At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.
The heater core is a small heat exchanger located inside the
truck, similar to the radiator at the front of the truck. Coolant is
circulated from the engine through the heater core and back to the
engine. The heater fan blows fresh, outside air through the heater core;
the air is heated and sent on to the interior of the truck. For Toyota Pick-ups/Land Cruiser/4Runner 1989-1996 check this reference repair guide...
Heater Core - REMOVAL & INSTALLATION (see Figure 1)
Drain the cooling system.
Remove the heater unit assembly. Have alot of towels handy for the leakage of coolant that may spill into your interior.
Remove the fasteners securing the core to the unit, remove the plates and clamps. Pull upwards to remove the core from the unit.
To install:
Inspect the core fins for any blockage. Using compressed air, clean them.
Install the core into the unit placing the plates and clamps into position. Tighten the core screws.
Install the heater unit into the vehicle.
Fill the cooling system.
Fig. 1: Exploded view of the heater unit assembly-1996 4Runner shown
Heater Unit - REMOVAL & INSTALLATION (see Figure 1)
Have alot of towels handy for the leakage of coolant that may spill into your interior.
Discharge the A/C system (if applicable), using an approved recovery/recycling machine.
Remove the cooling unit (if applicable).
Drain the cooling system.
CAUTION
When draining engine coolant, keep in mind that cats and dogs are
attracted to ethylene glycol antifreeze and could drink any that is left
in an uncovered container or in puddles on the ground. This will prove
fatal in sufficient quantity. Always drain coolant into a sealable
container. Coolant should be reused unless it is contaminated or is
several years old.
Disconnect the hoses to the heater core. Tag each one so that it may be correctly reinstalled.
On some models you will need to remove the glove box assembly. On others, the instrument panel and reinforcement.
At the heater case under the dash, disconnect the ductwork from the case.
Disconnect the heater control cables from the heater case. Lift
the spring clip holding the control cable to allow the cable to be
manipulated. Don't deform or crimp the cables.
Disconnect the wiring harness to the blower fan.
Remove the three or four bolts holding the heater case to the
dash. Because the inlet tubes project through the firewall, the unit
will not fall straight down. It will need to be pulled into the
passenger compartment and then brought downward.
To install:
Lift the case into position and carefully place the inlet and
outlet pipes through the firewall. Install the retaining bolts holding
the case to the dash.
Connect the wiring harness to the blower fan.
Connect the control cables to their linkages. Each must be
adjusted so that the motion of the dashboard lever causes the correct
corresponding motion in the air door. Both the control lever and the
door must reach maximum travel at the same time if full function is to
be achieved.
Set the dashboard control to FRESH. Lift the adjustment clip and
adjust the air inlet cable towards the heater unit until the linkage is
at its maximum travel on Pick-Up and 4Runner. For Land Cruiser, adjust
the cable away from the case. Release the adjustment clip.
Set the dashboard control to VENT (Pick-Up) or DEF (4Runner and
Land Cruiser). Lift the adjustment clip and adjust the air flow control
cable towards the heater unit until the linkage is at its maximum
travel. Release the adjustment clip.
Set the temperature control to COOL. Lift the adjustment clip and
adjust the air mix control damper control cable away from the heater
case until the linkage is at its maximum travel on . For Land Cruiser,
adjust the cable towards the case.
Connect or reinstall the ductwork. Make certain each tube is
firmly and completely fitted on its port. A light spray of glass cleaner
serves as a good lubricant; don't use too much.
Install the glove box and/or instrument panel assembly.
Connect the heater hoses. Use new clamps.
Install the cooling unit (if equipped).
Refill the coolant, then charge the A/C system (if equipped).
their is a valve on one of the two lines going into the heater core that could be stuck shut. i would get the vehicle up to operating temp and feel the tempeture on both the lines. if one line is hot and one line is cold, that valve is probably stuck. sometimes the valve just gets stuck on the outside mechanism and a little lubricant will fix it. you should be able to open and close the valve manuely to check if its working.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
could be your heater core, um try checking the heater assembly in the dash, something may have broke so the heat isn't being switched over, and it is staying on cold. Regularly check the fluids in the motor and top up as needed
Antifreeze circulates through one side of the heater core and out of the other. The blower blows on the heater core and creates heat. When the heater core cracks some people opt to not fix it and not deal with replacing it. That's what is happening in your 4Runner. Antifreeze is leaking through the cracked heater core and spilling onto your floorboard, probably more on the passenger side. Until you fix this you may want to remove the hoses and put it back how it was because you are going to continually running your coolant system out of antifreeze.
If you have not removed the dash before then pay attention as you remove the wiring when removing it. The replacement of the heater core is a piece of cake... after you get the dash out.
There is a heater core bypass pipe that runs from the block (under the manifold) to the bacl of theengine where you will see a flat rectangular "sheet metal" thing with a pipe coming out of it. The a rubber hose connects. You need to pull the top air plenums and intake to get to it. The p[ipe flange bolts to the block with silicone rtv as a sealant.
The heater core is located in the heater box. To get to the heater box you must first remove the dash. Then remove the heater box from the firewall. Then seperate the box to get to heater core. Good luck.
×