak-down test 
General 
After refitting any motor and any gearbox, the integrity of all seals enclosing the gearbox oil 
must be tested. This is done in a leak-down test. 
Required equipment
Procedure 
Equipment, etc.  Art. no.  Note 
Leakdown tester   3HAC 0207-1   
Leak detection spray   -  
  Action  Note 
1. Finish the refitting procedure of the motor or gear in 
question. 
 
2. Remove the topmost oil plug on the gear in question, 
and replace it with the leakdown tester. 
Adapters may be required, which are included in the 
leakdown tester kit. 
Art. no. is specified above! 
3. Apply compressed air, and raise the pressure with the 
knob until the correct value is shown on the 
manometer. 
Recommended value: 
0.2 - 0.25 bar (20 - 25 kPa) 
4. Disconnect the compressed air supply.   
5. Wait for approx. 8-10 minutes. No pressure loss must 
be detected. 
If the compressed air is signifi-
cantly colder or warmer than the 
gearbox to be tested, a slight 
pressure increase or decrease 
respectively may occur. This is 
quite normal. 
6. Was any pressure drop evident? 
Localize the leak as detailed below. 
Remove the leakdown tester, and refit the oil plug.
The test is complete. 
 
7. Spray suspected leak areas with leak detection spray. 
Bubbles indicate a leak. 
8. When the leak has been localized: take the necessary 
measures to correct the leak.