Coolant Leak From Heater Core on Chevrolet S10 Blazer

The heater core under the right side of the dashboard may leak engine coolant which can puddle on the passenger front floor. The loss of coolant may cause an engine overheating condition. Our technicians tell us that removal of the dash board is necessary to replace the heater on these vehicles.

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Average mileage: 118,937 (53,000–200,000)
5 model years affected: 1990, 1991, 1992, 1993, more1994
14 people reported this problem
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Viewing 1 - 7 of 7 problem details
1992 Chevrolet S10 Blazer 53,000 mi,
heater core started leaking on right front carpet; tied off hoses,plugged one with wooden dowl and clamp.have been driving w/o heater....during tolerable winter conditions~~~~~~~`
1992 Chevrolet S10 Blazer 60,000 mi,
Replaced the heater core and installed a ground wire from the heater core to the chassis ground. Blazer now has 247000 miles and haven't replaced the heater core or the radiator since. Electrolysis is a terrible thing.
Core leak "fixed " by disconnect of hoses to fire wall w/caps, as i live in Fl.
Coolant leaked into the passenger side floor. Replacement of heater core was needed
1990 Chevrolet S10 Blazer 109,000 mi,
Coolant Leak at passenger side foot area. has to replace heater core
1991 Chevrolet S10 Blazer 200,000 mi,
No Heat - Large puddle in the passenger side floor.
1991 Chevrolet S10 Blazer 199,564 mi,
Heater core went out and antifreeze leaked in the passenger side floor board. A new heater core had to be installed