Consequence of failure to bleed coolant system

jonfrewin · Post by **jonfrewin** » Tue Nov 11, 2008 8:00 pm

My car has had a steady leak in its cooling system for years - the problem is, no garage has ever been able to figure out what is going on, because there is no visible leak, and pressure tests come up fine.

I have recently put a bottle of K-Seal in the system, in the hope that it may cure any possible head gasket leak. It then drank water like no tomorrow.

My question though is what happens if you do not bleed the system after a big drain - I've never done this when I've topped up, so might an airlock cause coolant to get pushed out of the coolant tank cap at high engine speeds?

I'm wondering if an airlock this might just be the cause of the coolant leaking...

Thanks!!

glasgowjim · Post by **glasgowjim** » Tue Nov 11, 2008 8:50 pm

check that your heater matrix is not holed cos it will leak down under the carpet and form a new ecosystem under uneath and you wont feel a thing.

Cerberus · Post by **Cerberus** » Tue Nov 11, 2008 9:25 pm

^^^^^^^^^
What he said.

Also have you checked the oil for mayo? Or the coolant for traces
of exhaust gas contamination?

Consequence of not bleeding your system would be an air lock. Unless
it's a really bad one then it will usually clear itself and you will have to
top up the coolant.

If you do a complete empty and refill you should really bleed the air out.
I used to get great air locks on the Spitty. Usually leading to a lock in
the heater matrix resulting in frozen body parts during the winter.

C

jonfrewin · Post by **jonfrewin** » Wed Nov 12, 2008 3:31 am

thanks very much both of you - i'll check for water in the driver and passenger footwells next time i get in the car. there is no sign of mayo in the oil, but i should also get some of those tablets to check for CO contamination.

glasgowjim · Post by **glasgowjim** » Thu Nov 13, 2008 12:24 am

heaer matrix usually leaks into passenger footwell.

The Xile · Post by **The Xile** » Mon Nov 24, 2008 11:55 am

My Celeb had a steady leak for years as well, usually requiring a full reserve refill every 3 weeks.
Found the problem to be a leaking hose, the one referred to as the "T" hose running from the back right of the engine to the bulkhead and also the oil filter housing. It was leaking from where the screw clip secures the pipe to the back of the engine. I just cut the perished end off and re-attached the same hose again. ( there was enough slack in the pipe to do this ).
This may still only be a temporary fix, but it has held well for 3 months now and no more water loss.
Just a thought

jonfrewin · Post by **jonfrewin** » Thu Nov 27, 2008 12:00 am

hey thanks - this might well be the answer - i notice that water goes really quickly when the car is overheating - pressure might be forcing water out and it just turns into steam on the engine block. there is certainly corrosion around the engine block where the coolant pipe attaches to the car!

Veegard · Post by **Veegard** » Sun Feb 01, 2009 1:27 pm

I've been noticing that under the carpet in my rhs footwell, there is moist under the carpet.. But I never understood where it came from. Perhaps my heater matrix is leaky? It also has air bubbles, but without the airing screw, how can I bleed the system properly? Try to just squeeze the hose until I get it all back in the expansion chamber?
And yeah, the hose clips are a pain to get off after a 10-15 years.. :/