On-Board Refueling Vapor Recovery Function
On-Board Refueling Vapor Recovery, General Points
The law requires, that the refueling gases in the vehicle are collected (On-board Refueling Vapor Recovery). Fuel and refueling vapors must be separated in order to prevent fuel from flowing into the activated EVAP canister due to any inappropriate refueling or a defective nozzle.
Function Sequence for On-Board Refueling Vapor Recovery
Owing to its form, the filler neck functions as a suction jet pump. The fuel out from nozzle thus accelerates in the filler neck and the air around the nozzle is suctioned into the fuel tank. As a result of this air intake. The refueling vapor are not able to gather at the filler neck and are able to escape. The fuel vapors flow through The aeration/vent valves and aeration/vent lines to the activated EVAP canister, where they are stored. The fueling, pressure limiting valve and the vent valve also prevent any overfilling by closing off the aeration/vent line. Rollover valves are integrated at the top of the aeration/vent valves. If fuel gets into aeration/vent valves, they close off the aeration/vent lines to the activated EVAP canister, thus preventing fuel from flowing into the activated EVAP canister. The aeration/vent valves can also close briefly if there is sudden braking or acceleration, or when cornering.
- Put a "CAUTION: FLAMMABLE" sign in workshop.
- Never smoke while servicing fuel system. Keep open flames and sparks away from work area.
- Always furnish the workshop with a CO 2 fire extinguisher.
- Before removing fuel line parts, carry out the following procedures:
- Put drained fuel in an explosion-proof container and put lid on securely.
- Release fuel pressure from fuel line. Refer to Removal and Installation .
- Disconnect battery ground cable.
- Always replace O-ring when the fuel gauge retainer is removed.
- Never kink or twist hose and tube when they are installed.
- Never tighten hose and clamps excessively to avoid damaging hoses.
- After installation, run engine and check for fuel leaks at connections.
- Never attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.
Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire.