Charcoal Canister Rebuild (1 Viewer)

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Aug 28, 2020
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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.

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OSS

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That's an impressive amount of work.
Debbie Downer left her comments below:

The charcoal canister is an emmisions component of the EVAP system. It's purpose is to reduce the evaporation of gasoline vapors into the atmosphere. In doing so, it also has the added benefit of reducing gasoline odors when the vehicle is parked.
Modifying any component of the emissions system is illegal if the vehicle is still required to take smog tests. Any modification is considered tampering and grounds for failing a test.
While repairing a charcoal canister is commendable handiwork, it technically won't pass a smog test and if no smog test is required, a charcoal canister isn't even necessary (except to freshen up the air in a closed garage).
 
Joined
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Is it legal to use a non-stock charcoal canister? We're in a tight spot considering you can't buy them from Toyota anymore.

At any rate, I'm still getting pressure in my tank. Frustrating. I'm going to keep digging to see what's going on.
 

diesellibrarian

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I thought that was maybe it so I put a new OEM cap on at the same time I rebuilt the canister.

Good call. Might be worth pulling the hoses off the manifold that the fuel lines pass through to get to the separator in the rear passenger fender. The line that runs to the evap tank passes through that manifold. On my truck, the tube was rusted and completely clogged. I've since replaced the manifold, but as a temporary fix I ran a longer fuel line straight from the top of the separator to the evap line that runs to the front, and that solved the pressurization problem. I'll see if I can find a diagram.
 
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diesellibrarian

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This is the manifold (red circle):
Fuel Tube Connector.PNG


The vertical piece of fuel line connects to the fuel tube connector on the inside of the fender, and then comes out the bottom tube on the connector. That's the one that was rusted and clogged on my 62. You can access this part from under the truck, near the fuel tank. Might be worth pulling off the hose, just to see what kind of shape the tube is in.
 
Joined
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This is the manifold (red circle): View attachment 2448961

The vertical piece of fuel line connects to the fuel tube connector on the inside of the fender, and then comes out the bottom tube on the connector. That's the one that was rusted and clogged on my 62. You can access this part from under the truck, near the fuel tank. Might be worth pulling off the hose, just to see what kind of shape the tube is in.

Very helpful! Thank you. The line feels restricted and this just might be it. I'll do this when I pull the tank to put in the fuel pump for the EFI I'm installing....
 

OSS

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I bet it's still the check valve in the canister creating the pressure in the tank. A little pressure is normal. A big whoosh is bad.
To rule out if it's the check valve or not, just vent the Tank hose to atmosphere for a day. If the tank doesn't pressurize when the charcoal canister is taken out of the equation- the culprit is that damn check valve
 

Spike Strip

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The 'Check Valve' in the CC is just steel ball and a spring; it gets badly corroded and there isn't much, if anything, you can do to get it to function properly.

I haven't done this yet, but I was thinking of drilling that valve out and installing a 'One-Way' check valve at a low psi (1 hg) in-line just before the canister. This is essentially how toyota did it in the 40 series to vent the tank under the passenger seat.

What size is that hose? Anyone remember ?

Amazon product
 
Joined
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Boulder, CO
I bet it's still the check valve in the canister creating the pressure in the tank. A little pressure is normal. A big whoosh is bad.
To rule out if it's the check valve or not, just vent the Tank hose to atmosphere for a day. If the tank doesn't pressurize when the charcoal canister is taken out of the equation- the culprit is that damn check valve

That's a good test. I'm thinking about it and I really don't see any harm in removing the check valve, so I think that could be an option.
 
Joined
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Is it legal to use a non-stock charcoal canister? We're in a tight spot considering you can't buy them from Toyota anymore.

At any rate, I'm still getting pressure in my tank. Frustrating. I'm going to keep digging to see what's going on.

I do in CA and we're pretty strict
 

John Staton

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want a cheap fix....here you go.
 

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