Reoccuring Heater Tap Issue

[RazzaCaine]

About 6 months ago i was driving a long when my old heater tap and water pump decided to give up the ghost. i got a mechanic to replace the water pump as i dont know how to do that but i replaced the heater tap myself. the car ran absolutely fine for a couple of months until i had another problem with the heater tap. i replaced the heater tap and it turned out that it was the hoses having become loose so i have a spare heater tap. now today when i was driving the same issue has come about, coolant leaking out of the heater tap. this makes it the third time in 6 months so understandably im starting to get a bit p&@sed of with it...

im going to assume that the reason for this reoccuring fault has something to do with the way ive been replacing the heater tap and/or dealing with the hoses. as far as im aware when replacing the heater tap its just a case of undoing all the hoses and then connecting them back up to the new tap in the correct order and making sure that they cover the heater tap extensions sufficiently and are tight enough not to cause any leaks. im not forgetting to do something special here am i? i know it may sound like a dumb question but hey... im well aware that when you replace/fill the coolant you have to bleed the air out of the system and my method of doing this is somewhat dodgy (squeezing the radiator hoses to force air bubbles out of the radiator cap) as i have no idea how to use the bleed screws (will search this in a moment). could this be the reason why i keep having this problem due to not all the air being bled out of the system? or worse still could it be something to do with the heater box?? ill add that theres no coolant leaking into the passenger footwell...

thanks for the help...

[hako]

Some of the heater taps I've seen are made 'on the cheap' and it's possible you have somehow put extra strain on the vacuum diaphragm or the plastic tap body causing them to prematurely crack. I find they hoses will slip on real easy if you grease them with either silicone grease or vaseline...this way you don't force them and this puts less strain on the tap body. Also do not overtighten the hose clamps - just snug them up tight enough to stop the hose slipping off....over-tightening can cause them to leak.
By the way - good post....plenty of info on the problem and background. Good Luck.

[RazzaCaine]

i have located the current issue being due to coolant leaking out of the top of the hoses away from the car which goes into the heater tap and it seemed a little loose, same as what happened the second time round. i have tightened it up and have test run the engine for a short duration and the leak appears to have stopped. this now brings me on to my next problem. i figured out where the bleed screw is, i.e. hidden under the engine cover, and to my great joy discovered that the screw is threaded and will not budge... now what do i do? i bled the air best as i could by squeezing the hoses to force air out of the radiator cap but obviously this would not have got rid of all the air. i want to avoid going to a mechanic to get this issue fixed as its literally a case of replacing the bleed screw and i can do that once i can get the old one out. how do i get it out with a threaded head? any suggestions??

[hako]

If you drive around for a few days and continually check/top up the radiator you will eventually get rid of all trapped air. However, it is no big deal....r.half a cupfull of air trapped in the cooling system is not going to cause the engine to boil and should have absolutely nothing to do with heater taps failing.

[greenacc]

they say parking the car facing up a steep hill helps you get the air out the radiator cap. And maybe a good pair of pliers will be able to grip the bleed screw and turn it. No doubt holden would sell you a bew screw few about 5 bucks.

[RazzaCaine]

ill give the pliers a shot, i did try a spanner but as the screw is grooved around the edge it just wouldnt get grip on it. the pliers are a good idea though

[RazzaCaine]

If you drive around for a few days and continually check/top up the radiator you will eventually get rid of all trapped air. However, it is no big deal....r.half a cupfull of air trapped in the cooling system is not going to cause the engine to boil and should have absolutely nothing to do with heater taps failing.

hmm so i wonder why the hoses at the heater tap keep failing.. perhaps im overtightening them?? just to add another layer of detail here, i have noticed that on drives for more than 10 minutes, when i get out of the car you can smell burning coolant, plus at the heater tap there was solidified coolant from where it had leaked out of the hose. the odd thing is that this smell has been happening for a few weeks and until today the engine temperature has remained normal hence why i didnt get on to it sooner...