Prestone Stop Leaks

Stop Leaks

Weight: 11 fl oz (325 ml)


Do not use in a dirty or partially clogged radiator. If cleaning is needed, use Prestone Super Flush. 1. With engine off and cold, remove radiator cap. Ensure there is room to add product. 2. For cross-flow radiators, pour entire contents into radiator. For down-flow radiators, add all the liquid and enough pellets to fill top tank to bottom of filler neck. Do not pack pellets into radiator. 3. Add 50-70% solution of Prestone antifreeze in water to top off system. Replace radiator cap. 4. Idle engine for 15 minutes with heater on then drive 5-10 minutes to disperse pellets. 5. Check for leakage. If leak hasn't stopped and you have a down-flow radiator, shut off engine and allow it to cool. Remove radiator cap, add remainder of pellets to radiator as in step 2, and top off system as in step 3. 6. Repeat idle/drive sequence as in step 4. If leak hasn't stopped after use of one bottle mechanical repair may be necessary. Pour in a bottle every time the antifreeze/coolant is changed and the system has been flushed. Helps prevent against future leaks. Protects the water pump. Corrosion inhibitors help stop rust and scale formation.

Product Details

Stops Leaks is scientifically formulated to stop cooling system leaks quickly. The advanced chemistry of the concentrated organic pellets quickly dissolves in the cooling system. The dissolving pellets seek and seal four problem areas where fluid loss occurs: the radiator, hoses, heater core and head gasket. Prestone Stop Leaks is a safe and highly effective way to stop cooling system leaks. Contains water pump lubricant. Corrosion inhibitors fight rust & scale.



Do not remove radiator cap while cooling system is hot. Harmful or fatal if swallowed. Contains petroleum distillates. Do not swallow. If swallowed do not induce vomiting. Call physician immediately. Keep out of reach of children.


Prestone Products, Corp.
Danbury, CT 06810-5109