Gas system - check leaktightness

AP47.00-W-4752A

Gas system - check leaktightness

25.11.09



Checking

 Danger!

Risk of explosion caused by escaping natural gas or overheated compressed-gas tanks when working on natural gas powered vehicles. Risk of frostbite to parts of the body caused by escaping natural gas and by touching components near the valves when emptying compressed-gas tanks. Risk of poisoning or risk of suffocation caused by inhaling natural gas.

Remove any sources of ignition.

Ensure that the work area is adequately ventilated.

Wear heat protective gloves.

AS00.00-Z-0018-01A



Notes on work safety regulations for vehicles with natural gas-powered engines

AH00.10-N-1000-04A



The check should only be performed on vehicles with completely full compressed-gas tanks

Danger!

Risk of accident caused by vehicle starting off by itself when engine is running. Risk of injury caused by contusions and burns during starting procedure or when working near the engine as it is running

Secure vehicle to prevent it from moving by itself.
Wear closed and snug-fitting work clothes.
Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

1

Start engine, allow to run at idle speed for a short time and then switch off engine

 Push the suction hose onto the exhaust pipe.

2

Open front flap

 Danger!

Risk of injury caused by body parts being pinched or crushed as cab is tilted

Ensure that no one is within the tilting range of the cab as it is being tilted. Always tilt the cab all the way to the end position and secure with the safety strut.

AS60.80-Z-0001-01A

3

Tilt cab



Notes on tilting the cab

AH60.80-N-0003-01A

4

Check all high-pressure components: compressed-gas tank (5), fuses/pressure retainers on compressed-gas tank (5.1), shutoff valves with fuse (6), screw plugs (7), cross threaded connections (8), check valve (9), T-threaded connection (11), gas pressure sensor (B109), high-pressure gas lines (12), high pressure gas filter (13) and gas pressure regulator (4) for leaktightness

 Cover components and gas line connections with foaming agent e.g. soapy water or commercially available leak detection spray and check whether bubbles are formed. If leaks are detected, seal or replace the component or gas line connection concerned

- subject to separate repair order.

5

Check all low-pressure components for leaks: gas pipe connections at charge air manifold fitting (1), gas-filled pipe (2) and gas-filled hose (3)

 Cover components and gas line connections with foaming agent e.g. soapy water or commercially available leak detection spray and check whether bubbles are formed. If leaks are detected, seal or replace the component or gas line connection concerned

- subject to separate repair order.

6

Remove cover from charge air manifold, and check gas temperature sensor (B107) and gas pressure sensor (B108) for leaks

 Cover components with foaming agent e.g. soapy water or commercially available leak detection spray and check whether bubbles are formed. If leaks are detected, seal or replace the component concerned

- subject to separate repair order.

7

Remove cylinder head cover



Remove/install cylinder head cover

AR01.20-W-5014H

8

Check gas injection valves (Y86.1 to Y86.6) for leaks

 Cover components with foaming agent e.g. soapy water or commercially available leak detection spray and check whether bubbles are formed. If leaks are detected, seal or replace the component concerned

- subject to separate repair order.

9

Install cylinder head cover



Remove/install cylinder head cover

AR01.20-W-5014H

10

Check threaded connections, gas pipe between check valve (9) and filling connection (10) for leaks

 To perform the check, the vehicle must first be briefly topped up with natural gas and wetted with foaming agent e.g. soapy water or commercially available leak detection spray. Check threaded connections and gas pipes for leaks. If leaks are detected, seal or replace the component concerned

- subject to separate repair order.

11

Record the results in the compressed gas tank test log

 The compressed-gas tank test log is enclosed with the test logbook supplied with the vehicle.