401 Cooling

[Clive Foster]

Don't know about the Renault 5 thermostat but the three connection bottom hose type used on some Rover and Land Rover vehicles gives pretty much full flow bypass as they are effectively a change-over valve. For example part no PEM101021 is an 87° device listed for Rover 200, Rover 400, Rover 600, Rover 75, MG ZT, MG TF and 1.8 K series engined Freelanders. £40 for genuine from Rimmer Bros. Pattern probably rather cheaper. EuroCar Parts do a more generic Vernet branded one that lists for Honda, Land Rover Defender & Discovery too for under £30. There may be other vehicles that use similar devices.

My Range Rover P38 4.0 V8 has a similar but larger device with an extra stub for the heater which seems to work well.

As I understand matters you simply put a Tee connection in the top hose and run a hose down to the correct stub on the thermostat. The other two being for water pump and radiator. Cooling system diagram for the car it officially fits should make it clear how everything works but almost certainly two stubs up and oen stub down with the down one going to the bottom hose connector on the radiator.

Clive