used to see the canisters blow out carbon pebbles and cover the fender thats why i decided to change the filters
wouldnt that suggest that you are getting pressure from some source blowing into the canister? like a fuel line from the selector valve connected to the wrong place filling the canister with fuel
My canister has a vacuum line and a vent line , but nothing that would cause fuel to fill the canister or pressurize it
The "filter" is a fresh air inlet filter to prevent dust from being drawn into the canister by engine vacuum. The activated carbon granules contained inside the canister passively absorb fuel vapors that evaporate from the fuel tank(s) and the carburetor fuel bowl and then gradually migrate into the EVAP canister through a physical process of partial pressure equilibrium. While the engine is running, fresh air drawn through the canister filter and across the carbon granules only partially purges the fuel vapor that collects in the canister. A trace amount of fuel vapor remains permanently bound to the carbon granules. Eventually, the carbon granules saturate with fuel and the canister loses its effectiveness. This is normal over the useful life of the canister.
Rarely, a canister purge valve diaphragm perforates, exposing the tank and carburetor vent lines directly to engine vacuum. In such cases raw fuel can be drawn into the canister resulting in immediate saturation with fuel dripping from the canister. In this situation the canister is rendered instantly useless.
In either scenario, the heat necessary to totally drive fuel from carbon granules and restore the effectiveness of a canister would destroy the canister - not-to-mention the extreme hazard of heating the fuel in the first place. The only solutions are canister replacement or elimination. The consequence of elimination is noxious fuel odor, especially on warm days.
Carbon granules leaking from an EVAP canister can be a problem caused by failed internal baffles/screens or liquid fuel floating the carbon granules out through the vent lines.