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Last winter, I noticed that nasty smell of hot antifreeze when using the heater/defroster. Fortunately, winter was nearly over, as it only lasts about six weeks or so. I made a mental note to change the heater core this fall, then promptly forgot about it.
A couple weeks ago, the water pump started leaking. It wasn't coming out the weephole, and the bearing seemed ok. Nothing looked terrible, and I assume it was gasket failure, only because I can't think what else it might have been.
I changed the water pump out and bought three gallons of antifreeze to flush and refill the system. After I had the water pump changed, I remembered the heater core, so I just filled the system with water to see if it leaked. I drove the yellow truck most every day this week, and the engine leak was gone, although I didn't test the heater. I figured it was probably still bad.
So Monday, I ordered up a new heater core from Performance Radiator. I went with them because they're in Phoenix, and they're one of the few suppliers of the brass/copper super-cooling radiator. The heater core was $60, considerably higher than "parts house" cores, so I expected a quality product.
Turns out the core is all aluminum. I was a bit disappointed by that, but at least the fins were the same width (thickness) as the frame, so it should be more efficient than the one I pulled out.
Yes, the job of changing out the core is a royal PITA. I think Ford started with the core, and built the truck around it. That's why they call it the core...
Engine compartment
remove the two hoses from the core (2 x hose clamps - 5/16)
Remove the ac hose access access panel (2 x 5/16 hex head screws)
Remove the gasket around the ac hoses
In the cab
Optional - remove the accordion rubber vent duct (3 x 7/16 hex screws). Use a socket
Remove the vacuum hose from the actuator
DON'T remove the clip from the blend door
Remove the cover (4 x 7/16 nut and 1 x 5/16 bolt). Use deep sockets and extensions
Remove the thermocouple. (2 x 5/16 screws) use a nut driver
Remove the cover (4 x 5/16 screws). Use a nut driver
Remove the screws securing the ac evaporator (4 x 5/16 screws). Use a wrench and a 1/4" drive socket
Pull the evaporator forward. It'll only come about six inches. Use a strong wire (dry cleaning hanger) to secure up, against dash
Two brackets secure the heater core:
Bottom bracket screws into bottom right and bottom towards the left
Upper bracket hinges on the left and screws on the right
(3 x 5/16 screws) use whatever you can get in there! I used a 1/4" drive socket/ratchet
Ok, that gets the old core out. Clean out the nasty old gasket, wipe up the antifreeze and clean out any other crap down there...
I didn't get any pictures of the core in the recess, cuz I couldn't get the camera in there, and when I did, I couldn't aim, focus or hit the button
There wasn't enough of the old gasket left to reuse, so I used camper mounting tape. A couple wraps of the core, and it went into its hole nice and snug.
Installation is reverse of removal...
So then it was time to flush the system.
Pulled the radiator cap, inserted garden hose.
Pulled the upper radiator hose from radiator, fired up truck, turned on the heater
Stuffed a rag into the upper radiator connector to prevent water from escaping onto fan
Moved upper radiator hose and splashed scalding water onto myself.
Watched in slow motion as rag blew out of radiator connector and into fan belts.
Quickly turned off truck.
Loosened alternator pivot, power steering bolts and ac pulley to loosen belts
Pulled rag out of bottom pulley
Reinstalled belts
Installed a suitable plug into radiator top connector
Put hose back in radiator and fired up the truck with heater on
Grabbed three bottles of water from the house. Spilled a bunch of water when removing bottle from dispenser
Once the water water ran clear from the hose, I switched to bottled water
After 10 gallons of bottled water, I was satisfied the system was sufficiently flushed. Water flowed nice and clear from the upper hose.
Turned off the engine
Pulled the lower radiator hose to drain the water, and got burned by water from the block/water pump
After the radiator finished draining, hooked the hoses back up.
Filled the radiator with three gallons Prestone green
Ran the truck to check for leaks. All is well!
Heater core from Performance Radiator. $60. Seems like a quality item
The work site...
Heater hoses to come off
ac cover plate to come off
Hoses off
Cover off
Blend door
Remove the accordion vent
Remove the diverter box
Don't remove the clip
Evaporator has 4 screws
Cover also has four screws plus 2 more for thermocouple
Next truck that I buy won't have that big a/c box. It took me one time of changing the heater core to make that decision.
