HYUNDAI/KIA 985102C100 MOTOR PUMP ASSY

The Hyundai/Kia 985102C100 is the Windscreen Washer Motor & Pump Assembly fitted to a wide range of Hyundai and Kia passenger vehicles spanning approx. 2001-2014 production. Hyundai's official catalogue identifies it as "Motor & Pump Assembly — Wind Shield Washer" (Hyundai part code 98510A). The unit is a submersible 12V DC permanent-magnet motor with integrated centrifugal impeller, mounted directly into the washer fluid reservoir via a rubber grommet seal. Activation from the wiper stalk delivers pressurised washer fluid through a single outlet barb to the windscreen jet nozzles. The 985102C100 has been progressively superseded in the Hyundai/Kia catalogue (98510-2C100 → 98510-2L100 → 98510-2V100 current production), all references identifying physically interchangeable pump units.

The washer pump performs four integrated functions to deliver pressurised washer fluid on driver command: (1) electric activation — supply circuit from the wiper stalk through washer pump relay (controlled by BCM on modern Hyundai/Kia with CAN-bus body electronics) provides 12V to the pump motor when the wash function is requested; (2) submerged motor operation — the pump body is fully submerged in the reservoir's washer fluid, which provides essential cooling and lubrication for the DC motor windings during operation; (3) centrifugal pumping — the impeller rotated by the motor creates centrifugal pressure in the volute housing, drawing fluid from the reservoir and pressurising it to 1.5-3.0 bar at the outlet; (4) fluid delivery — pressurised fluid exits the pump outlet barb to the supply hose routed under the bonnet to the windscreen jet nozzles.

The pump body seals to the reservoir via a rubber grommet press-fit into the reservoir's outlet port. The grommet provides both a fluid seal preventing leakage from the port AND a vibration isolation mount supporting the pump in the reservoir. The pump motor uses a carbon-brush DC commutator design rated for intermittent duty cycle (typical washer activation 3-10 seconds, multiple times per drive); continuous duty operation (sustained run beyond 30-60 seconds) overheats the motor windings and accelerates wear.

Washer pumps fail predominantly through three mechanisms: (1) motor winding burnout from dry-run operation when reservoir is empty — the washer fluid lubricates and cools the motor; running dry for repeated wash cycles overheats the winding insulation and produces failure within a few minutes of cumulative dry operation; (2) impeller wear from abrasive contamination in the fluid (mineral scale, dirt, ice crystals); (3) grommet hardening / shrinkage allowing air ingress to the pump inlet, reducing output pressure progressively. Pre-emptive prevention: always keep washer reservoir at least 1/4 full and never activate washer with empty reservoir — the single most important factor in washer pump service life.

Hand-operated pumps and other pumps for liquids are classified under HS 8413.20 (hand pumps); automotive washer pumps as electric pumps may also be classified under HS 8413.30 or 8413.50 depending on jurisdiction interpretation. Confirm exact 10-digit subheading and applicable duty rates with your customs broker. Commercial invoice description: automotive windscreen washer pump, 12V DC submersible electric pump, plastic body with rubber grommet, single outlet, for passenger vehicle application.

Does NOT fit: Hyundai/Kia applications with rear washer circuit (separate rear pump applications) — rear wash circuit on hatchback / wagon / SUV Hyundai/Kia applications uses a separate dedicated rear pump with different OEM reference; Hyundai/Kia applications with headlamp washer pumps — high-pressure headlamp washer pumps use different references due to higher pressure requirements; Newer Hyundai/Kia applications (post-2014) — may use updated pump references such as 98510-2W500 (Santa Fe / Tucson 2017+) or other newer references — verify by OEM number stamped on existing pump; Hyundai/Kia electric & hybrid models — verify washer pump reference, may differ from ICE-equipped applications; Hyundai commercial vehicles (HD truck range, Universe coach) — different references for commercial vehicle washer systems; Genesis Motors luxury brand — uses separate Genesis-specific references for washer pumps. Always verify by reading the OEM number stamped on existing pump before ordering.

Difficulty: Easy. Estimated time: 20–45 minutes depending on reservoir access. Drain or remove reservoir before extracting pump — pulling pump with full reservoir spills several litres of washer fluid into engine bay.

1. 1
   Drain washer reservoir or remove reservoir from vehicle (consult Hyundai/Kia service manual for your specific model). Pump is mounted in reservoir's outlet port below fluid level; pulling pump with full reservoir = fluid spill in engine bay.
2. 2
   Disconnect wiring connector at pump — press release tab + pull connector body straight off. Do NOT pull by wires.
3. 3
   Disconnect outlet supply hose from pump barb. Note hose routing for refitting. Cap or contain any residual fluid in hose.
4. 4
   Pull pump body straight out from reservoir with steady rocking motion to break grommet seal. Do NOT pull by wiring connector or outlet barb — pull by pump body. Some applications require small flat-blade tool to release retention clip.
5. 5
   Inspect reservoir grommet port opening — confirm bore clean and undamaged; cracked / deformed opening will not seal against new pump grommet. Clean mineral scale / debris with lint-free cloth.
6. 6
   Compare new pump to old — verify dimensions, grommet profile, outlet barb diameter, connector pinout match exactly. Confirm OEM 985102C100 (or supersession 985102L100 / 985102V100).
7. 7
   Lubricate new pump grommet lightly with washer fluid or clean water — dry grommet requires excessive insertion force and may roll or tear. NEVER use petroleum-based lubricants on rubber grommets in washer fluid contact — petroleum swells and degrades rubber compound.
8. 8
   Push new pump firmly into reservoir port until grommet flange seats flush against reservoir outer wall with no gap visible around circumference. Confirm full seating by attempting to pull pump back out with finger pressure — should resist removal.
9. 9
   Reconnect outlet supply hose to pump barb with steady push until hose seats fully. Reconnect wiring connector with release tab engagement click.
10. 10
    Refill reservoir with correct-concentration washer fluid. Inspect immediately for leaks around grommet port — any visible fluid weep = incomplete grommet seating, remove pump and refit.
11. 11
    Activate washer system and verify: pump audible during stalk operation, fluid delivered to windscreen jets at correct pressure / pattern, no leak from grommet or hose connection, pump stops immediately when stalk released. Run several wash cycles to purge air from system.
12. 12
    Final visual inspection after 24-hour soak test — check for slow leak from grommet base. Reset any Hyundai/Kia BCM washer-fault DTCs with Hyundai GDS or generic OBD diagnostic tool with Hyundai/Kia module access.