Hi,

This is a subject not many know about, but let me tell you , after 1 heater core, 2 radiators, 1 water pump and 1 cylinder head, my brother is wishing he new more about it.

The story started with the heater core letting go in a big way. A quick bypass on the road and he was mobile againg, bit not for long before the water pump let go. Boy what a saga, the water pump was renewed and happily back on the road when suddenly the radiator let go.

Now this is all getting a bit to much. A brand new radiator was fitted and would you believe it just 9 days later this new radiator let go with 15 pin prick holes in it.

If that wasn’t bad enough, the alloy cylinder head packed it in as well.

We’re talking serious dollars here and all because a new piece of electrical equipment wasn’t earthed properly.

You see if there is an earthing problem in your vehicle, electricity will somehow find a way out and it did it through the cooling system of my brothers Mazda Bravo.

This can be easily checked by placing the negative probe of a good multi meter on the negative terminal of the battery and placing the positive proble in the radiator neck submerged in the coolant (careful not to touch the metal radiator). The guage should register below 0.3 of a volt, my brothers was registering something like 4 volts.

He still has a problem, as it registers 0.51 of a volt which is still too high. A lot of questioning and I found out the radiator guy used a coolant you had to add water to, and you guessed it, he used just normal old tap water. This is one of the worst things you can do to a radiator, as normal tap water has too many chemicals in it and conducts electricity very easily, causing electrolysis.

Only use pre-mixed coolant or if you must use water, make sure it is DISTILLED and only DISTILLED.

So the next job for my brother is to drain the cooling system again and use the right stuff.

See you put there!

Driving Technique With a mental picture of your route, or better still, with markers in place, and all your vehicle preparation done, its time to start the crossing. Before you enter the water, remember to take off your seat belt and wind down your window. Using low range second gear at 1500-2000 rpm (for most 4x4's) creates just the right bow wave. Its important to get the speed just right as too fast will send water everywhere while too slow may flood the engine bay. Hopefully you follow your markers and get to the other side with no problems. But if you do strike problems avoid using the clutch as this may allow water to get between the friction plate and the flywheel, resulting in limited drive. If the wheels start to slip, its important not to over-rev the engine but back-off the accelerator and hope the wheels regain traction. Excessive wheel-spin will not help. If the engine stalls, put the vehicle in neutral without using the clutch and attempt to restart. If luck is on your side the engine will fire up. Now is not a good time to wish you had already disconnected the fan belt, as your engine bay will be flooded. Its normally best to use 1st gear low range and with a minimum of clutch usage, try and extricate yourself from this predicament.