ERR4685 | Cooling System O-Ring - 200Tdi, 300Tdi | Defender, Discovery, Range Rover
To check the stock of Genuine Parts before placing an order please use our Contact Us page
To check the stock of Genuine Parts before placing an order please use our Contact Us page
To check the stock of Genuine Parts before placing an order please use our Contact Us page
To check the stock of Genuine Parts before placing an order please use our Contact Us page
Land Rover Part Number: ERR4685 - Cooling System O-Ring
ERR4685 is a cooling system O-ring used to seal thermostat housing drain plugs, radiator top-up plugs and upper coolant hoses on 200Tdi, 300Tdi, 2.0 MPi and 4.0 / 4.6 Rover V8 engines. It provides the sealing interface to prevent coolant loss and should be renewed if it becomes hardened, cracked or flattened to avoid leaks.
Compatibility
- Defender (1987-2006) - 200Tdi, 300Tdi
- Discovery 1 (1989-1998) - 2.0 MPi, 300Tdi
- Range Rover Classic (1992-1994) - 300Tdi
- Range Rover P38 (1994-2001) - 4.0 V8, 4.6 V8
Frequently Asked Questions
ERR4685 is the sealing O-ring used at thermostat housing drain plugs, radiator top-up plugs and upper coolant hoses to prevent coolant leaks. It provides a pressure-tight seal and should be renewed if it shows signs of deterioration (hardening, cracking or flattening) to maintain system integrity.
| Model | Variant |
|---|---|
| Land Rover Defender (1987 - 2006) | Radiator (4 Cylinder TDi L/R) |
| Land Rover Defender (1987 - 2006) | Thermostat Housing (2.5L I4 300 TDi Diesel Turbo LR) |
| Land Rover Range Rover Classic (1992 - 1994) | Thermostat Housing (2.5L TDi) (From JA610294) |
| Land Rover Range Rover P38 (1994 - 2001) | Radiator and Cooling System (4.0L V8 L/R Petrol, 4.6 V8 Efi Petrol HC, 4.6L V8 L/R Petrol) ((V)TOWA999999) |
| Land Rover Discovery 1 (1989 - 1998) | Radiator and Cooling System (2.0L 4 Cyl MPi T Series Petrol) (From FA393361 to WA799999) |
| Land Rover Discovery 1 (1989 - 1998) | Thermostat Housing (2.5 Tdi EGR (Gem), 2.5L 300 Tdi) ((V)FROMMA081992) |
If you are unsure of compatibility with your vehicle, you can also confirm by checking against your V.I.N. Simply reach out to us with your V.I.N and desired part number via our Contact page or use our Finding Part Numbers page.
Replace the O-ring whenever the cooling system is drained for service or if the seal shows signs of deterioration such as hardening, cracking or flattening. Inspect the seal during routine coolant system maintenance to prevent leaks.
- C8 products are usually supplied by Britpart.
- L8 products are genuine Land Rover parts.
- Z8 products are normally supplied by Allmakes.
All products and accessories available on LRDirect.com come with a 2-year warranty.