CHECKLIST - PREVENTIVE MAINTENANCE

Checklist For Preventive Maintenance Of In-use CNG Vehicles

This checklist is A GUIDE for preventive maintenance of fully built in-use CNG vehicles. Preventive maintenance shall be carried out by authorized installer at authorized workshop only, as prescribed in CMVR. Reference to relevant clauses of Safety Code of Practice, e.g. AIS 028, and guidelines issued by Central Government from time to time should be made wherever appropriate.

A. Details of CNG Vehicle
Name and address of owner of vehicle
Type of vehicle (LCWHCV) Model
Name of OE manufacturer Name of kit retrofitting agency
Name and address of bus body builder
Name and address of approved inspecting agency
Chassis No; Engine No. and Vehicle Registration No.
Year of manufacture of vehicle Date of endorsement of CNG kit in RCTC book

B. Details of CNG System
Checking of Cylinders as per DOE/ vehicle testing agency approvals	Approved Specification at the time of Type Approval	Remarks of Inspection Authority
No. of Cylinders
Approval from DOE
Validity of DOE Certificate		Check or Re-test cylinders as per Gas Cylinder Rules, 1981
Other checks Check for corrosion on any CNG components/ mountings of gas cylinders Ensure cylinder is securely mounted within the vehicle; check tightness of nuts and bolts Ensure minimum 5 mm clearance is kept between cylinders and vehicle body structure Distance between cylinder valve and bus body Quarterly extremities shall not be less than 200 mm.		Periodicity of checks Monthly Weekly Quarterly Quarterly
Cylinder Valves Approval from DOE Check for Shield / protection and physical damage to Valves Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action		Periodicity of checks Weekly Daily
Refilling Valve Check for dust cap / plug Check that engine should not start when dust cap/ plug is removed or open Check leakage for non-return valve using Methane Leak Detector and then use non- corrosive foaming agent on the identified points of leakage for confirmation and corrective action.		Periodicity of checks Weekly Weekly Daily
Fuel Line Check for corrosion on CNG fuel line Ensure fuel line is securely mounted Check U & pigtail bends Check hose for twists, kinks and damage or abrasions to the cover, which expose the wire/ fiber and shall be condemned on detection of any one of these defects. During servicing hose shall be replaced by new hose; after removal from vehicle Check distance between fuel line and exhaust heat source is more than 75 mm. Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action.		Periodicity of checks Monthly Weekly Monthly Weekly Weekly Weekly Daily
Shut Off Valve (Solenoid Valve(s)) wherever separately provided Ensure shut off valve is securely mounted Check operation for "Close & Open" as required and replace if found damaged Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action.		Periodicity of checks Weekly Weekly Daily
Regulator Ensure regulator is securely mounted Check for shield or protection Replace regulator diaphragms, hot water hoses, seals in accordance with manufacturer's recommendation> Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action.		Periodicity of checks Weekly Weekly Weekly Daily
Gas-Air Mixer Ensure gas-air mixer is securely mounted Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action.		Periodicity of checks Weekly Daily
Electrical wiring Ensure that current limiting device (fuse) is fitted as per manufacturer's specs and make Check any loose or open or broken wiring harness in engine compartment, under chassis and driver's cabin and take corrective action. Cable harness has to be as recommended/ approved by the OE vehicle manufacturers/retrofitters Battery terminal has to have a positive locking Check operation of battery cut-off switch as per manufacturer's recommendations Check for proper tight fitness and clamping of terminal fitting. Replace high tension cables as per manufacturer's recommendation.		Periodicity of checks Weekly Monthly Monthly Monthly Monthly Monthly
Service shut-off valve Check operation, replace in case inoperative Ensure service shut off valve is securely mounted Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action.		Periodicity of checks Weekly Weekly Daily
CNG Filter Ensure CNG filter is securely mounted -Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action		Periodicity of checks Weekly Daily
CNG Pressure Gauge Ensure CNG pressure indicator is securely mounted Check for operation, replace if it is inoperative Leak Test Using Methane Leak Detector and then use non-corrosive foaming agent on the identified points of leakage for confirmation and corrective action.		Periodicity of checks Weekly Weekly Daily