Breather Cap Questions? Whats inside?

[idrivemopar]

Just curious, i am cleaning out my breather cap for my 340, because i can only find chrome replacements, and i dont want chrome.

So, is there anythig besides the metal baffel inside the cap? Just want to make sure that once its clean, i can repaint it and use it. Anyone know if there is any filter material in there?

Here is what it looks like.

 

[copper67440]

Yes there is a "filter type media inside. It resembles a course steel wool. I bought one and got ready to paint it and upon cleaning it I tapped it on the bench and some nasty stuff came out and after looking closer wound up actually prying the bottom off very carefully and removed it all and replaced it with some course steel wool. I oiled it a little. Did it over a year ago and so far so good.

 

[Slantsixdan]

Originally the material was roving keratin fibre (i.e., hair) of one sort or another. Steel wool isn't a good choice because steel rusts and there will be condensation in the breather. Bronze wool is a much better choice. Use a medium-coarse grade of it and pull it apart so it's not densely packed. The idea is for it to trap liquid oil droplets but let air and vapor pass through, so you don't want it to be too restrictive but you also don't want big gaps in it.

 

[idrivemopar]

That would explain why i keep getting bits of stuff coming out. Thanks for the feedback, i think i will try and find a proper replacement one as there is not really any way to take it apart with out damaging it.

 

[Slantsixdan]

Replacement is easy if you don't mind it being shaped slightly different to the original. NAPA filter # 2997, Wix 42997, Standard BF28. Comes dichromate plated, not chromed; you can clean it with alcohol or brake cleaner and shoot it with black spray paint for an even closer to original appearance.

 

[copper67440]

I was able to carfeully pry the bottom off of mine i started with a small chisel and just worked it carfeully around the edge. It's only crimped not welded. It came apart easier than I thought. I never thought about bronze wool. I'll keep an eye on mine.

 

[Birdski]

I have a '73 RR with a 400 with the same original breather. I get some vapor chugging out the hose when disconnected from the air cleaner. Is this normal?

 

[Cranky]

Replacement is easy if you don't mind it being shaped slightly different to the original. NAPA filter # 2997, Wix 42997, Standard BF28. Comes dichromate plated, not chromed; you can clean it with alcohol or brake cleaner and shoot it with black spray paint for an even closer to original appearance.

25 bucks for that?? Dayam! And it's probably made in freakin China.....should be more like 3 bucks if that's the case.

 

[Cranky]

I have a '73 RR with a 400 with the same original breather. I get some vapor chugging out the hose when disconnected from the air cleaner. Is this normal?

Yup...but it depends on how much. If your engine is in good shape, then you'll have some due to blow by. It's impossible to get a perfect seal on the rings but if it's a lot, it could be a sign that your engine has excessive ring wear. Is it using any oil?

 

[Birdski]

Engine runs strong and doesn't use excessive oil and no smoke out the pipes. Oil pressure is good. Just thought it was odd the vapor actually chuggs some out of the disconnected breather. I thought it needed to be sucked in by the air cleaner and not blow out on its own. Could PCV valve condition affect this?

 

[Cranky]

The engine will always have crankcase pressure with some more than others depending on condition. Even an engine in excellent condition will have some but yes, engine vacuum through the PCV valve is supposed to help evacuate the crankcase. What year is your car?

 

[Birdski]

73 RR with a 400 with 22.5K original miles.

 

[Slantsixdan]

I thought it needed to be sucked in by the air cleaner and not blow out on its own. Could PCV valve condition affect this?

Yep, also condition of the PCV hose and the carburetor base passage (and on some applications the wrong carburetor base gasket can block off PCV vacuum). Also, the PCV valve must be the correct one. Many look alike, but the wrong one will give bad results.

I broke my (original) valve getting it out of the (original) grommet when I did the first-ever valve adjustment on my low-miles '73 shortly after I bought it. Rummaged around in the trunk, found a PCV valve in a Chrysler box, tossed it on, everything seemed fine. But not too long after that, I was trying to diagnose a weird idle problem. I took off the air cleaner lid and the idle changed dramatically. Nearly-new air filter was wet with oil, as was the inside of the air cleaner. And I could see smoke coming out of the air inlet fitting in the wall of the air cleaner. I was thinking the worst until I remembered having swapped that PCV valve. I went rummaging in the trunk again, found a known-correct new PCV valve, swapped it on, and the smoke disappeared. The replacement air filter is still in there with no oil on it. Ya gotta have the right PCV valve or the system won't work correctly! I prefer a genuine Chrysler valve, current P/N is 5175 351AA.