ok so I have a silver top, it is plumbed as per the photograph,..


zetec_plumbing

Where,..

yllow goes from the bottom of the header tank to the bottom of the rad,
green from pump to the back of the thermostat housing,
blue from the front of the thermostat housing to the top of the rad,
red is from the pump to the bottom rad hose
orange is from the back of the thermostat housing to the top of the header tank.

this is how it was plumbed for a while and all was good, I am fairly confident that it is correct,.. however,........

on two recent occasions where I have been out for a 30 min and also a 10 min thrash the car has been faultless until I have got back and parked on the drive.. the first time it blew the (blue) hose off at point A,... and then the second time today it split the (green) hose at point B.

so,...please help,... please, it is easter and I want to play...

I have thought that it might be the thermostat,,...sticking closed,.. but the rad gets hot,..

any thoughts gratefuly received

oh and Happy Easter

[Edited on 19/4/14 by HowardB]

[Edited on 19/4/14 by HowardB]

If all has been fine so far then the system must be working OK, could it be heat from the exhaust causing the issue? Maybe be worth checking the jubilee clips as they are in the best place to get roasted by the exhaust. If the pipes are being blown off the system presure must be higher than the blow off presure of the cap 15 psi?

A hose splitting linearly indicates over pressure which points to the rad cap not venting.

I would suggest a new pressure cap. (it might be cheaper to buy a new tank complete with cap off eBay. Search on Renault Clio expansion tanks).
Also drill the standard 2 mm hole in the thermostat.

[Edited on 19/4/14 by britishtrident]

Thanks guys. . I can check the system pressure. I can also pop a heat shield in there too. The bit that confused me was that it didn't happen during the thrash but afterwards. .. more checking required I think...

Got a better pic of the thermo housing? Got the bypass hooked correctly?

Green from the pump to the back of the thermo housing? that doesnt sound right to me..

quote:

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Originally posted by HowardB
Thanks guys. . I can check the system pressure. I can also pop a heat shield in there too. The bit that confused me was that it didn't happen during the thrash but afterwards. .. more checking required I think...

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Thank you. I will check the layout and check the pressure cap. Thanks again....

As well as checking the radical does your cooling fan operate after the engine has been turned off?

quote:

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Originally posted by rusty nuts
As well as checking the radical does your cooling fan operate after the engine has been turned off?

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quote:

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Originally posted by coozer
Got a better pic of the thermo housing? Got the bypass hooked correctly?

Green from the pump to the back of the thermo housing? that doesnt sound right to me..

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close_up

Yes that looks OK. What thermohousing is that? Is it dual action like the original?
I had a raceline rail on mine, no end of problems including boiling over, change back to the oe housing and that solved all my problems.

Thanks again. It is a dunnell one. It worked ok before
Just wondering if the cause of the problem might be overfilling the header / expansion tank. I have replaced the ruptured hose and will try again tomorrow

I ran the engine to temp with out the lid on the expansion tank, then when it had spewed out some water put the top on it,. Took it for a spin, and on my return everything seemed ok. Switched the ignition off and almost immediately the fan started.

so far so good

thanks for all the input everyone,.. really helped



[Edited on 22/4/14 by HowardB]