306 Xsi Header Tank Cap

[Garry 1]

Just an update to those it may concern.

 

With the recent threads regarding the hot running of the XU10j4RS lump (GTi6) I suggested using the 306 XSI header tank cap as it has a stronger pressure release spring, I use to find the old 205 one use to blow coolant out the top as the spring wasn't strong enough. During my recent trip to the ring I have found that the 306 cap does not seal properly, it will let air out by squeezing the coolant pipes, so not very good when the pressure builds and you want the water to stop boiling!

I fixed the problem over the weekend by putting a rubber seal under the cap to seal it off.

Also, I don't think the cap on the end of the spring seals properly either, again, fixed with anther rubber seal.

 

I think the way forward may be to use a 306 XSI header tank as well, has anyone tried this yet?

[Anthony 1,003]

I think the way forward may be to use a 306 XSI header tank as well, has anyone tried this yet?

The expansion tank is integrated into the radiator isn't it on 306 XSi's, like on S16 and GTi-6 models?

[welshpug 1,657]

yep, I dont know of any 306 models that have a separate tank, odd you have had problems with this cap as its the type of cap supplied by peugeot now not the original metal ones, I have one on my 205 and it seals perfectly.

 

maybe the seal was missing from your cap to begin with. don't forget that there's 2 clicks to them when you close/open the cap.

Edited August 20, 2008 by welshpug

[Bakes100 20 1 Cars]

A bit of info for you here, but i brought a new radiator for my 306 Xsi and my old cap wouldnt seal on the new radiator. It wasnt the spring that was the issue, it was that the rubber didnt touch the flat face to seal because the opening wasnt large enough. After opening out the hole a tiny amount it fitted fine and never had any problems sealing after that.

 

Not sure if this is the problem with you but maybe worth a look...

[Miles 331 1 Cars]

The 306 D Turbo's etc all run a seperate tank on the slam panel, not sure on how many outlet's it has thou

[Garry 1]

So they don't do the K plate 1.9 caps anymore?

 

I fixed the seal by putting a rubber sealing ring in side the cap (as there wasn't one), to seal between the cap and the tank, it is now very tight and needs mole grips to do it up (2 clicks).

 

I then found that the sprung section of the cap wasn't sealing against the inside of the tank either, as I could hear air coming out of the over flow pipe when squeezing the pipes. So I taped a gromet to the under side of the spring section too, although I now doubt if any air or liquid could get out as the spring may be too compressed. It did the trick thouugh and I managed 7 laps on Monday and it got me home.

 

I just need to solve where the air is coming from, whether its poor bleeding or the head gasket gasket is failing and compressing the system. Admitedly I got to the 'ring by just putting more water in, which probably just sat on the air lock and then got pushed out over time.

[taylorspug 7]

I just get the 20lb caps from my local motor factors, they can get a range of pressures and sizes, so you can get the correct one to fit the std header tank. They seal up fine aswell.

Edited August 20, 2008 by taylorspug

[Garry 1]

Thanks Miles, I will look into that.

[maxi 36 1 Cars]

I just get the 20lb caps from my local motor factors, they can get a range of pressures and sizes, so you can get the correct one to fit the std header tank. They seal up fine aswell.

 

 

 

Maxi