Stop leak additives – Beware
Today we saw a Holden Commodore with a common adult – a failed heater tap leaking coolant. This is a very common failure and easily fixed.
A kit was installed which has the new heater tap and all 4 hoses with new clamps. When I went to fill the radiator with new coolant I found the tank filled with mud? not quite but it looked like mud. In fact it was a coolant stop leak additive that the owner had put in a couple weeks prior to repair the leak.
These stop leak additives can sometimes cause more damage then they repair. This vehicles radiator was blocked, it would not take in any water at all. The additive had to be dug out then the radiator and cooling system throughly flushed. So the additive didn’t fix the leak, yet it created more work.
In hindsight it would have been more cost effective to have a mechanic come out when the leak began to fix it properly. The lesson here is that stop leak additives are just a band aid over a wound, they don’t actually fix the damage.