Alright guys, im trying to help a buddy diagnose the source of a coolant leak. First off, he didnt realize that you were supposed to dilute coolant with water, so would that cause an excess buildup of pressure in the radiator since pure radiator fluid would be more viscous? Secondly, i noticed a hose that comes out of the bottom corner of the passenger side of the radiator; its about 5 inches long and leads to nothing. The leak seems to be coming from this bottom corner, near the plug, and this hose. Is it just a drainage hose for some reason or should it be longer and connect to somewhere?

 

First of all, you have to be careful buying coolant today. Some are straight coolant and some are pre-mix. A lot of people don't want to mess around mixing it, so they buy pre-mix.

The way I always get it right is pour one bottle of straight into the radiator. Fill that bottle up with water and pour it in. Pour 1/2 of the second bottle into the empty bottle and fill both with water. Top off the radiator, bleed the air, and run to temp. Finish topping off the radiator and overflow bottle, mark both bottles 50/50 and save for later. Works every time.

Investigate that leak. Clean up the area with brake cleaner, start up and watch it. The radiator may have had a drain petcock with a drain hose on it and been replaced with a plug. Straight coolant won't cause more pressure but it won't cool as well as a 50/50 mix. Water is the best for removing heat but causes corrosion in the system and doesn't lubricate the seals in the water pump.

If it is a leak, it most likely is coming from a core tube and running down to where you see it. OR the side tank has a cracked solder seam.