Objective Remove In-Tank Solenoid Valve Inspect Fuel Tank for Liquid Contamination Evaluate Replacement Valve Condition Install In-Tank Solenoid Valve and Leak Check Align New Solenoid Valve and Connect Fuel Lines Reposition Seal Boot Plate Why This Module is Important Every year the Natural Gas Civic gains popularity, and the number of units in operation increases. In order to keep repair costs reasonable, American Honda has decided to replace just the fuel tank internal solenoid valve, instead of the entire fuel tank assembly. Solenoid valve replacement, while not difficult, is a very precise process and requires hands-on practice. Before performing solenoid valve replacement on a customer vehicle, you must complete this training module. Getting Started 1. See your instructor for your assigned vehicle. 2. Throughout the module, a box designates the required activities. 3. Gather all of the items listed in the section. 4. Work on one Skill Objective at a time. 5. Fill in ALL blanks as you complete each Skill Objective. 6. Move to the next Skill Objective after you have completed the current Objective. Module Overview In this module, you will remove and replace the in-tank solenoid valve on a fuel tank assembly that has already been removed from the vehicle. This process will require visual inspection of the fuel tank, electrical testing of the replacement valve, leak checking of the newly installed valve, repositioning the fuel tank properly, and purging the tank prior to final reassembly. STOP Decision Point If you feel you can demonstrate the skills as outlined in the Module Objectives, see your instructor for on-the-job skills validation. This may require hands-on demonstrations for your instructor. Otherwise, proceed with the module. page 1 of 13
Skill Objective 1: Remove In-Tank Solenoid Valve Long breaker bar 2.5 inch socket 3/4-1 inch adapter Wrenches: 5/8 open, 11/16 line, 3/4 open, 13/16 line Needle nose pliers 3/8 inch drive ratchet and 8 mm socket One 18 inch zip tie 1. Place the tank/frame assembly on rubber lift blocks provided by your instructor. Position one block under each corner of the frame. 2. Wrap an 18 inch zip tie around the fuel tank frame and fuel lines as shown in the photo. Tighten the zip tie until it is snug - this will support both joint block and fuel lines when the lines are removed from the intank solenoid valve. NOTE: Before tank/frame disassembly, the joint block should be level with the shop floor. It is very important that the joint block remain level with the shop floor during and after solenoid valve replacement to ensure proper fuel line-to-valve alignment. 3. Release the sub harness clip from its seal boot backing plate tab. 4. Loosen the large seal boot clamp and pull clamp and boot aside far enough to disconnect the 2-pin connector from the in-tank solenoid valve harness pigtail. 5. Fold vent boot back to access fuel lines. page 2 of 13
NOTE: A bungee cord can be used to hold the seal boot away from the valve and fuel lines. Don't stretch the cord too tight or you may bend the lines. 6. Loosen and remove the three fuel line nuts from the connector fittings. Support the line connector with a wrench while loosening the line nut. 7. Release solenoid valve pigtail harness from the backing plate clip. 8. Pull all fuel pipes back slightly so that you can remove the line connectors. Be careful not to bend fuel lines- they will not realign properly if bent. 9. Remove the three fuel line connectors and discard all O-rings. 10. Position the 2.5 inch socket over valve and pigtail harness. Coil the pigtail on top of the solenoid valve. 11. Using a long breaker bar, loosen the valve. 12. Remove valve by hand and discard the original O-ring. 13. Hand the removed valve to your instructor Remove and discard page 3 of 13
Skill Objective 2: Inspect Fuel Tank for Liquid Contamination NOTE: The Civic Natural Gas in-tank solenoid valve is an electromechanical device that can fail for several reasons. The two main causes for failure are electrical opens or shorts, and fuel contamination. Just like their gasoline counterparts, natural gas vehicles are susceptible to fuel contamination. Natural gas contamination is typically in the form of moisture, which may condense into liquid inside the fuel tank. The primary component affected by fuel contamination is the in-tank solenoid valve. The solenoid valve may corrode or stick when subjected to liquid contamination. Honda special tool: fuel tank stand Shallow drain pan Tall Express Service lift blocks (4) 1. Remove the nut from the end of the Fuel Tank Stand. 2. From the solenoid valve end of the fuel tank, slide the Fuel Tank Stand through both tank band loops. 3. Reinstall the nut on the end of the Fuel Tank Stand. 4. Place a pan next to the fuel tank, about 3 inches away from the tank frame rail on the solenoid opening end. 5. With the help of another technician, tilt the fuel tank so that the solenoid opening is facing downward. As you tilt the fuel tank, be sure that the lift blocks do not shift and that the pan will end up directly beneath the solenoid opening - this will allow you to catch any liquid contaminants from the tank. Let the tank stand for at least 1 minute to let liquids run to the solenoid opening. Is there liquid contamination present in your fuel tank? Yes No If contamination is present, let the fuel tank stand for 5 minutes after all liquid has drained. If no contamination is present, go on to the next step. NOTE: The fuel tank draining times listed above are for training center practice only. Refer to the solenoid valve replacement Service Bulletin for official draining times. 6. With the help of another technician, lower the fuel tank back down so that all four corners of the tank frame are resting on the rubber lift blocks. 7. Remove the nut from the end of the Fuel Tank Stand, and remove the tool from your tank assembly. page 4 of 13
