Gas system - check leaktightness

AP47.00-D-4752LG

Gas system - check leaktightness

15.04.2016

Engine

271.951 in model 906

with code MY9 (Liquefied Gas Technology (LGT))

1

Filling valve

2

Valve unit

3

Gas cylinder

4

Solenoid valve with filter

5

Evaporator pressure regulator

6

In-line filter

7

Gas rail

8

Pressure sensor

9

Temperature sensor

10

Gas injection valves

A

High-pressure circuit 30 bar

B

Low-pressure circuit 2.5 bar

 Danger !

Risk of explosion due to escaping combustible gas or overheating of gas cylinders.Risk of injury caused by burns to skin and eyes. Risk of frostbite to body parts caused by escaping gas and by touching components near the valves when emptying gas cylinders. Risk of poisoning or suffocation caused by inhaling gas.

Remove any sources of ignition.
Protective clothing, safety gloves and safety glasses must always be worn.
Ensure that the work area is adequately ventilated.
When working on vehicles at ambient temperatures over 60 °C, all gas cylinders must be removed.

AS00.00-Z-0018-01A

 Danger !

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

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

AS00.00-Z-0005-01A



Check

1

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

 Check should only be performed on vehicles with completely filled gas reservoir.

2

Remove cover from valve unit (2)

3

All high-pressure components: Check filling valve (1), gas reservoir (3), valve unit (2) on liquid gas tank (3), gas shutoff valve on valve unit (2), solenoid valve with filter (4), evaporator pressure regulator (5), gas pressure line, gas pressure hose, screw plugs, cross unions and T-threaded connections for leaktightness

 Cover components and gas line connections all-round with foaming agent, e.g. soapy water or commercially available leak detection spray and check for bubbles. If leak is found, seal or replace component or gas line connection subject to separate repair order.

4

All low-pressure components: Check in-line filter (6), gas pressure line, temperature sensor (9), pressure sensor (8) gas pressure hose, screw plugs, cross unions and T-threaded connections for leaktightness

 Cover components and gas line connections all-round with foaming agent, e.g. soapy water or commercially available leak detection spray and check for bubbles. If leak is found, seal or replace component or gas line connection subject to separate repair order.

5

Remove covering from gas rail (7)

6

Check gas injection valves (10) for leaktightness

 Cover components with foaming agent e.g. soapy water or commercially available leak detection spray and check whether bubbles are formed. If leak found, seal or replace component subject to separate repair order.

7

Fit covering onto gas rail (7)

8

Check filling valve (1) for leaktightness

 To check it, the vehicle has to be filled temporarily with liquefied petroleum gas and covered with foaming agent, e.g. soapy water or commercially available leak detection spray. Check threaded connections and gas pipes connections for leaks. If leak found, seal or replace component subject to separate repair order.

9

Install cover onto valve unit (2)

10

Document test result in gas reservoir test log

 The gas reservoir test log is available as an attachment to the vehicle's inspection logbook.