by Laurent Castel
Due to my job, I’m a bit mad about reliability. For mathematics, reliability is the probability of success of a mission. For classic car tourer, it is your confidence level about your car.
You can find several publications about how to improve the drivability (engine power, lighting, indicators, brakes…), car comfort (waterproofness, seats, heater…). The purpose of my present writing is to gather tips and tricks that make an MG reliable. Descriptions of these improvements are often already described and I will just make a reference. A trusty car is a car that you can drive daily but also enjoy when you put the suitcase in for a peaceful journey.
First asset for a reliable car is simplicity. The MG TD is a good candidate.
However, our cars are old with a high mileage on the clock – severe drawback for reliability! We all know it is a common task for us to change the tyres, the brake linings, the bulbs, or the points; less considered is the wear out of electric or rubber parts.
So, I first recommend to check or change the fuel hoses, the brake hoses, the various suspension rubber bushings, the fan belt, the dynamo, and starter motor brushes. All these are cheap parts and could spoil your planned holiday if they fail.
Almost impossible to check for cracks or voltage insulation, cheap also, you should replace all the high tension leads around the distributor.
A bit more expensive is to fit a new water pump if you fear a sudden leak. And why not fit an improved six vane water pump? See TTT 2 N°32 p23 – tests from Geoffrey M. Baker show a 30% coolant flow improvement.
Ignition is one of the fear of mechanics. However, it is very reliable even, (or especially?) keeping with the original Kettering system.
Why fit a sports coil, commercial appellation for high voltage coil? Reliability is for tourers, not for racers. So, keep on with a good old low voltage one. It will generate enough voltage for any high compression engine with clean plugs up to 5500 RPM. And it will prevent accidental arcing on the leads, the distributor cap, or the rotor arm.
In a similar way, change the rotor arm for a high voltage one, with no rivet: they are often red. GRA2101HQ from Moss or Distributor doctor. This is called the strength stress principle. Reduced stress, increased strength: more reliable. Coil, or more precisely the cooling oil inside is more prone to self-arcing at high temperature. So, make sure the coil thermal flux is efficiently conducted to the firewall. It is mainly conduction cooled. Attach the coil to the firewall with a wide bracket. The coil itself is convection cooled by the inside coolant. So, it is better to attach the bracket to the highest part of the coil. See picture.
I even smear a layer of thermal compound between coil and bracket and between bracket and firewall. Sold on eBay for powerful microprocessors!
Whilst on the ignition system, many of us have experienced failures with new condensers. These devices are often very poorly manufactured by an unknown guy somewhere in the far east.
Nowadays, special capacitors (the electronic name for condensers) are available for high voltage pulse applications. These are common in power supplies of many domestic appliances. Recommendation is to fit one of these. Forget about car part manufacturers for condensers. Chose the best capacitor manufacturer for electronic designs: Vishay (space domain manufacturer): MKP1839 or MKP1845 series are designed for AC and pulse applications. This is exactly what we need. Refer to TTT 2 N° 31 p4. Eric Worpe describes how to adapt this part inside the distributor. Such a condenser is installed on two of my cars. 4000 Miles on them.
Electricity is often neglected by mechanics. A good wiring is the key to reliability. Splice is banned. Add a short ground wire to chassis for any current sink (headlights, horns, fuel pump). Insert shake proof washer on the terminal to penetrate the metal. See picture.
For hot wires (the ones carrying voltage) fit a rubber boot on the terminal. Many of us experienced the sudden engine stop due to the tacho gear box that rotates down to the distributor terminal. Fitting a rubber boot on it prevents a possible short circuit to ground.
See pictures.
Horns draw lots of current. It may damage your expensive Lucas push button on dashboard. Insert a relay. See TTT 2 N°30, p15 from myself.
In TTT 2 N°22 p16, Peter Cole explains how to protect the contacts of the original fuel pump by fitting a Transil*. This reduces the electric arcing across contacts and thus decreases wear out.
Install a redundant fuel pump as in aircraft! The inner design of the Lucas fuel pump allows to fit a secondary pump in series on the fuel pipe. A modern one can then be hidden just below the tank. A simple switch can activate the second pump without even stopping the car in case of failure of the Lucas one.
I have a Facet cube type pump which also allows fuel to freely flow in it when not powered. Don’t forget to test the redundant pump from time to time.
If you are about to remove the tank, a good thing is to coat it. It then is less prone to rust due to ethanol blends. It also copes with pin size holes and freezes all particles in it. You can get the resin material from several dealers. Restom, well known French manufacturer, makes its own kit including de-rust, cleaner and resin. A real best seller here. I’ve never heard any complaint about it.
Whilst at the tank, the sender unit is a well known leaky place. If it is leaking, replace the original cork gasket.
Ed’s note: The Octagon Car Club sells a gasket set (2 gaskets) in ethanol resistant rubber (you need to be a member to buy spares from the Club).
If it is not leaking, leave well alone (“if it ain’t broke, don’t fix it!”).
Many people claim to install an inline fuel filter after the pump. In case the filter is totally clogged there would be a risk of pump damage if it is installed before the pump. But in case the filter becomes totally clogged you would have certainly experienced problems before! The engine would stop well before the pump overheats. So, I personally recommend to install it before the pump. Just at the output of the tank. You don’t want any particle in your pump as well.
There is absolutely no risk for the pump if you check the filter regularly (once a year). They are transparent. Change it every 5000 Miles. It is really cheap.
About brakes. Leaky cylinders? Stuck piston? Change the fluid for silicon based fluid. This laborious job is described everywhere. It really is worth it. You will just forget about brake maintenance for at least a decade. Protect the bleed nipples with rubber caps. Sold on eBay for a few pounds. Do the same for grease Zerk.
And of course, don’t forget the regular maintenance as described in the workshop manual. Have your checklist ready at the beginning of the season. Many discussions on forums about checklists.
Your T-Type is now at the highest level of reliability (for a 70 year-old grandma). However, carry a minimum of spare parts. Just for peace of mind!
The Distributor Doctor (Martin Jay): https://www.distributordoctor.com
MG Octagon Car Club: http://www.mgoctagoncarclub.com/Parts/parts.html
Restom: https://www.restom.net/fr
*Note: Transils are available from the MG Octagon Car Club.