What goes wrong with a Valeo rad?

[Alex Crow]

Curiosity got the better of me, so I popped the rad tank off a failed Valeo to have a look see.

Firstly, the oil matrix itself looks fairly sturdy, and I am certain it is sound - note that the sealing of the oil matrix unions, and of the coolant is performed by just one seal on each union.

On inspection the insdie of the rad tank has emulsified oil around the area of the matrix unions, so it seems gearbox oil was getting into the coolant here. The seal ring for one union had clearly not been seated very well, and had allowed gearbox oil entry into the rad, so we can assume the coolant was getting into the gearbox oil here also - the coolant is at a higher pressure that the gearbox oil when up to temperature. The pictures are a little fuzzy, but to summarise, the coolant entry into the gearbox oil cooler was due to innefective seals at the unions, one of which showed signs of having been badly seated.

Sorry for the long explanation, i did not have time to write a short one.

 

[Steve@Avantgarde]

Nice one Alex! Same old story, a few pence seal causes catastrophic damage.

 

[dieselman]

How exactly does this setup work. Is the AT cooler mounted inside the radiator end cap?

 

[Alex Crow]

How exactly does this setup work. Is the AT cooler mounted inside the radiator end cap?

yes that's it. in one picture it is sitting inside the end cap - or tank, in another picture it is adjacent to it.

when in place, the matrix inlet/oulet sit flush with the outer face of the tank. the unions, into which the pipes fit, screw into the matrix and form a seal against the rad and matrix at the same time with a 'rubber' washer. on one union this washer was nipped at the center and poorly seated, presumably in manufacture. the 'smoking gun' was emulsified oil around these unions, some of which can just about be made out in the (very poor) pictures.

after a certain production date these rads are supposed to be OK, and are still supplied looking pretty much identical. perhaps they now use a different washer or installation technique, or a thread sealing compound where the unions screw into the matrix.

 

[Zebra]

Please could this post be saved as a Sticky?

 

[HaydnM]

Interesting to see the part number for the seal has never changed part number or not listed on EPC having been changed. A0002770554

Normally car manufacturers change part numbers on parts for three reasons,

1/ Supplier Change ( Manufacturer )

2/ Design Changes

3/ Large increases on price

So it maybe the same part from the same supplier as normal

Would be interesting to see the same on a Behr rad to compare, one can only assume that these are sealed the same way, as there is only one part number for the seal ring.

So why does it seem that Valeo Rad is the main problem

 

[whitenemesis]

Materials used in manufacture?

 

[dieselman]

Most likely assembly technique or lack of thread sealing compound

 

[ALFIEBEARD]

So why does it seem that Valeo Rad is the main problem

Coz its French.

Alfiebeard

 

[HaydnM]

Coz its French.

Alfiebeard

Are Yes forgot about that one just like those Citreon's & Renaults, like lego

Bits fall off & you have to snap them back on again :lol: