Installation and removal of heater in a pickup To install or remove the heater in a pickup, the first step would be to take out the heater out of the truck and then remove the five screws that are located between the halves of the case. Unscrew the hose clamps and pull the hose core out and then insert the replacement core and attach the core tube to the water valve tube using a short hose and clamps. Reassemble the halves of the case and reconnect with the screws and replace the heater and ensure that it is operating properly. To access the front of an MPV, empty the engine cooling system, disassemble the instrument panel, disconnect the heater hoses, unbolt the instrument panel support, support the heater case and unscrew the mounting nut. Lift the case carefully, being careful not to spill the coolant in the core, and then lift out the heater core. Installation is done in the reverse, at which time the new sealer is used and the cooling system is refilled, and leakages are checked. To remove the rear, loosen battery ground, switch the rear heater temperature controller to warm, empty the engine coolant, disassemble the driver seat, disconnect the heater hoses and the wiring, and loosen the mounting bolts of the heater case in order to lift it out. Removing the core is as simple as separating the halves of the cases and install is likewise as simple, replacing any damaged sealer. Navajo Disconnection of the negative battery cable should be done as the engine cools down and coolant should be emptied but it should be in a sealable container. Unscrew the heater hoses in the core tubes and plug them in, disassemble the screws holding the heater core access cover to the plenum assembly and detach the cover. To take out the heater core pull it out of the back and downwards then insert the new core and seal in the plenum, reconnect the access cover and replace the hoses without over-tightening. Lastly, verify the amount of coolant in the system, release the negative battery cable, boot the engine, and check whether it has leakages.