Fluid Leak Diagnosis

Systematic diagnosis of fluid leaks on the 2022 Rivian EDV 500 electric delivery vehicle, identifying leak source and severity across cooling, brake, differential, and washer fluid systems.

Warnings

Tools required

Parts

• Shop towels × 1 — Consumable
• Absorbent floor pads × 2 — Consumable

Preparation

1. Park vehicle on level surface and apply parking brake
2. Place wheel chocks behind rear wheels
3. Verify vehicle has been inactive for at least 2 hours to allow cooling system to depressurize and cool
4. Place absorbent floor pads under vehicle to capture any active drips
5. Document initial leak location with photos from underneath vehicle
6. Verify 12V battery is charged (needed for cooling system pressure testing)

Procedure

1. 1

   Initial visual inspection from above
   Open hood and inspect engine bay for visible fluid traces. Check EV motor cooling system reservoirs, brake master cylinder reservoir, and washer fluid reservoir levels. Document reservoir levels and compare to normal fill marks. Look for obvious staining or fluid residue on components.
2. 2

   Raise and secure vehicle
   Lift vehicle using floor jack at designated lift points on chassis rails. Secure with jack stands at all four corners, ensuring minimum 18 inches clearance for undercarriage access. Verify vehicle stability before proceeding underneath.
3. 3

   Clean undercarriage for leak identification
   Using brake cleaner and shop towels, clean suspected leak areas on undercarriage, focusing on areas below reservoir drops noted in step 1. Clean front and rear differential housings, transfer case housing, brake lines, and EV cooling system hoses. Allow to dry completely before proceeding.
4. 4

   Inspect EV battery and motor cooling system
   Trace all cooling hoses from battery pack to front and rear motor assemblies. Inspect cooling system quick-disconnect fittings, hose clamps, and rubber hoses for seepage or crystallized residue indicating EV Battery/Motor Coolant leaks. Check underbody cooling system heat exchanger for corrosion or impact damage. EV coolant typically appears pink/red when fresh.
5. 5

   Examine front differential assembly
   Inspect front differential housing for gear oil seepage at axle seals, pinion seal, and housing cover. Look for fresh oil on differential mounting points. 75W-90 GL-5 gear oil will appear amber/brown and have distinct petroleum odor. Check fill and drain plug areas for weeping.
6. 6

   Examine rear differential assembly
   Inspect rear differential housing similarly to front, checking axle seals, pinion seal, and cover gasket. Pay special attention to rear differential breather tube for oil migration. Verify no leakage from mounting hardware or through housing casting.
7. 7

   Inspect transfer case assembly
   Locate transfer case between front and rear drive units. Inspect for Transfer Case Fluid leakage at input/output shaft seals, case mating surfaces, and fill/drain plugs. Check condition of transfer case mounting points for fluid accumulation.
8. 8

   Inspect brake system components
   Trace brake lines from master cylinder to all four corners. Inspect flexible brake hoses at each wheel for seepage, bulging, or cracks. Check brake caliper bleeder screws and caliper mounting areas for DOT 4 fluid traces. Inspect ABS modulator unit for leaks at line connections. Brake fluid appears clear to light amber.
9. 9

   Inspect transmission fluid system
   Examine EV transmission housing and related cooling lines for EV Transmission Fluid leaks. Check transmission case gasket surfaces, output shaft seals, and any external cooler lines. Look for fresh fluid on transmission mounting points and bellhousing area.
10. 10

    Check washer fluid system
    Inspect washer fluid reservoir, pump, and delivery lines to hood nozzles. Washer fluid leaks are typically most visible and leave white residue when dried. Check reservoir for cracks and pump seal integrity.
11. 11

    Perform pressure test if coolant leak suspected
    If EV cooling system leak is suspected but not visually confirmed, connect pressure tester to cooling system per tool manufacturer instructions. Pressurize system to 15 PSI and observe for pressure drop over 5 minutes. Inspect all cooling system components under pressure with work light for active seepage.
12. 12

    Apply UV dye if leak remains unidentified
    If leak source remains unclear after visual inspection, add appropriate UV dye to suspected system per dye manufacturer instructions. For coolant systems, add through reservoir. Run vehicle briefly (1-2 minutes) to circulate dye if applicable. Use UV flashlight to trace fluorescent dye to leak source.
13. 13

    Document findings and verify leak type
    Photograph identified leak location with clear reference to nearby components. If possible, capture fluid on clean white shop towel to verify color and consistency against known fluid types. Note whether leak is active drip, seepage, or residue only. Measure approximate drip rate if active leak present.

Reassembly

1. Remove drip pans and absorbent pads from under vehicle
2. Lower vehicle from jack stands using floor jack
3. Remove wheel chocks
4. Store all diagnostic tools and clean work area

Verification

• Verify leak source has been positively identified and documented with photos and fluid type confirmation
• Confirm leak severity assessment (seepage vs active drip) is recorded for repair prioritization
• Check that all reservoir levels have been documented for baseline comparison after repair
• Ensure diagnostic findings include specific component identification (e.g., 'front differential passenger-side axle seal' not just 'front differential')
• If UV dye was used, note this in service records for technician performing actual repair

More procedures for this vehicle