Evap canister line
01-10-2020, 04:35 PM
#11
Yes you can use rubber. Best to use line rated for fuel systems.
p0442 is "small leak detected"
The leak is likely to be the cap, the purge valve, or vent valve. In 20 years I've never had to replace a canister on a GM truck for an evap leak and I work on them all the time for EVAP issues
If you get a new cap, get it from the dealership. Sometimes I find new caps on cars from autozone that still leak.
p0442 is "small leak detected"
The leak is likely to be the cap, the purge valve, or vent valve. In 20 years I've never had to replace a canister on a GM truck for an evap leak and I work on them all the time for EVAP issues
If you get a new cap, get it from the dealership. Sometimes I find new caps on cars from autozone that still leak.
01-10-2020, 11:48 PM
#12
TECH Fanatic
Thread Starter
Yes you can use rubber. Best to use line rated for fuel systems.
p0442 is "small leak detected"
The leak is likely to be the cap, the purge valve, or vent valve. In 20 years I've never had to replace a canister on a GM truck for an evap leak and I work on them all the time for EVAP issues
If you get a new cap, get it from the dealership. Sometimes I find new caps on cars from autozone that still leak.
p0442 is "small leak detected"
The leak is likely to be the cap, the purge valve, or vent valve. In 20 years I've never had to replace a canister on a GM truck for an evap leak and I work on them all the time for EVAP issues
If you get a new cap, get it from the dealership. Sometimes I find new caps on cars from autozone that still leak.
01-12-2020, 05:29 PM
#13
There's a canister, a purge valve (at the engine on the intake), a vent valve (under the truck near the fuel tank), the fuel tank itself, and a bunch of lines. Any of that can have a leak.
I need to do a video on how I do the vent valves. You have to cut the old hoses off and reuse/rebuild them. It's massive bullshit considering how perfect everything has to be to avoid leaks, that they make you hack up lines to reuse them.
Also there is a pressure sensor on the top of the fuel pump that fails and will give you leak codes, but it's usually a large leak code, not small leak code. When the pressure sensor fails it gets stuck, it doesn't leak, but for whatever reason during programming gm didn't pick up on that if the sensor gets stuck in one spot in can be the sensor itself, so you'll get leak codes instead because it thinks the system cannot seal off and get any vacuum or pressure in the tank.
I need to do a video on how I do the vent valves. You have to cut the old hoses off and reuse/rebuild them. It's massive bullshit considering how perfect everything has to be to avoid leaks, that they make you hack up lines to reuse them.
Also there is a pressure sensor on the top of the fuel pump that fails and will give you leak codes, but it's usually a large leak code, not small leak code. When the pressure sensor fails it gets stuck, it doesn't leak, but for whatever reason during programming gm didn't pick up on that if the sensor gets stuck in one spot in can be the sensor itself, so you'll get leak codes instead because it thinks the system cannot seal off and get any vacuum or pressure in the tank.
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