Heater Matrix/pipe Leak

[lagonda 42]

There are 2 aluminium pipes through the scuttle, that are located by separate flanges & screws to the matrix itself. I've an ongoing problem with a leak that SEEMS to be coming from this point with the lower of the two pipes.

The flange bears against a raised ridge around the pipe, & the seal is achieved (ha ha) by an O ring that seems to be made of something more like plastic than rubber.

Anyway, to be sure, I bought the correct O ring from a Peugeot dealer. This fits but I have to say I would have thought it would need to have been slightly larger. Also it's rubber, whereas the original isn't. Needless to say I've fitted it, & it still leaks. I've pulled it apart again, filed a washer to sit against the raised area, to compress the new O ring a bit more ... & it still leaks.

Anyone else had trouble with this? I accept it's possible the upper pipe is leaking, difficult to tell as they're so close together, but that joint does seem to be dry every time I check.

Incidentally what a bloody stupid way of plumbing this in! Two fixed metal pipes coming out of the matrix, connecting to two hoses through the scuttle .... too obvious for our leetle French chums?

[jackherer 543]

Are the pipes to your matrix fitted with phillips head screws or 8mm hex head bolts? I often have trouble tightening the phillips screw type enough to seal without rounding them but the hex head type are never a problem (except for one that sheared once) so I always use them now. I can't remember when Peugeot changed from one type to the other but if you have the phillips screws I'd swap them for bolts.

 

BTW I agree it is a frustrating design, I disconnected mine at the beginning of summer when it sprung a leak and I've just had a huge fight with it to get it sealed again now the weather has turned colder.

[Chris H 10]

I had a similar thing recently and found it to be the rubber hose in the engine bay that goes on to the aluminium pipe. This was leaking slightly and the water was running through the gommet and into the car down the aluminium pipe and driping on to the floor.

[GLPoomobile 958]

I also had problems after replacing the matrix in a previous 205. I just put loads of black sealant around the O ring and fitted it back together and it was fine then.

[lagonda 42]

Yes, it's daft philips screws ... ideal for cam-out and inaccessibility! So good idea, I'll see if I've got some small bolts to replace them with.

I don't think it's the hose joint leaking, although it has been leaking previously, but justy down the outside of the scuttle. There's some foam sealing where the pipes enter the scuttle & I would imagine that would be wet if it was leaking through.

I did try silicone sealant on the original O-ring but with no success. Next step would be to try Hylomar which is hateful stuff to use, but seems to work when all else fails, except that I recently ran over the tube. In the dark, as you do, & then sister knelt on it because of course she couldn't see it, so that's those trousers ruined. What the chances are of forgetting I hadn't put the tube away, then out of a triple width driveway, running the tube over, let alone my sister having to kneel on the driveway for whatever obscur reason in exactly that spot just moments later are I don't know, but must be of lottery winning scale. But this is 205 GTi world, is it not.

[pug_ham 245 3 Cars]

New heater matirx's usually come with new seals for around the end of the two pipes, use them & imo you shouldn't have any problems.(& hex head bolts iirc).

 

If its leaking from the pipes in the engine bay then you might need to fit the new rigid pipes that also usually come with the heater matrix kit, I've had these rust through & start leaking after being disturbed to replace a matrix before. (they must supply new pipes for a reason).

 

Graham.

[lagonda 42]

Hi Graham, it's not a new matrix, so no new pipes. The pipes on mine are aluminium & appear OK. Plan on having another go at it once I've got a new thermostat from GSF.

Laurence