Skill Objective 3: Evaluate Replacement Valve Condition DVOM kit Solenoid test/energizing harness Replacement solenoid valve Battery or jumper box 1. Ask your instructor for a replacement solenoid valve. 2. Visually inspect the valve that will be installed for damage to thread area, 0-ring seat area, and wiring, and note your result below. Solenoid valve physical condition: Undamaged Damaged 3. Test resistance value of solenoid valve, compare to specification, and record below. Solenoid valve measured resistance (Specification 18-21 ohms). 4. Connect the solenoid test/energizing harness to the valve and an automobile battery or jumper box. Be sure the valve plunger moves when electrically activated - there is a small port on the valve body that you can look through. Based on your two electrical tests, does the solenoid valve pass or fail? Pass Fail STOP Check Point Do not proceed until you have consulted with your instructor. Instructor s initials: page 5 of 13
Skill Objective 4: Install In-Tank Solenoid Valve and Leak Check INSTALLATION Molykote 55 O-ring grease (no substitutes) 3/4 inch drive torque wrench 2.5 inch socket 3/4-1 inch adapter 1. Lubricate new O-ring with Molykote 55 grease and install on replacement valve. 2. Hand thread valve into tank making sure that O-ring seats properly in its grove. 3. Position 2.5 inch socket over valve, with pigtail harness coiled on end of valve. 4. Set torque wrench to 250 lb-ft and torque valve. LEAK CHECK Large nitrogen bottle with at least 1500 psi pressure Pressure regulator Braided hose with adapter fitting Snoop Liquid Leak Detector 3/8 inch drive torque wrench and 13/16 inch socket Large adjustable wrench page 6 of 13
5. Install blue leak check adapter fitting in solenoid valves receptacle port and torque to 20 in-lb. 6. Install the nitrogen gas regulator on the gas cylinder. 7. Connect high pressure hose to solenoid valve adapter and gas regulator. 8. Thread regulator key into regulator body 2-3 turns. DO NOT TURN KEY MORE THAN 3 TURNS YET. 9. Open the nitrogen cylinder valve. NOTE: For training purposes only, you will be pressurizing the fuel tank to 5% of nominal pressure (180 psi) during leak check. In the dealership, you will ALWAYS pressurize the fuel tank to 10% of nominal pressure (360 psi) during leak check. 10. Turn regulator key clockwise to set regulator to 250 psi initially and decrease, pressure as hissing sound decreases. This will increase the initial flow rate, speeding up the pressurization process. Pressurize fuel tank to 180 psi - DO NOT EXCEED 180 PSI. When the hissing stops, the tank is fully pressurized. 11. Apply Snoop Liquid Leak Detector to base of solenoid valve. Check for bubbles around O-ring seal. If no bubbles are present, continue to the next step. If bubbles are present, notify your instructor. STOP Check Point Do not proceed until you have consulted with your instructor. Instructor s initials: 12. Close the cylinder valve, remove key, and loosen the hose fitting at the fuel tank adapter to bleed off pressure. 13. Remove high pressure hose and adapter fitting from the solenoid valve. 14. Install the three fuel line connectors in the solenoid valve using new O-rings, and torque to specification. Do not place O-rings in the face of the connectors yet. NOTE: The PRO and main fuel line connectors are different in length. Be sure to install them in the correct ports. (The shorter connector is for the PRO port) Fuel Line PRD page 7 of 13
Skill Objective 5: Align New Solenoid Valve and Connect Fuel Lines 17 mm combination wrench (2) 3/8 inch drive ratchet and 17 mm socket Vernier caliper Masking tape Paint marking pen Wrenches: 5/8 open crowfoot 11/16 line crowfoot 3/4 open crowfoot (or socket) 13/16 line crowfoot 1. Place a piece of masking tape on each tank band near the spring/bolt assembly. 2. Measure the fuel tank band tension spring length with a vernier caliper. 3. Record the spring length values on the pieces of tape (see illustration below). These values will be used during reassembly. The two spring lengths may be different, so be sure to measure and record them individually. Measure from spring retainer to spring base 4. Loosen jam nuts and remove fuel tank band springs/bolts. page 8 of 13
