The Chevrolet Blazer uses a coolant-heated radiator core placed in the dashboard to administer heated air right into the passenger compartment. This heater core deserve to come to be clogged and also leak, as it is generally the lowest allude in the coolant device and debris settles into it. Replacement of the heater core will take the average backyard mechanic about two hrs to finish.

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Remove the front dash panel by turning the reduced screws in a counter-clockwise direction, then unscrewing the single bolt on the lip of the instrument cluster and pulling the panel out. Remove the rear wiper switch and also the 4x4 switches, if applicable. Lowering the tilt wheel will enable the panel to be entirely removed.

Remove the radio, headlight switch module and glove box by turning their screws in a counter-clockwise direction.

Remove the main dashboard by unbolting it at the front, in between the windshield and firewall. There are six to eight bolts holding it in, and, as soon as they are rerelocated, the dash have the right to be pulled ameans from the firewall. Be cautious not to pull too a lot, as the wiring harness could become damaged.

Drain the coolant mechanism by turning the drain plug on the lower left edge of the radiator and enabling the liquid to fall into the drain pan. Uncapping the radiator can minimize the inner push.


Remove the heater core hoses, on the upper left of the engine bay, by pinching their hose clamps via a pair of pliers and pulling them off. Some models will certainly have screw-type hose clamps; turning them counter-clockwise will certainly loosen them. Period and also warm may have actually stuck the hoses to the core nipples, and also the hoses have the right to be reduced ideal at these nipples if vital. Leave sufficient hose to reaffix the brand-new core.

Unbolt the heater core"s mounts through a socket wrench in a counter-clockwise direction. Once the bolts are totally free, the heater core have the right to be maneuvered toward the windshield and slid out. Some coolant may splash out, so have actually a towel handy.

Relocation the heater core with a new one by sliding it right into area and securing the mounting bolts.

Reaffix the heater core"s hoses, rotate the radiator"s drain plug clockwise to cshed it, then refill the coolant system with a 50/50 percent mix of coolant and water.

Reconnect the dashboard to the firewall, then rearea the front dash panel and also fasten its instrument cluster screw and bottom bolts.

Crank up the truck and also add coolant until the heater core is filled and also blowing warm air.

Replace the radiator cap.


Using distilled water raises the cooling capability of the mechanism and also stays clear of corrosion.

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Do not enable animals or kids to come into call through the drained coolant.