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LR200808 003

LR200808 003

Wiper Motor Restoration

When I started my restoration, the very first part I rejuvenated was one of the Lucas windscreen wiper motors. It’s quite fitting that the very last part to restore is the other wiper motor.

With this finished, the task moves from restoration to one of reassembly.
I thought I’d document my work and provide a comprehensive “how to” so others can use it as a guide, Plus the other half wanted to experiment with her new camera, so please find below….

Having removed the wiper motor from the vehicle, the first step is to use a craft knife to remove the rubber fixing gasket from the windscreen mounting.

With the rubber removed, use a flat bladed screwdriver to unscrew the two fixing nuts, then remove the mounting block. This can be cleaned up using a solvent like paraffin.

Using a small spanner, push the exposed spring down to give yourself easy access to the circlip that holds the wiper spindle in place. This can be removed by hand, but be careful that it doesn’t ping off and get lost.

With the clip removed the spindle can be removed from the back of the motor and the spring removed from the front. Clean all the parts and keep them to the side.

The front cover will be removed next, use a small BA spanner or socket to remove the three retaining nuts. The front cover will most likely be stuck fast, so you may need to use a craft knife to loosen the cork seal, but be careful not to cut through it as spares are unavailable and you’d need to spend ages cutting out a new one from a sheet of cork – way too fiddly a job to contemplate!

Once the cover is off, it’s very clear to see why the old motors can seem sluggish as most of the grease has turned to a thick mayonnaise due to water ingress. You can pick out the gears and mechanism then clean in paraffin or petrol. Beware of the small brass bushes that look like washers, you’ll want to ensure that you don’t loose them when you are cleaning things up!
You can use a toothbrush and cotton buds to get all the old grease from in-between the gaps of the base plate once the gears are removed.

With the mechanicals stripped out and cleaned, we can turn to the electrical side of things. Undo the two fixing at the back of the motor and withdraw the cover to reveal the motor. You need to be careful not to damage the motors +ve supply cable which sits on a rubber insulating plate.

Next, the motor’s brush assembly plate can be removed by unfastening the two nuts at either side of the coil. You’ll also need to disconnect the coil cable from the plate, just use a soldering iron to do this, then the plate should lift off easily. You can see the two carbon brushes in the last photo. We’ll renew these as part of the course.

The rotor can be removed now, then using a small BA spanner to remove the two nuts holding the stator in place. All items can be give a good clean with a solvent soaked rag.
Depending on the rotor condition, you may want to run some very fine emery paper around the commutator to clean and smooth out any imperfections.

At this stage you can clean / paint strip the motor housings and give the base plate a really good clean to get rid of the last of the gunk. A coat of matt black paint finished the steel front cover nicely, though to be 100% accurate, I think you’d want to paint it with crackle effect paint.

With the parts all cleaned, you can reassemble the motor. When fitting the stator you need to double check that the rotor will spin freely before tightening up the two nuts.

As a matter of course I replace the brushes, however the closest replacements were a little too large, so they were sanded down to fit. With new brushes in place the brush plate assembly is refitted to the rest of the motor. Finally the cables are soldered back in place and the cover refitted. I’ve renewed the earth cable within the motor as the old one was frayed and damaged.

That completes the electrical side, over to the mechanical side. The gears are resembled and packed with grease. I’ve used a red Teflon grease from Halfords which is designed for cycles. It’s waterproof and very satble so it won’t ‘weep’ out over time. The key is to really get the grease in as it will protect the motor against any water ingress.

Finally the painted front cover is refitted followed by the spindle and mounting block. I bought a spare motor to have for parts – it makes an interesting before and after.

2 comments to Wiper Motor Restoration

  • Anonymous

    What brushes did you use please?

  • James

    I'm afraid I don't remember, however they were not a good fit and had to be filed down to the correct size. Anywhere that sells good power tools should be able to get hold of replacement brushes, it's just a case of getting the closest available slightly too large size!

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