Windscreen Washers

Details

Written by Malcolm Eades

Problem

The car's original system was vacuum operated and made ingenious use of manifold vacuum to pump water to the nozzles on the scuttle. Regrettably the system can be vulnerable to leaks in the air chamber and relies on high vacuum (i.e. throttle nearly closed) for full effectiveness. This makes it less effective with sustained use at high speeds (e.g. motorway conditions). Replacement original parts are disproportionately expensive. An effective washer system is an MOT requirement.

Solution

Fit an electric pump with a separate switch on or under the dash.

Method

Halfords and similar retailers sell a good range of windscreen washer gear or you may spot a good system in a scrap yard.  The pump will require a power feed via the switch. This can be mounted either in the original hole where the vacuum switch fitted, or, if you prefer to leave this in place, albeit inactive, I suggest a small panel fitted below the dash, convenient to whichever hand you prefer. Make it fall naturally to the outstretched hand or the danger is that you will look down for it and lose sight of the road ahead.

Power can be taken from the A4 terminal on the fuse unit and fed back through the bulkhead. Alternatively you could find a convenient single bullet connector under the dash and substitute a double so that the extra wire can be added. Make sure you choose one that is controlled by the ignition switch. The extra load is small and fleeting so there should not be any overload implications.

You need to select a switch that is spring loaded so that contact is made only while pressure is maintained on it. Toggle switches are available but look unsatisfactory against burr walnut. The starter switch is the right type so if you have a spare, it can be suitably mounted. You could use a spare "W" knob from the wiper switch or devise another symbol that can be cut into an old knob from which the original letter is removed with fine emery cloth

The small electric pump needs mounting discreetly to avoid too long a length of single wire outside the loom (avoid garish plastic colours if possible). Check whether polarity is an issue to avoid wiring it back to front. The water pipe to the pump is easily fitted to the existing output union on the lid of the bottle (but consider the bottle's location if you are planning to fit a brake servo - see "Brakes"). The output from the pump is connected to the nozzle feed pipe which runs behind the dash and up to the T-piece between the nozzles.. Originally rubber tubing was fitted and this looks best. Black plastic would be more practical and longer-lasting but translucent pipe generally looks very out-of-place in a fifties engine bay.

If practicality is more important than looks, and you do a high mileage, you may consider fitting a bigger capacity water container from another car. A browse round a scrap-yard can often reveal the very thing, complete with bracket, for little outlay.

The redundant vacuum union on the manifold needs plugging with a short bolt or better still, use it to feed a brake servo or engine condition meter.