Oil from breather pipe

[svenedin]

Hi, I have recently purchased a 1969 minor saloon and am experiencing oil leak from rear crankcase seal. I have been cleaning/ replacing breathing items to improve this but nothing is working. Have read about the PCV valve and would like to try this next but unsure where I need to fit it. I have 1098 engine. Could anyone advise or send photos to help, and where would AI get one from?
Gazsen

It depends what breather system you are currently running. Your 1969 car may have used the PCV valve system originally but engines get changed so it is hard to say. Can you post photos of your engine bay so we can see what you have?

Stephen

[Classiccars]

I had the same issue and my cannister pipe goes to air.I took advice from the great forum sorters and moggie owners.So removed rad and timing cover and its many bolts put in order on cardboard so you know they go back the same way.Quite awkward.I put two of the metal wool cleaners as advised inside after removing the spring clip.New correct gasket in place as thete are two shapes and put it all back on.So far no more oil.A guy at a car show advised it is a known fault.I had to clean the cannister out as it was gunned up with muck and metal shards.

[mowogg]

The above description is probably a 1275 engine with the canister on the timing cover.

Regarding your car, does it have a canister on thr tappet covers? If so has it been cleaned out and where is it connected?

I have this on mine which I have connected via a Pcv valve to thr inlet manifold

[svenedin]

The above description is probably a 1275 engine with the canister on the timing cover.

Regarding your car, does it have a canister on thr tappet covers? If so has it been cleaned out and where is it connected?

I have this on mine which I have connected via a Pcv valve to thr inlet manifold

That is what I have on a 1098 but the canister is on a tappet chest cover. It works very well providing the canister is not completely blocked with crud and all the hoses are in good condition with no leaks.

Stephen

[gazsen]

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Hi,
sorry for the late reply, still trying to get used to using this forum. I have attached one photo. Think it shows everything!
Appreciate your help with this.
Gary

[svenedin]

20230729_113633.jpg
Hi,
sorry for the late reply, still trying to get used to using this forum. I have attached one photo. Think it shows everything!
Appreciate your help with this.
Gary

You have an identical set-up to my 1969 car. I notice you have a non-standard fuel pump incidentally.

There are quite a few reasons why this type of breather system can fail:

1) The oil separator can contains some wire wool. This can rust and clog up the breather system completely. To clean this, remove the tappet chest cover and breather hose and clean out the can. You may have to fish out rusty contents with some bent wire. Wash the can with carburettor cleaner or petrol. Then re-pack the can with a stainless steel pot scourer but do not pack it too tight.

2) The PCV valve contains a rubber diaphragm. To access this slide off the metal clip and remove the top plate of the PCV valve. Examine the rubber diaphragm for signs of splits, holes or of hardening (it should be flexible). Replace the diaphragm if damaged.

3) The small air hole in the top plate of the PCV valve can become blocked.

4) The poppet valve in the base of the valve can become blocked with oil sludge.

5) Air leaks from deteriorated breather hose, loose clips or a failed tappet chest gasket (check both). Replace as necessary but be sure to use reinforced breather hose which can tolerate hot oily fumes. Use the later neoprene tappet chest gasket for this later engine.

6) The oil filler cap should be the longer vented type (this contains a wire wool filter).

Stephen

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IMG_9256.jpeg (3.39 MiB) Viewed 1154 times

[svenedin]

By the way, the top plate of the PCV valve has a tendency to go rusty. If you don’t like that you can de-rust and give the top plate a coat of spray acrylic clear coat. Ensure the small air hole in the top plate is clear. Sometimes the poppet valve inside the valve at the base can become clogged. You can clear this by removing the PCV valve from the engine and cleaning it out with carburettor cleaner. The poppet valve at the base is not removable. Only the top plate is steel, the rest is aluminium alloy.

When you remove the top plate you should find a diaphragm, metal diaphragm pressure plate and a spring.

To confuse matters, there are 2 designs of this Smiths PCV valve an early and a late. The early type has a diaphragm that is no longer available. Parts are aviable for the later type. If your PCV valve is original to your 1969 car it is the later type.

Stephen

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[gazsen]

Hi,
To answer your points:
1. Removed and cleaned. Didn`t seem very dirty and no signs of rust so replaced as is.
2. Didn`t realise this was the PCV valve. Handbook says emission valve. Anyway, took this apart and cleaned everything. Diaphragm is flexible rubber with small hole in. Waiting for stock from ESM to order.
3. Hole is clear.
4. Cleaned all of these parts.
5. Replaced breather hoses either side of PCV with hose supplied by ESM. Replaced tappet housing gasket with cork type. Will look for neoprene replacement. Have slight oil leak from here now.
6. Replaced with new vented type.

Regards, Gary

[svenedin]

Hi,
To answer your points:
1. Removed and cleaned. Didn`t seem very dirty and no signs of rust so replaced as is.
2. Didn`t realise this was the PCV valve. Handbook says emission valve. Anyway, took this apart and cleaned everything. Diaphragm is flexible rubber with small hole in. Waiting for stock from ESM to order.
3. Hole is clear.
4. Cleaned all of these parts.
5. Replaced breather hoses either side of PCV with hose supplied by ESM. Replaced tappet housing gasket with cork type. Will look for neoprene replacement. Have slight oil leak from here now.
6. Replaced with new vented type.

Regards, Gary

Seems like you've done a very thorough job. The diaphragm was also used on some early Minis and is available from here:https://www.somerfordmini.co.uk/diaphragm-pcv-valve

The tappet chest gasket: https://www.somerfordmini.co.uk/gasket- ... ver-rubber

Remember to replace the rubber washer under the cup washer on the tappet cover. https://www.somerfordmini.co.uk/seal-co ... cover-bolt

Don't be tempted to over tighten the tappet covers or they will leak. Just ensure the mating surfaces are clean.

Stephen

[gazsen]

Thanks for your advice.
Was wondering if the seal on the crankshaft was replaceable relatively easily?
Regards, Gary

[svenedin]

Thanks for your advice.
Was wondering if the seal on the crankshaft was replaceable relatively easily?
Regards, Gary

See this current thread: viewtopic.php?t=76715

[philthehill]

Just to add to the above:-
There is no seal lip or otherwise fitted to the crankshaft of a 803cc, 948cc, 1098cc or 1275cc 'A' Series in line engine.

[gazsen]

Hi,
Thanks for this info. Am also looking at changing to -ve earth and have read online a method of doing this. Any advice you can poffer?
Regards, Gary