P20.00-2681-09
1 | High temperature cooling circuit cap | 5 | Expansion reservoir | |
2 | Expansion reservoir | 6a | High temperature cooling circuit tester cap | |
3 | Low-temperature circuit cap | 6b | Low temperature/high voltage cooling circuit tester cap | |
4 | High voltage cooling circuit cap | 7 | Pressure pump |
Danger | Risk of explosion caused by escaping hydrogen or overheating of the fuel tanks when working on the hydrogen system. Risk of frostbite to body parts caused by escaping gas and by touching component parts carrying gas when emptying fuel tanks. Risk of asphyxiation caused by inhalation of air diluted by hydrogen. Risk of burn injuries by coming into contact with an invisible pale blue hydrogen flame. | ||
Warning | Risk of injury to skin and eyes suffering scalding from contact with hot coolantspray. Risk of poisoning from swallowing coolant. | Do not open cooling system unless coolant temperature is below 90 °C. Open cap slowly and release the pressure. Do not pour coolant into beverage containers. | |
Topical note | Notes on fuel cell system | ||
Topical note | Notes on coolant level | ||
Topical note | Notes on fuel cell coolant | ||
Topical note | Notes on coolant | ||
| Remove | ||
1 | Ensure that the requirements for driving into the workshop are fulfilled. | ||
Topical note | Requirements for driving into the workshop | ||
2 | Print out "tank system, fuel cell, form event log," fill out, and attach to the vehicle somewhere clearly visible. | ||
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3 | Set heating to maximum heating output. | ||
4 | Remove engine compartment lining from center and front. | ||
5 | Remove underfloor paneling in the area of the coolant hoses and lines. | ||
Check (high temperature cooling circuit) | |||
6 | Unscrew high temperature cooling circuit cap (1) slowly from the expansion reservoir (2) and carefully relieve overpressure. | The cooling system of the fuel cell vehicle consists of three independent cooling circuits. | |
Do not mix the different kinds of coolant. | |||
The high temperature cooling circuit cap (1) for the fuel cell system has a yellow coloration. | |||
7 | Screw on high temperature cooling circuit tester cap (6a). | Adapter | |
8 | Connect pressure pump (7) to the high temperature cooling circuit tester cap (6a). | Adapter | |
Pressure pump | |||
9 | Apply test pressure to the high temperature cooling circuit for 2 minutes. | | |
There should be no pressure loss within a period of 2 minutes. | |||
Test pressure for pressure-testing the engine cooling system | |||
If pressure loss occurs, | |||
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Perform visual inspection of components carrying coolant. | |||
10 | Relive overpressure via the valve on the pressure pump (7). | Pressure pump | |
11 | Remove pressure pump (7) from the high temperature cooling circuit tester cap (6a). | Adapter | |
Pressure pump | |||
12 | Unscrew high temperature cooling circuit tester cap (6a). | Adapter | |
13 | Check coolant level of the coolant; correct if necessary. | ||
Check (low-temperature circuit) | |||
14 | Unscrew low-temperature circuit cap (3) slowly from the expansion reservoir (2) and carefully relieve overpressure. | The low-temperature circuit cap (3) has a black coloration. | |
15 | Screw on low temperature/high voltage cooling circuit tester cap (6b). | Test cap | |
16 | Connect pressure pump (7) to the low temperature/high voltage cooling circuit (6b) tester cap. | Pressure pump | |
Test cap | |||
17 | Apply test pressure to the low-temperature circuit for 2 minutes. | | |
There should be no pressure loss within a period of 2 minutes. | |||
Test pressure for pressure-testing the engine cooling system | |||
If pressure loss occurs, | |||
| |||
Perform visual inspection of components carrying coolant. | |||
18 | Relive overpressure via the valve on the pressure pump (7). | Pressure pump | |
19 | Remove pressure pump (7) from low temperature/high voltage cooling circuit tester cap (6b). | Pressure pump | |
Test cap | |||
20 | Unscrew low temperature/high voltage cooling circuit tester cap (6b). | Test cap | |
21 | Check coolant level and antifreeze content of the coolant; correct if necessary. | Coolant mixing ratio | |
Check (high voltage cooling circuit) | |||
22 | Unscrew high voltagecooling circuit cap (4) slowly from the expansion reservoir (5) and relieve overpressure carefully. | The high voltagecooling circuit cap (4) has a black coloration. | |
23 | Screw on low temperature/high voltage cooling circuit tester cap (6b). | Test cap | |
24 | Connect pressure pump (7) to the low temperature/high voltage cooling circuit (6b) tester cap. | Pressure pump | |
Test cap | |||
25 | Apply test pressure to high voltage cooling circuit for 2 minutes. | | |
There should be no pressure loss within a period of 2 minutes. | |||
Test pressure for pressure-testing the engine cooling system | |||
If pressure loss occurs, | |||
| |||
Perform visual inspection of components carrying coolant. | |||
26 | Relive overpressure via the valve on the pressure pump (7). | Pressure pump | |
27 | Remove pressure pump (7) from low temperature/high voltage cooling circuit tester cap (6b). | Pressure pump | |
Test cap | |||
28 | Unscrew low temperature/high voltage cooling circuit tester cap (6b). | Test cap | |
29 | Check coolant level and antifreeze content of the coolant; correct if necessary. | Coolant mixing ratio | |
| Install | ||
30 | Install underfloor paneling in the area of the coolant hoses and lines. | ||
31 | Install engine compartment lining at center and front. |
Check values for engine cooling system cap |
Number | Designation | Engine 780 in model 253.992/993 | Engine 780 in model 253.992/993 | ||
BE20.30-P-1005-03A | Test pressure for pressure-testing the engine cooling system | Overpressure | bar | 0,8 | 1,4 |
210 589 00 91 00
Test cap
253 589 03 91 00
Adapter
124 589 24 21 00
Pressure pump