Munich - Drivers tend to buy new windscreen wiper blades on an average of every two years. So are the present blades still delivering reliable service, or is a new purchase needed to ensure good visibility? A careful look at wiper blades is advisable now before winter sets in. TÜV SÜD has practical tips.
Wipers that appear to be performing poorly need not always be replaced straight away. Sometimes careful cleaning can work wonders. A household nailbrush is excellent for this purpose – be sure to brush across, not along, the rubber strip. The blades are easiest to clean when removed from the wipers; a solution of normal washing-up liquid or car shampoo is generally enough to give good results. Stubborn dirt can usually be removed using undiluted anti-freeze windscreen washer additive on a piece of kitchen towel. However, avoid solvents like thinners or benzene, which are unsuitable because they destroy the thin graphite compound film which coats high-quality wiper blades – and may not stop there. The rubber of the blades itself also suffers from the wrong cleaning methods and may even be rendered permanently unusable.
Incidentally, smears do not necessarily indicate a problem with the wiper blades, but may be the fault of the windscreen itself. Wax or silicone residues, perhaps from car washes, can be removed with glass-cleaner or special cleaning cloths. However, it is too late for these solutions if the windscreen has been damaged by stone chippings or scratches; replacement of the whole windscreen, or at least repair – for which sophisticated and effective procedures are now available – may be necessary
Changing: The TÜV SÜD professionals generally advise that annual replacement is a good rule of thumb for conventional windscreen wipers, and recommend selecting well-known brands. Although the price may be higher, the longer life and improved performance of the blades usually makes up for it.
Although many manufacturers emphasise that their wiper blades are of natural rubber, synthetic rubber is by no means a bad choice for windscreen wiper systems. The best product is a dual-compound wiper, with the top section of the blade made of synthetic rubber and the blade next to the windscreen of natural rubber; these wipers are also less susceptible to summer heat.
Upgrading: Today's cars are often fitted with flat blades, or armless wipers, as standard features. These wipers exert a more even pressure on the windscreen and thus clean the glass more effectively, particularly at higher speeds. This new system can be retrofitted to many older cars. Although flat blades are more expensive than conventional wipers, they also have a longer service life – up to two years according to TÜV SÜD's experience – so that drivers end up recouping at least part of the extra cost.
Arms: If new wiper blades and cleaning the windscreen on both sides fail to restore visibility, the wiper arms themselves may be at fault. When a new high-quality wiper blade rattles, its contact angle to the windscreen is probably incorrect. This is often the result of manipulation or even vandalism of the wiper arm. Repair workshops can measure the 'offset angle' using special measuring gauges and correct the setting if necessary.
Rear window: Rear windscreen wipers are often overlooked as being ‘out of sight, out of mind’, and are frequently treated carelessly when drivers are clearing ice from their windscreens. If the rubber edges of old wiper blades tear at a later stage, this may go unnoticed until visibility is impaired during the next journey in the rain. The main concern in this situation is that metal parts of the wiper blade may be exposed and scratch the windscreen.
Treatment: All drivers can play a major part in extending the useful life of their car's windscreen wipers. Using windscreen wipers to remove light coatings of ice from the windscreen is not only unsuccessful; after only a few sweeps, the sharp crystals in the ice layer will actually destroy the wiper edge, which is only a few hundredths of a millimetre thick. And leaves and conifer needles are not much kinder to windscreen wipers; once they end up under the blades, the only solution is to stop and remove them by hand.