Testing cooling system pressure cap - RA20001044300X(20-4300)
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Operation no. of operation texts and work units or standard texts and flat rates:
PRESSURE CAP WITH DETENT
| Cap (5) | turn anti-clockwise as far as detent 1 to release pressure. Do not open cap (5) unless coolant temperature is below 90 °C. Risk of scalding! |
| Test cap (3) 124 589 00 91 00 | attach to tester (2) 124 589 24 21 00, take off. |
| Double connection (4) 124 589 53 63 00 | attach to tester (2) 124 589 24 21 00, take off. |
| Cap (5) | attach to double connection (4), take off. |
| Opening pressure of pressure relief valve | test. See table for opening pressure. |
| Vacuum valve | test. Raise vacuum valve (6) for this step.
NOTE:
The vacuum valve (4) must be resting against the rubber seal (5) of the sealing plate, it must be possible to raise it easily and it must spring back when released. The base for the sealing plate on the expansion tank must be flat. Replace pressure cap if corroded. The part no. and the pressure cap code number are stamped in the cap. |
2-STAGE PRESSURE CAP IN MODEL 210
| Cap (5a) | turn half a revolution anti-clockwise to release pressure. Do not open cap (5a) unless coolant temperature is below 90 °C. Risk of scalding! |
| Adapter (3a) 210 589 03 63 00 | attach to tester (2) 124 589 24 21 00, take off. |
| 2-stage cap (5a) | screw onto adapter (3a), unscrew; pay attention to note. |
| Opening pressure of pressure relief valve | test; see table for opening pressure.
NOTE:
The cap code numbers are stamped in the cap. See note for design of 2-stage cap.
|
TEST DATA OF CAP WITH DETENT
| Cap code number | Pressure relief valve opens at bar gauge | Vacuum valve opens at bar vacuum | |
| when new | used | ||
| 140 | 1.4 ± 0.1 | 1.4 -0.1 | 0.1 |
TEST DATA OF 2-STAGE CAP
| Cap code number | Pressure relief valve opens at bar gauge | Vacuum valve opens at bar vacuum | |
| 1st stage | 2nd stage | ||
| 140/200 | 1.4 ± 0.1 | 2.0 ± 0.1 | 0.1 |
Special tools
NOTE:
A 2-stage cap is installed in model 210.
The 2-stage cap must be screwed in far enough until the lug engages in the notch on the coolant expansion reservoir.
The cap has an additional pressure stage so that the system pressure is able to rise by up to 2 bar in the engine off heating phase without the coolant flowing out.