I said the same thing before I got my '77 F100. It was everything I wanted except it had the big ac box. I finally caved after looking the whole truck over and figured it was worth the hassle. I remember my first core change when I was 17 on my '75 with the ac box. Worst car/truck experience ever. I was glad I had the forsight at 17 to carefully save the gasket. I don't know if they ever made replacements, but I remember going to the dealership in '99 looking for one and not being able to get one there after trying parts houses.
Good write up papabear. I'm actually about to go tear into my Bronco to replace the blower motor in its giant box so this will be a good refresher. I'll probably take out the evaporator though. At some point most of the ac equipment disappeared before I got this Bronco, so all that's left is the evaporator and one hose. Someone also ignored the sticker that says to service the ac/heater box from inside the cab, so its been pop riveted closed after they fudged with it. Some people...
James, my neighbor needs to change the heater core in his 84 E350 RV, I'm donating the core as I have 3 that are used spares, thanks for donating the instructions PBY. LOL
I don't have an A/C box but do have A/C, I'm guessing dealer installed? But anyway, my blower motor is out. And I'm dreading replacing it. Am I simply dreading over nothing? I haven't seen anyone even talk about working on the heater of a truck without the A/C box and that's making me think it might actually be really easy.
I don't have an A/C box but do have A/C, I'm guessing dealer installed? But anyway, my blower motor is out. And I'm dreading replacing it. Am I simply dreading over nothing? I haven't seen anyone even talk about working on the heater of a truck without the A/C box and that's making me think it might actually be really easy.
are you referring to the blower for the factory heater or the blower for the dealer AC?
the blower for the dealer AC is in the front right of the "air box". Much easier to access!
Must be heater core season. Mine ('69 F100) started dripping in the passenger side floor board about two weeks ago. I pulled the heater hoses off of the water pump and looped a short length of 5/8" heater hose from one water pump nipple and right back into the other one on the pump, as a bypass, until the new heater core arrived and I finally had some time to install it. A couple of mornings, while driving to work this week, I could see my breath while inside the cab.
Yesterday (Saturday), I removed the plenum (my truck doesn't [currently] have A/C) and swapped out the heater core.
Nice collection of leaves in front of the core and a dirt dauber nest as an added bonus.
I got it all back together and installed late yesterday evening. I put in fresh anti-freeeze/water, burped the air out and took it for a drive. I have heat and defrost again, just in time for the cold winter months.
So is aluminum the new standard for heater cores? I picked one up for my Bronco and it was aluminum. Is there a downside to using aluminum? I decided to replace it since I'm to the hilt in the heater box to get to the blower motor. I'll rinse out the old one and shelve it as a backup. Btw, I don't know how people replace the blower motor and not come to the conclusion that ac isn't that important. There's nearly no way to get to it without taking the evaporator out, which I planned on doing anyway. The good thing now is that heater cores will be a breeze. Without the evaporator in there you can nearly open the vent door on the cover and reach all the heater core bolts from there without removing a thing. Ahh, the way it should have been from day one.
So is aluminum the new standard for heater cores? I picked one up for my Bronco and it was aluminum. Is there a downside to using aluminum? I decided to replace it since I'm to the hilt in the heater box to get to the blower motor. I'll rinse out the old one and shelve it as a backup. Btw, I don't know how people replace the blower motor and not come to the conclusion that ac isn't that important. There's nearly no way to get to it without taking the evaporator out, which I planned on doing anyway. The good thing now is that heater cores will be a breeze. Without the evaporator in there you can nearly open the vent door on the cover and reach all the heater core bolts from there without removing a thing. Ahh, the way it should have been from day one.
Aluminum is less susceptible to galvanic corrosion than copper-brass.
Stray electrical currents present in a vehicle, due to bad grounds, also presents problems of electrolysis from the stray currents running through the engine coolant and degrading the radiator and heater core, whether they are made of copper-brass or whether they are aluminum.
Yep, it's heater core season. I changed mine two days ago. Temps dropped to 30's at night the last several days. When I put the new engine in the truck, I installed a new radiator and heater core. The core I originally bought was smaller than the factory "Deluxe Heater" core. A third of the air flow was bypassing the core which gave me very little heat. Now I've got the right size core and lots of heat. Just in time for a warm weather front.
Aluminum is less susceptible to galvanic corrosion than copper-brass.
From the link they seem to suggest that's true, with respect to modern vehicles. What about older trucks? Or maybe an aluminum heater core coupled with a brass radiator, isn't a good choice, or vice versa? Interesting link. Thanks for that.
"Since modern vehicles and parts are designed for aluminum components, there is significantly less risk of galvanic corrosion with an aluminum radiator."
