Peugeot 405 Manual

Cooling system hoses - disconnection and renewal
Cooling, heating and ventilation systems / Cooling system hoses - disconnection and renewal

Note: Refer to the warnings given in Section 1 of this Chapter before proceeding. Hoses should only be disconnected once the engine has cooled sufficiently to avoid scalding.

1 If the checks described in Chapter 1 reveal a faulty hose, it must be renewed as follows.

2 First drain the cooling system (see Chapter 1). If the coolant is not due for renewal, it may be re-used, providing it is collected in a clean container.

3 To disconnect a hose, proceed as follows, according to the type of hose connection.

Conventional hose connections - general instructions
4 On conventional connections, the clips used to secure the hoses in position may be either standard worm-drive clips or disposable crimped types. The crimped type of clip is not designed to be re-used and should be replaced with a worm drive type on reassembly.

5 To disconnect a hose, use a screwdriver to slacken or release the clips, then move them along the hose, clear of the relevant inlet/outlet. Carefully work the hose free. The hoses can be removed with relative ease when new - on an older car, they may have stuck.

6 If a hose proves to be difficult to remove, try to release it by rotating its ends before attempting to free it. Gently prise the end of the hose with a blunt instrument (such as a flat-bladed screwdriver), but do not apply too much force, and take care not to damage the pipe stubs or hoses. Note in particular that the radiator inlet stub is fragile; do not use excessive force when attempting to remove the hose. If all else fails, cut the hose with a sharp knife, then slit it so that it can be peeled off in two pieces. Although this may prove expensive if the hose is otherwise undamaged, it is preferable to buying a new radiator. Check first, however, that a new hose is readily available.

7 When fitting a hose, first slide the clips onto the hose, then work the hose into position. If crimped-type clips were originally fitted, use standard worm-drive clips when refitting the hose. If the hose is stiff, use a little soapy water as a lubricant, or soften the hose by soaking it in hot water. Do not use oil or grease, which may attack the rubber.

8 Work the hose into position, checking that it is correctly routed, then slide each clip back along the hose until it passes over the flared end of the relevant inlet/outlet, before tightening the clip securely.

9 Refill the cooling system with reference to Chapter 1.

10 Check thoroughly for leaks as soon as possible after disturbing any part of the cooling system.

Radiator hose(s) -
bayonet-type connection
Note: A new O-ring should be used when reconnecting the hose.

11 On later models, the radiator hoses are connected to the radiator using a plastic bayonet-type connection. To disconnect this type of connector, proceed as follows.

12 Twist the end of the hose (with the connector) anti-clockwise until the clips on the connector are clear of the retaining lugs on the radiator stub, then pull the end of the hose from the radiator. Recover the O-ring from the end of the hose connector (see illustrations).

2.12a Twist the connector until the clips (A) are clear of the lugs (B)
2.12a Twist the connector until the clips (A) are clear of the lugs (B)

2.12b Recover the O-ring (arrowed) from the end of the hose connector
2.12b Recover the O-ring (arrowed) from the end of the hose connector

13 Fit a new O-ring to the hose connector, then reconnect the hose using a reversal of the removal procedure. Twist the end of the hose fully clockwise to ensure that the retaining clips are engaged with the lugs on the radiator stub.

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