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October 2009 a new lady joinedour house "a pretty 1948 MGTC". I  immediately began the process of getting to know her.One thing that the MG's do well when parked is leak a little oil. From my observations of ours & other TC's there are some common leak points, being:
 > Engine:
> Rear main
> Front main
> Side cover
> Oil pressure line outlet to head
> Oil pressure line to oil filter ( in my case we have a late TD pump &
> filter assembly fitted, no obvious leaks here)
> Tappet cover.
> Sump plug washer
> Gearbox:
> Drain plug washer
> Breather plug washer.
> Rear main.
> Differential, however my car is quite tight here, no leaks.
> Shock absorbers.

The engine front & rear mains require a little bit of work & there are some well documented solutions, my car isn't too bad, so I didn't need to explore this any further.The side & top tappet covers tend to leak a little, mine does but not  excessively, you can persevere with the cork gasket using aviation  compound & you can use a silastic adhesive. There are also nitrile  rubber or viton seal sets available. Oil pressure lines, this is where I have had the most success. The  original copper washers were well past their service life, copper  washers for oil pressure lines should never be re-used. I found  replacements provided by the MG parts suppliers to be unsuitable. So  I turned to the hydraulics industry & obtained Dowty washers. Dowty  washers (see photo) I believe are a British invention consisting of a  steel washer with a nitrile rubber or viton seal vulcanized to the  inner diameter, the seals are capable of withstanding high  temperatures & pressures, far greater than what the MGTC can subject  them to. Dowty washer are sized by their internal diameter or the  connection thread major diameter, though larger ID seals can be used  where large chamfers are found. After use all leaks dried up & my  engine oil pressure actually increased. Another issue concerns the engine side cover breather pipe, if yours  is touching the oil pressure fitting that feeds the head & pressure  gauge then it is likely you will get leak from that fitting, I have seen this on a number of cars & it caused by the pipe being fitted  upside down.> Engine sump plug washer, gearbox drain & breather plug washer leaks  were also eliminated using the dowty washers.Caution, the Dowty is designed to seal against two parallel
 surfaces, if you have a large chamfer then the Dowty may not seal.  Other solutions can be explored such as a a larger ID Dowty (take care  to centralize) or an o-ring & steel washer combination, I suggest you consult a hydraulic component supplier such as Pirtek if you have any concerns.

 The differential, as I said my car is quite tight, however some cars  develop leaks at the pinion shaft, Moss (Europe/USA) manufacture seal  flange kits that remedy this. Shock absorbers, apart from a stop gap solution such as oil seal  conditioners (rubber swelling agents) the only course is to rebuild  each unit. I have located a company in Mittagong who can fully  rebuild the TC units for around $150.00 each, I am advised this is  quite reasonable.
> Gearbox rear, I am yet tackle this.

 One other point of note are oils. Everyone including my cars previous  owner seems to have their own angle on the required oil type &  viscosity. I say when in doubt refer to the manual. However some  oils no longer exist & Australian conditions can demand a higher  viscosity, this is when you need the advice of an expert. I have  found the Penrite range to be excellent & their website is very good,  offering recommendations along with data sheets. The oils  recommended for the TC were spot on.
 If anyone has any queries please feel free to contact me.

 Craig Robinson


Craig can be contacted through the Web Master on



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