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MG TD TF 1500 - How to reduce oil leakage

Have tried twice to install Moss seals to prevent oil leakage and it came out worse than with the old seals. However, the third time I first bonded in the front lip seal in the timing cover using a fixture to get it positioned exactly 90 degree to the shaft and left it overnight for the sealant to harden before installing the sump.

In the rear seal housing I made an extra drainage into the sump and surprice surprice, now after 20 km . driving it produced 7 drops in 19 min. Earlier one drop every four sec. If it doesn´t get worse I am prepared to live with that.


YS Strom

If it does get worse, consider fitting a PCV valve from an MGB. Its something that I am on with myself and has been reported on the forum by others several times before.
Dave H
Dave Hill

Here's a photo of my test set-up as it is at the moment.
I am running a restrictor 1.5mm to each side of the inlet manifold and so far so good. It does make a difference on my car.

Regards
Declan

Declan Burns

On my TF:
For the rear seal leak, I have installed one of the boxes that Gord Whatley sells. It uses two of the bolts to the bell housing for mounting and has a drain valve as well.
In four years of driving, 12,00 miles, I have never found anything present, when I opened the drain Valve. Curious!
JB Warwick

Times back I made a none return valve to be fitted to the vent pipe. It was meant to be used together with a pipe with a restrictor from the inlet manifold to the push rod cover. However, after having installed a supercharger I gave up this project. Used in engines without supercharger it might reduce oil leak.

See image

YS Strom

And here is my retrofit of an MGB type Smiths PCV which can be seen just to the rear of the air filer and below it. I have minimal oil leakage with this modification.



John Quilter (TD8986)

Here's the principle of my set-up. The PCV valve is difficult to source at a reasonable price.

Regards
Declan

Declan Burns

Spelling correction

Declan Burns

Is the clear plastic tube with the water just to measure the amount of vacuum in the crankcase?
John Quilter (TD8986)

Do it right the first time! Line bore the main bearing clearance to the minimum clearances of .001-.0015" and you will have virtually NO leaks! Perhaps a quarter size leak or less but only when stopped!
Len Fanelli
Abingdon Performance Llc.
Len Fanelli

Agree with Len.

Also, is the current leak from the rear or the front?

On the front, did you install the new full seal or stay with the original?

The full seals work well, but I cut a small V in the inner race so any oil that sits against the seal will drain back into the sump.

I also make sure my pan is as flat as I can get it and pay a lot of attention to getting the gasket on correctly. I use the cork seal and have very little leakage. My B GT leaks more.
Bruce Cunha

John,
That is correct-temporary just for the measurements. I measured -120mm water gauge at idle.

Regards
Declan
Declan Burns

If the side cover is vented with a 1" pipe and the rocker cover has 1/2 " tube connected to the low pressure side of the carb/air cleaner oil bath.... how could the case not be vented properly? Regards, tom
tm peterson

With the original seal or Moss seal both leaked a lot during driving and also after stop.

However, with the modified Moss seal there was by MG standard no leak after stop – 7 drops in 18 min. and 1 drop during 12 min. idling.

After an extended test drive I am planning - when I will check leak also during driving - I will produce new inf. on leaks and pics of modification if it has worked well.

Now to my question. As I understand it, a PCV will prevent leak during driving, but might make it leak "as usual" after stop. Is that correct?

After using a fixture to get the front lip seal bonded into the timing cover in 90 deg. to the crank and left for the sealant to harden before fitting the sump, it does not leak at all. I will produce a picture of that too in due course.
Y Strom

Tom,
On my system it is not connected to the low pressure side of the oil bath filter. It is connected to the inlet manifold tapped at both ends and a t-piece just under the PCV valve.
This PCV valve is actually a pressure regulating valve and not a non return valve as fitted to modern cars.
http://mgaguru.com/mgtech/engine/cv103.htm

Regards
Declan
Declan Burns

Declan, I still have the question..with all of the "holes" in the block, how can there be any pressure within the block to force oil out?
Regards, Tom
tm peterson

Tom,
Not sure what you mean by all the "holes" in the block.
All accessible sources of infiltration air are plugged-e.g. Oil filler cap, rocker cover vent and the side cover (I use a Wolseley 4/44 side cover which needs plugging). This in effect creates a closed loop system and crankcase vacuum. This in turn draws air in through the non-existent rear scroll seal. Where air flows in oil cannot flow out-at least in theory anyway.

Regards
Declan
Declan Burns

"Holes" in the block are a reference to all the normal vent sources that relieve any combustion chamber blow-by pressures in the block.
Regards, tom
tm peterson

Tom,
Then I think I have answered your question.
Regards
Declan
Declan Burns

This thread was discussed between 14/07/2017 and 19/07/2017

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