5. With the help of another technician, carefully rotate the tank as needed until the fuel pipe flanges align perfectly with the line connector face. With the line nut held back, push the fuel line up to the connector face and rotate the tank until the two surfaces are parallel. The thread starting position on each solenoid valve will be different, so you MUST adjust the tank position precisely to avoid damaged O-rings and leaks. NOTE: The fuel tank may be stuck to the rubber cushions on the tension bands. Rock or lift the tank slightly to free it. Proper alignment This fitting can be assembled. Improper alignment This fitting cannot be assembled! Rotate tank clockwise to fix. 6. Ensure that the vertical lines on the tank remain aligned with bands. Adjust the tank laterally if needed, being sure that it does not rotate. 7. Install new O-rings on the face of all fuel pipe connectors, carefully connect fuel lines and torque to specification. 8. Reinstall both tank band tension spring/bolt assemblies and tighten spring bolts until spring length equals your previous measurements. 9. Install and tighten jam nuts to proper torque - 28 lb-ft. STOP Check Point Do not proceed until you have consulted with your instructor. Instructor s initials: page 9 of 13
Horizontal line - remove these Vertical line - save these NOTE: The fuel tank will be rotated into a different position once a new valve is installed and the fuel lines are properly aligned. The vertical paint lines on the tank are the best tool to ensure lateral alignment remains unchanged as the tank is repositioned. When re-marking the horizontal lines on the fuel tank, draw them to match the remaining horizontal lines on the tank bands. If significant rotation of the tank was necessary, you may need to remark the vertical portion as well. Be sure that you end up with four cross-shaped marks that look like what is shown on the left. 10. Remove horizontal paint lines from the tank only (not from the bands), using 3M adhesive remover or contact/brake cleaner. Use solvents sparingly to avoid damaging fuel tank paint. 11. Re-mark tank horizontal lines with supplied yellow paint marker. Trace over the original lines that remain on the tank bands and paint lines about 1.5 to 2 inches long on the tank. It is important to mark accurate lines, as these new lines will be used to evaluate proper tank position at the next fuel tank/line. The lines you paint may go over the label, but this is not a concern. page 10 of 13
Skill Objective 6: Reposition Seal Boot Plate Solenoid test/energizing harness Automobile battery or jumper box Spanner tool: Honda special tool #07WAA-S1G0100 3/8 inch drive breaker bar or ratchet 3/8 inch drive torque wrench 8 mm socket 1. Using the spanner tool, loosen the seal boot backing plate collar and rotate the backing plate to its original position. Use solenoid valve sub harness clip as a guide to positioning backing plate, rotate plate until sub harness clip lines up with tab. NOTE: Rotate the backing plate in the opposite direction that the tank was rotated. With the seal boot held near its normal position, adjust the backing plate until you can insert the harness clip. When the plate is in an acceptable position, the solenoid valve sub harness clip will engage easily. Be careful not to stretch the harness during this process. 2. Tighten the collar to 57 lb-ft. Be sure the backing plate stays in position - it will tend to move as you torque the collar. page 11 of 13
3. Clip the sub harness to its backing plate tab. 4. Clip the 2-pin solenoid valve pigtail to its tab on backing plate. 5. Close the manual shut-off valve mounted on the fuel tank frame. 6. Connect the solenoid test/energizing harness to the solenoid valve 2-pin connector, and an automobile battery or jumper box. This will electrically activate the solenoid valve to purge nitrogen from the fuel tank. 7. Slowly open the manual valve to start purging the fuel tank. The purging process may take 10-15 minutes. NOTE: The solenoid valve will not fully open without some back pressure in the fuel line initially. With the manual valve closed, some pressure is created in the fuel line when the solenoid valve is electrically activated. Once the solenoid opens fully, you can regulate the flow of gas using the manual valve. 8. Disconnect the solenoid test/energizing harness and reconnect the 2-pin sub harness connector to the solenoid valve connector. 9. Reassemble the seal boot completely and tighten the large clamp. 10. Remove zip tie from the tank/frame assembly. page 12 of 13
STOP Evaluation Before having your instructor sign your session map, be prepared to: Describe the function of the Fuel Tank Stand. Describe the necessary tests performed on new solenoid valves prior to installation. Describe the process used to align fuel line flanges. Describe the tools, equipment and pressure used to perform and leak check on the solenoid valve. Instructor s initials: SUMMARY When working on any natural gas vehicle, systems knowledge, safe work practices and proper tools are essential. Replacing a fuel tank solenoid valve requires a higher level of attention to detail than most other Civic Natural Gas repairs. If a fuel line O-ring is installed incorrectly, a relatively small leak can occur, but if the fuel tank solenoid valve O-ring is installed incorrectly, the entire contents of the fuel tank may be discharged. Performing each step of the solenoid replacement procedure carefully and in order, will not only save time, but will also prevent fuel leakage. page 13 of 13