Honda Civic Service Manual: Fuel Filter B Element Removal and Installation (R18A9)

1.

Raise the vehicle on a lift, and make sure it is securely supported.

This procedure should be done outside in a well-ventilated area or in a properly equipped CNG shop.

This procedure will allow you to safely work on any part of the fuel system downstream of the manual shut-off valve, such as fuel pressure regulator P1 or the fuel injectors.

1.

Close the manual shut-off valve (A).

2.

Start the engine, and let it idle.

3.

After a few minutes, the engine will stall.

4.

Turn the ignition switch to LOCK (0).

1.

Remove the engine undercover (A).

1.

Remove the fuel filter B housing (A), and replace the fuel filter B element (B).

1.

Apply silicone grease (Shinetsu silicone GR 10M) to a new O-ring (A) and carefully install it into its proper position.

2.

Install the fuel filter B element (B) and the fuel filter B housing (C).

NOTE: If the fuel filter B housing is rusty or damaged, replace the housing and its seal (D).

1.

Install the engine undercover (A).

1.

Open the manual shut-off valve (A).

Check for a gas leak if there is an odor coming from the vehicle. Compressed natural gas (CNG) can only be smelled, not seen.

1.

Open the hood and the fuel fill door.

2.

Connect a vacuum pump/gauge, 0－30 inHg, to the hose (A) from fuel pressure regulator P1, and apply 67.7 kPa (20.0 inHg, 508 mmHg) of vacuum.

3.

If fuel pressure regulator P2 does not hold vacuum, replace it before continuing to the next step.

4.

Inspect the fuel lines and hoses under the hood for kinks, abrasion, and other signs of damage.

5.

With the manual shut-off valve open, turn the ignition switch to ON (II), but do not start the engine.

6.

After the fuel pressure regulator shut-off solenoid valve/fuel tank internal solenoid valve operates for about 2 seconds, the fuel pressure in the fuel lines rises.

7.

Turn the ignition switch to LOCK (0).

8.

Repeat this two or three times.

9.

Within 1 minute, check for any damaged lines with a leak detector (A) (Snap-on Combustible Gas Leak Detector or Snoop Liquid Leak Detector (B)).

10.

If no damage was noticed during the inspection, turn the ignition switch to ON (II) for 2 seconds, then turn the ignition switch to LOCK (0).

11.

Within 1 minute, check for a leak at the vent hose outlet inside the fuel pipe protector (A).

12.

If you detect a leak, remove the vent hose, and check the fuel lines and fittings at the in-tank solenoid valve and the join block with a leak detector.

13.

If you cannot find the leak, raise the vehicle on a lift, remove the under-floor cover.

14.

Inspect all the fuel lines under the vehicle, visually, and with a leak detector.

15.

If you still cannot find the leak, remove the rear seat, then check all fuel lines and fittings at the fuel tank and the fuel joint block.