Car Leak Checklist
Identify and document vehicle leaks with this comprehensive guide. Learn to distinguish between oil, coolant, and brake fluid to prevent costly repairs.
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| Item | Priority | Who | Time | What to check (Pass/Fail) | If failed (Next step) |
|---|---|---|---|---|---|
| Engine Oil Pan | Required | DIY | 5 min | Dry seal around the pan and drain plug | Tighten plug or replace gasket |
| Radiator Hoses | Required | DIY | 5 min | No crusty residue or wetness at clamps | Tighten clamps or replace hose |
| Brake Master Cylinder | Required | DIY | 5 min | Fluid level steady; no wetness on booster | Tow to shop; do not drive |
| Transmission Housing | Recommended | DIY | 10 min | No red/brown drips at the bell housing | Check fluid level; consult mechanic |
| Power Steering Pump | Recommended | DIY | 5 min | No whining noise or wetness on pump/hoses | Top off fluid; inspect O-rings |
| Valve Cover Gasket | Recommended | DIY | 10 min | No oil pooling near spark plugs/top of engine | Replace gasket to prevent fire risk |
| Coolant Reservoir | Required | DIY | 2 min | Level between Min/Max; no cracks in plastic | Replace tank if cracked |
| Differential (Rear/Front) | Optional | DIY | 10 min | No thick, smelly oil on the pumpkin casing | Service seals and refill gear oil |
| AC Condenser/Drain | Optional | DIY | 5 min | Clear water is normal; oily residue is a leak | Recharge system; check for UV dye |
| Shock Absorbers | Recommended | DIY | 10 min | No oily film coating the shock body | Replace shocks in pairs |
| Fuel Lines | Required | DIY | 10 min | No smell of gas or dampness along chassis | Immediate repair; fire hazard |
| Windshield Washer Tank | Optional | DIY | 2 min | Blue/green fluid not dripping from fender | Patch tank or replace pump grommet |
| Oil Filter Housing | Required | DIY | 5 min | No drips following a recent oil change | Ensure filter is hand-tight and seated |
| Thermostat Housing | Recommended | DIY | 10 min | No pink/green crust around the housing | Replace thermostat and gasket |
| CV Boot Inspection | Recommended | DIY | 10 min | No thick grease splattered inside the wheel | Replace CV axle or boot immediately |
| Brake Lines (Hard) | Required | Shop | 15 min | No corrosion or dampness along the frame | Replace line section immediately |
| Water Pump Weep Hole | Recommended | DIY | 10 min | No coolant dripping from the pump pulley | Replace water pump and timing belt |
| Transfer Case (4WD) | Optional | DIY | 10 min | No fluid at the output shaft seals | Replace seals and check fluid level |
Use this table to systematically inspect your vehicle from front to back. Start with the engine bay, then move to the ground underneath the car, and finally inspect the wheel wells and chassis.
If you find a leak, take a photo of the fluid's color against a white background (like a paper towel). This helps the mechanic identify the fluid type immediately.