407 hdi belt tensioner

[keithm]

I have just fitted a new alternator and need to back the belt tensioner off so I can get the belt on . Can anyone help me out. Regards Keith

 

[driven]

All pretty much same. Tensioner about 4mins 20 sec in

 

[UNM]

on the 407 HDi, the tensioner is just below the alternator. Looks like you need an allen key to turn it. A 4mm drill bit or a nail should do to hold the tensioner in the released position as there are holes in the block and tensioner mount to allow this.
I think you will need to access from the drivers wheel side as it looks pretty tight going in from above. If you changed the alternator, you probably already know that.

 

[keithm]

Thanks very much do you know what size Allen key and where is the socket for the key

 

[UNM]

Thanks very much do you know what size Allen key and where is the socket for the key

Sorry for late reply, been away.
Looks like I made a mistake, it seems it is a regular spanner, not an allen key.

Have attached the relevant section from the Haynes manual. Not best quality, but hopefully you can see the important parts.
I reckon the bolt to turn is the one on the tensioner pulley itself, the allen bolt is in the centre of the tensioner and would probably make the whole thing fly apart (not ideal).

 

[keithm]

Thanks very much . I have been trying to get the tensioner back far enough to use the lock pin and will try again in the morning

 

[keithm]

I finally installed the belt today . Getting the tensioner back as far as it would go didn't give me enough space to get the belt over all the pulleys . The only way I got it fitted was to undo the top alternator bolts and just undo the lower ones so I could move the alternator to fit the belt over all the alleys . I the moved the tensioner to allow the alternator to swing into position and get the bolts back in . This is easier with 2 people . If anyone else has the same problems this would be with keeping in mind