Breather (again)

[les]

I bought a manifold a while back, as a bonus it had a PCV attached. Whilst I have a standard system, ie canister to carb with closed rocker cover and appropriate cap. I wondered if this PCV installed between canister and inlet manifold would be the preferred option.
I’m trying to eliminate a small oil leak, probably from the scroll.

[svenedin]

This explains the two common setups.

https://www.morrisminor.org.uk/userfile ... nd-two.pdf

However there is a 3rd type which my car has. In this setup the rocker cover has no breather outlet and a breather type oil filler cap. It has a Type 2 breather chimney connected by a pipe not to the carb or air filter but to a special inlet manifold via a PCV valve. I will look for a picture but my car is away at the moment for a gearbox rebuild so it will be an old picture and probably not a good photo.

I would add that my car leaked oil from the rear crankshaft scroll seal but by replacing all the breather pipes, the breather oil filler; cleaning out the chimney (which was absolutely blocked with crud) and fitting a new PCV diaphragm the oil leak was cured. The chimney contained some rusty steel wool (like a Brillo pad) which I assume helps condense and catch oil. I replaced it with a stainless steel pot scourer or parts thereof.

So before changing your setup check all the pipes are clear and free of leaks in the breathing system and also the PCV diaphragm. That might be all you need.

IMG_7689.jpeg (2.87 MiB) Viewed 1174 times

[les]

I think you have the same system as I mentioned in my second sentence, and was wondering if this would be a better option than the system mentioned in the beginning of my post. I presume ‘chimney’ is what I referred to as a ‘canister’ ?
Just seen your picture, and yes that is what I am considering installing.

[svenedin]

I added to my post. Yes chimney or canister. I suggested checking that your breather system is free of blockages and working properly before changing anything.

[les]

Thanks for your replies.

[svenedin]

You're welcome. I believe there are advantages to the system that my car has. One of them is that oily fumes don't make a mess inside the throttle body of the carb because the fumes go into the inlet manifold instead.

[philthehill]

Les
Before you do anything check the diaphragm inside of the PCV valve. If it is vulcanised to the valve plate and there are any faults with the diaphragm you may as well chuck the valve as spares are not available for it and the diaphragms are not interchangeable.

[svenedin]

Les
Before you do anything check the diaphragm inside of the PCV valve. If it is vulcanised to the valve plate and there are any faults with the diaphragm you may as well chuck the valve as spares are not available for it and the diaphragms are not interchangeable.

It depends which PCV is fitted but the top plate/diaphragm is available from ESM

https://www.morrisminorspares.com/fuel- ... te-p830685

[philthehill]

The early PCV valve has the metal valve and diaphragm vulcanised together. The inside of the early valve body is different and does not have the 4 up-standings to locate and centralise the metal valve. The early diaphragm holds the metal valve central to the aperture leading to the inlet manifold.
Parts are available for the later PCV valve but not the early PCV valve.
Below is the inside of the early valve without the 4 up-standings which on the later PCV valve guides the metal valve.

PCV valve 1 (2) (1).JPG (779.16 KiB) Viewed 1138 times

Below is the vulcanised diaphragm and the metal plate is attached to the diaphragm by the vulcanised nodule's

PCV valve 2 (2).JPG (564.18 KiB) Viewed 1136 times

[les]

Looks like the valve I have is ok, it needs a good clean. The picture shows the diaphragm in poor order, unfortunately ESM are out of stock, I need to call them.

3A66C8BB-FE0F-4EC4-91B6-50600A6A9D08.jpeg (669.07 KiB) Viewed 1138 times

[philthehill]

Les
You have the later PCV valve for which spares are available but at the moment not from ESM. They are available from other suppliers.
https://www.ebay.co.uk/itm/284563103829 ... R-6Y7N6CYQ
Phil

[les]

Thanks Phil, I’ll have to shop around, I’ll call ESM though just to see if they will be stocking the item again. I would appreciate your view on fitting this valve being a better system than my canister to carb setup. I tend to think it would but open to opinion.

[svenedin]

Looks like the valve I have is ok, it needs a good clean. The picture shows the diaphragm in poor order, unfortunately ESM are out of stock, I need to call them.3A66C8BB-FE0F-4EC4-91B6-50600A6A9D08.jpeg

The diaphragm is in stock with ESM but not the complete refurbished PCV.

https://www.morrisminorspares.com/fuel- ... te-p830685

[philthehill]

The above link shows the top plate.
This is the diaphragm required for Les's PCV valve.
https://www.morrisminorspares.com/fuel- ... 58-p830604
The diaphragm in the above is out of stock at ESM.
That is why I posted an alternative supplier.

Les
Both breather systems have their pros and cons. Neither is perfect.
The later system from canister to carb is less maintenance, no diaphragm to fail.
The earlier system from canister to PCV valve is better in that I believe that the mixture is better controlled.
So, you take your pick. I think that I would not change the system already fitted if it is working well.
Make sure that the canister is not blocked.
Phil

[svenedin]

The above link shows the top plate.
This is the diaphragm required for Les's PCV valve.
https://www.morrisminorspares.com/fuel- ... 58-p830604
The diaphragm in the above is out of stock at ESM.
That is why I posted an alternative supplier.

Les
Both breather systems have their pros and cons. Neither is perfect.
The later system from canister to carb is less maintenance, no diaphragm to fail.
The earlier system from canister to PCV valve is better in that I believe that the mixture is better controlled.
So, you take your pick. I think that I would not change the system already fitted if it is working well.
Make sure that the canister is not blocked.
Phil

Ah yes of course. For some reason I thought the diaphragm came with the cap.

[les]

Thanks to you both I appreciate your comments. The canister is clean as gratefully modified by Phil pgp001.