Can you use stop leak more than once?
Also know, how long will stop leak last?
No, this product is designed to be left in the cooling system to protect from future leaks and overheating. How long does it take to see results? We recommend you drive / idle the vehicle for 15 to 30 minutes. In most cases the leak will be sealed instantly, but others will require up to 30 minutes.
Consequently, will Stop Leak harm my engine?
This antifreeze apparently neutralizes the stop leak so that it is no longer active as it has already sealed off the leak when the engine was run. It does not harm the engine in any way whatsoever and I have been using it for years on customer's cars who don't want to spend a bunch of money at that particular time.
Instant Cooling System Stop Leak. Permanently fixes radiators, head gaskets, engine blocks, heater cores, water pump housing, and freeze plugs. Won't clog cooling systems. Compatible with all types of antifreeze and coolant.