Coolant leak

CHRIS WEBSTER

MEMBER
1997 FORD RANGER
4.0L
6 CYL
2WD
AUTOMATIC
190,000 MILES

I replaced my bad water pump that was leaking out of the weep hole. The new one works great and no visible leaks from pump or radiator hoses. When the truck idles for a few minutes coolant leaks from under the firewall and drips down the driver's side of the oil pan. It will only leak if the truck is running and it is a drip or two every minute. The freeze plugs on that side are dry so I do not think it is them. I trying to learn what carries coolant to that area so I can start checking.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

Look for a four inch long rubber hose with a ninety degree bend in it hanging down from in front of the firewall, passenger side. If coolant is dripping from that, the heater core is leaking in the dash. That tube carries the water out that condenses on the AC evaporator when the air conditioning system is running. The drip pan also catches coolant leaking from the heater core. Be sure that hose is wet inside. If it is not, the better suspect is a leaking heater hose, possibly due to a loose or rusted hose clamp. Those go in usually right above that drain hose.

If you still cannot find the source of the leak, consider adding a small bottle of dark purple dye to the coolant, then check a day later with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. Auto parts stores will have the dye for the fluid being tested, and those that rent or borrow tools should have a black light.