heating/cooling radiator problem

[duka]

one year ago i had a big problem with the heating/cooling radiator!Temperature had gone to red and it exploded and hot liquid burned my legs but nothing serious...because i was lucky that i wasnt driving the car...i was standig still on parking(pure luck!)...and since then, i have a constant problem with heating/cooling radiator...after few months it starts to leak...drop by drop...and then i have to replace it with a new one...i really dont know what seems to be the problem...something wrong with the cooler maybe?or just bad
quality of that part?(what i think that is)anyone had the same
problem?thx in advance...

[wrinx]

That's the heater "tap", which allows you to switch between hot and cold settings.

Not sure why it would have exploded???

Perhaps you are having the same problem as me...does coolant overflow from the expansion tank in the engine bay? I wonder if the cooling system is pressurising?

Also wondering why it is leaking, do you replace the rubber seal?

wrinx

[duka]

That's the heater "tap", which allows you to switch between hot and cold settings.

Not sure why it would have exploded???

Perhaps you are having the same problem as me...does coolant overflow from the expansion tank in the engine bay? I wonder if the cooling system is pressurising?

Also wondering why it is leaking, do you replace the rubber seal?

wrinx

yes thats the heater "tap"...i tried replacing the rubber seal but no luck again the same.The coolant does not overflow but i think
that the pressure in my expansion tank is to big(and the weakest part in heating/cooling system is heater "tap")...i thought that the cap on my expansion tank is broken...i think 1bar is the pressure...i replaced with a new one and again the same...

[wrinx]

Coolant cap pressure is 1.5 I think. Something odd going on, perhaps you have an airlock near the tap???

How have you bled the air out of the system...with the heater controls on hot?

wrinx

[duka]

perhaps you have an airlock near the tap???

wrinx

thats possible but how can i know that,i mean how can i check that out?after i installed the tap i bled out the air on hot......maybe ill have to take my Q4 to some mechanic and let him find the malfunction...i'm tired of replacing the tap...

[AlfaJack]

I am replacing the tap on mine tomorrow. It has been weeping for ages and when I put the heater on the other day a drop of water (boiling) dripped on to my foot!!

The seal is quite hard to get right. Also, the taps currently available do not match to a Q4 chassis number - I will see the comparison tomorrow.