Corvette Windshield Wiper / Washer Pump Repairs

Windshield wiper/washer pumps have three major functional components: a motor, a pump, and relays. Over time, these three can show signs of wear and require repairs.

Common Problems

Motor: Bearings get worn or lose lubrication. Shaft gets scored and needs to be smoothed. Windings need to be rewound.

Pump: Seals begin to leak and need replacement. Assembly wears causing pneumatic problems.

Relays: Contacts get pitted and dirty.

Troubleshooting & Repairing

Before you get into specifics, make a general inspection of the overall unit.

Does the unit have fire damage or appear to have been subject to severe vibrations (like those caused by an accident)?

These are telltale signs of major problems. If the unit was in a fire, the inside parts may be fused together and not repairable. If the unit was jolted in an accident, the motor shaft may be bent beyond repair.

Pump/Water Side

1. Check plastic cover for broken tubes & blockage in tubes. Water goes in middle and out two side tubes.
2. Remove plastic cover, then check & lube O-rings.
3. Check small bladders & clean 6 plastic circles for each one. If one of the tiny holes is blocked, it reduces output by 16%.
4. Check reservoir bladder for brittleness. lubricate outer edge with O-ring lubricant.
5. When you reassemble plastic cover, be sure orientation is correct.
6. In a pinch, use an aquarium Y-connector; but that will reduce output by half.
7. Lubricate outer edge of star shaped plastic piece using white lithium grease.

Motor

Do not disassemble this unless you have to!

1. Clean brushes, check for pitting.
2. Clean vertical grooves in shaft (use fingernail).
3. Visually check windings for breakage, if broken, throw out.
4. Check inside of core for scratches and damage, clean out grit.
5. Check bearing for roundness and lubrication.
6. Be sure all greased parts have sufficient lubrication.
7. To reassemble, use 3 hands.
8. Put springs back in place, and return brushes to position.
9. Drop bearing into position between spring assemblies.
10. Insert shaft into position, making sure bearing is seated correctly and shaft turns freely.
11. Holding smaller piece BELOW upper piece, insert shaft into position. Listen for springs jumping out of position.

Relay Assembly

1. Clean 3 outside terminal leads & BOTH sides of outside ground lead and ground strap. (Especially important if unit has been painted!) Scrape with screwdriver or use very fine sandpaper (black).
2. Use Ohmmeter set to R x 1 to check for shorts. Terminal readings to Ground should be:
   • Inside = 25
   • Middle = 1
   • Outside = Resistor value (e.g. 6 or 15)
3. Below wires coming from 3 outside terminals, check fuse. If it is no good, it will look burned. Replace if necessary.
4. Check inside for broken wires (unlikely).
5. Check for missing springs (one large, one small).
6. If unit is always ON, check solenoid unit in plastic.
7. Disconnect yellow* lead and test with ohmmeter by engaging switch. Should show even open/closed difference readings.
8. If readings are rough and irregular, remove solenoid relay. Carefully pry holding fingers back so they don't break.
9. Remove insulation and contacts. Clean contacts (they may be stuck together from the high voltage that has passed through them.
10. Reassemble, remembering that middle layer of insulation must be oriented to insulate on both the inside and outside of the case (tit out).
11. Return relay assembly to position and resolder yellow* lead.

* Wire color may be different depending upon your model year.

Outside Casing

1. Look for visible cracks or signs of a fire (if pump has leaked, then water will cause fire damage.)
2. Tape off all terminal leads and rubber parts.
3. Spray paint with high-heat aluminum manifold paint.

DO NOT use abrasion to clean casing, you risk getting metal inside!!

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Copyright 1996 Barbara Spear