Rear seatbelt tension

[testbloke]

Having just bought a 2004 C coupe I am extremely anxious to remedy the follwing "fault" as it is safety related.
The rear seatbelts are a bit lethargic at recoiling back when unclipped, enough to pass an MOT (as it has recently been MOT'd) but not great.
However, having recently changed from a harness to a bigger seatbelt anchored child seat (and also finding out I have no isofix !), the only thing holding the car seat and my child in place is the seatbelt, which is now even more lethargic as it is looped around the car seat (seat is britax branded OEM version of Mercs kidfix).
Is there any guidence how to replace what I am assuming is a tensioner on the rear seat belt to get it back to factory condition.

Edit : to confirm, when fitted around the car seat, if my daughter pull sthe belt it remains in slack position and does not recall !

 

[television]

Remove the seat or what ever to get to it and pull the belt right out, carefully spray the roller at each end with PTFE and this should fix it

 

[testbloke]

Remove the seat or what ever to get to it and pull the belt right out, carefully spray the roller at each end with PTFE and this should fix it

Malcolm, thank you for your response. When you say remove the seat etc to get to it, I think I need to remove the trim on the rear quarter panel to get to it ? I cannot see a method of doing so.

 

[television]

I will look the information up for you, you may have to remind me later

 

[testbloke]

I will look the information up for you, you may have to remind me later

That would be much appreciated

 

[television]

Your VIN number I need the next 3 numbers after 203

 

[testbloke]

Your VIN number I need the next 3 numbers after 203

Vin number is WDB2037072A653206

Thanks
Kevin

 

[television]

OK printed off and I need your Email address, you can edit it out soon

 

[testbloke]

OK printed off and I need your Email address, you can edit it out soon

email address removed

 

[television]

OK and sent, you can edit out your address

 

[testbloke]

OK and sent, you can edit out your address

Many thanks Malcolm, very much appreciated.

 

[testbloke]

Okay, thanks to Malcolm, got this stripped down last night. There seems to be plenty of tension on the "reel", but by the time the belt is routed through the two guides there does not seem to be enough pull from the "reel" to bring the seatbelt back tight.
If you pull the belt fully out, it will retract all the way in quickly, but if you pull it only partially out, it is extremely lethargic at retracting.
TRied WD40 and PTFR spray ont he reel but no difference. Is this simply the spring (or whatever tensioner) on the reel is worn and needs replaced ? Is this a simple swap out on the rear belt (I don't think there are any pre-tensioners or other electronic gubbins on the rear belts) ?
Again your help is very much appreciated.

 

[television]

WD 40 should not have been used, it will kill the effect that a PTFE spray would have had.

All you can do is to replace the complete belt, no electric plugs does mean no pre tensioners