This post was a great guide that convinced me to try this rather than just replacing it with the ACDelco 215-153. I will follow up once I have more miles on it and can confirm that all is working.
A few weeks before doing the rebuild, I had used carb cleaner (B-12) to free up the check valves in the tank port. The check vales did free up and I could get some air to flow through that port but it was pretty minimal. It turned out to be not enough and I was still getting a 'whoooosh' when I pulled the gas cap after driving.
During the rebuild, I THINK I found what was restricting the flow in my canister. There is a tiny filter inside the tube that leads to the tank port. This is a very small filter area and I'm guessing it got pretty clogged up. I replaced it with some loose cotton gauze.
One thing to note on the tank port... When I apply compressed air at a high pressure the check valve closes. It seems that the design is such that the port is designed to close when the pressure it too high. I don't know why they would do this, but that's what happens. It could be just the effect of the check valve spring fully compressing and choking off the air pathway. When I apply moderate pressure the air flows freely through the tank port.
A few notes and photo:
- I used a grinder to grind off the upper lip. The cap then came off, but it did take a little tapping as it fits inside of the outer canister.
- I then removed the rest of the lip from the cap to make reassembly easier.
- I used carb cleaner again to clear out the check valves in the tank port. You should hear these click around when you apply compressed air.
- I used aquarium charcoal which was a little more coarse than the OEM charcoal, but I doubt that will be an issue.
- When reinstalling the paper filters, I clocked them so fresh filter material was exposed to the openings in the steel plate.
- I used some epoxy to seal the cap back on, but there's enough overlap to use a few self-tapping screws and a little RTV. That would be a better/rebuildable way to do it.
A few weeks before doing the rebuild, I had used carb cleaner (B-12) to free up the check valves in the tank port. The check vales did free up and I could get some air to flow through that port but it was pretty minimal. It turned out to be not enough and I was still getting a 'whoooosh' when I pulled the gas cap after driving.
During the rebuild, I THINK I found what was restricting the flow in my canister. There is a tiny filter inside the tube that leads to the tank port. This is a very small filter area and I'm guessing it got pretty clogged up. I replaced it with some loose cotton gauze.
One thing to note on the tank port... When I apply compressed air at a high pressure the check valve closes. It seems that the design is such that the port is designed to close when the pressure it too high. I don't know why they would do this, but that's what happens. It could be just the effect of the check valve spring fully compressing and choking off the air pathway. When I apply moderate pressure the air flows freely through the tank port.
A few notes and photo:
- I used a grinder to grind off the upper lip. The cap then came off, but it did take a little tapping as it fits inside of the outer canister.
- I then removed the rest of the lip from the cap to make reassembly easier.
- I used carb cleaner again to clear out the check valves in the tank port. You should hear these click around when you apply compressed air.
- I used aquarium charcoal which was a little more coarse than the OEM charcoal, but I doubt that will be an issue.
- When reinstalling the paper filters, I clocked them so fresh filter material was exposed to the openings in the steel plate.
- I used some epoxy to seal the cap back on, but there's enough overlap to use a few self-tapping screws and a little RTV. That would be a better/rebuildable way to do it.