PCV Valve guts

[David_Doan]

So I saw this intake on ebay that had the PCV valve attached and bought it for the PCV valve. In the pic it is not obvious that the guts are not there.



I thought I had remembered Moss having the rebuild kits, now they stock the the whole valve but not the kit. Anybody know where to get these parts? I Need 31-35 in this pic. 33 and 34 are the only ones I can find at the usual places. Moss has the whole unit for $60 - I should probably just order it. At least now i have the bracket and connections.

 

[dklawson]

That appears to be the early "thick flange" PCV valve and I have never seen parts for it. Like you, I bought a complete valve assembly (later thin flange type) so I would have a functional one on the Mini. At one time parts were available for the thin flange version.

Looking around the usual suppliers I use, I still find a valid part number for the later type diaphragm, 27H7758, but I do not find part numbers for the metal disk and spring that go with it. (This diaphragm will not fit the early thick flange PCV). It looks like The Roadster Factory still has a "reasonable" price for the complete later PCV assembly at $56 (part number 13H5191). There is also a NOS later PCV valve on eBay at the moment ( item 400446585192 ) for sale by Matthew's Parts (Buy it Now with shipping for $53).

 

[David_Doan]

Doug,

Thanks, I did not know there were 2 types. Moss has them for $60 as well. I'm guessing in this case a new one is better than NOS since the rubber in the NOS is probably hard by now.

 

[Jim_Gruber]

David, Not sure if you have rear seal leak issues or not. Don't we all at one time or another but putting a PCV on Bugsy's 1098 ended my problems with what I thought was the Exxon Valdez. Yes Bugsy still left a trail wherever he went but measured as 4-5 small drops from separate spots when he stopped not measured in quarts per minute.

 

[Boink]

I recall getting the rubber membrane off of eBay for about $3.

 

[dklawson]

The diaphragm you purchased for $3 is probably the later type which does not fit the thick flange PCV shown in the picture above. The later type diaphragms are basically simple disks with a specific profile. If I remember correctly, the early type are a rubber disk with a sort of pocket molded into one side to accept the sheet metal disk. It's a much more complicated design which explained to me why the later type was introduced fairly early and was used for more than a decade.

 

[Boink]

The diaphragm you purchased for $3 is probably the later type which does not fit the thick flange PCV shown in the picture above. The later type diaphragms are basically simple disks with a specific profile. If I remember correctly, the early type are a rubber disk with a sort of pocket molded into one side to accept the sheet metal disk. It's a much more complicated design which explained to me why the later type was introduced fairly early and was used for more than a decade.

By-golly I can't remember what mine was... though I recall the pocket thing. Mine looks exactly like yours. Somehow I thought they didn't make the pocket one anymore. Is it critical that part #34 (the piston thing) fits INTO part #35 (as opposed to just against it)? I used the simple membrane even though my original had the pocket-thing. It all seems centered anyway. :rapture:

 

[dklawson]

Is it critical that part #34 (the piston thing) fits INTO part #35 (as opposed to just against it)?

That's a good question. I guess it all depends on whether the valve seals when it is supposed to and opens when it is supposed to. I can't answer that.

 

[Boink]

I think I used the non-pocket type and it seemed to work. However, I'd occasionally pull some oil all the way to the intake manifold until I decided I had to dial down the vacuum just a bit (and when it was excessive one gets a LOT of smoke). Because the piston-thingy is spring-loaded, I figured I can use the newer, simpler, membrane. [But I could be all wet on this. :rapture: ]

EDIT: Upon further reflection, that pocket could be very important at times of serious vacuum (which may have been my situation). I don't see how the membrane would be adequately pulled down without holding on to the piston. Oil would then be possibly sucked right through the unit.