I have to change my heater core soon. I smell coolant coming through the vents, but not under the hood. There is also a tell-tale layer of scum on the inside of the windshield. I've tried Aluma-Seal (because I really don't wanna do this), but I can still smell coolant.

My FSM is not encouraging me any, either. As far as I can tell, the entire HVAC unit has to come out to change the heater core. I'm not looking forward to this. If anybody knows any shortcuts, I'd love to hear them.

Oh well, at least I'll get all the leaves out.

 

I have used alumaseal as quick fixes on radiators before. Sometimes it works quite well. It is the only one I would use.

I had to pull the heads off a V8 because the headgaskets were leaking. The previous owner must have poured about 3 gallons of that brown rubbery barsleak in. Inside of the block was insulated from the water with a film of the stuff. Took a while to get it all flushed out of the block and had to replace the radiator.

 

Dave, I just looked at the my FSM and it looks like the heater and evaporator is an assembly. Unless you got real long hoses on the refigerant side you will need to pull the freon. Now would be a good time to replace the accumalator/dryer and o-rings and switch to R134. I have done the switch but not the heater core.

 

can you access it from the front of the firewall, dave? i've had my heat shield deal off since the 5" went on, and spent quite a few hours staring at the whole thing because i've got the same problem. haven't touched it yet though.

dave

 

Hey I wish there was a better way to replace the heater core. I have taken a hole day to change out a bad core it's a bear to get all the dash out an not break it. When u get in your new core use a coolant treatment to prevent it from rotting out again. Good luck

 

Put a can of black pepper in your radiator, it will work it's way to your heater core and your problem will go away. I was told of this cure many years ago by an old mechanic, I had my doubts. I was on a cross country move, Navy transfer, and somewhere in east nowhere and my heater core took a dump I tried it and it was still good when I sold the car about 6 years later.
Good luck
Donald A

 

It's a big job, but not too bad if you've done a bunch. Way better than a head gasket or transmission, for example. Actually, I don't think I've ever done a core or evaporator in a 1st gen before, but too many to count on 2nd gen trucks. Yours is probably easier.

 

Had to replace the evaporator in mine, and it was not fun at all. I had to take the windshield out to get to the screws along the top of the dash (but not before I cracked it thinking I could fit the screwdriver in there) Its a do-able job, but it does take a while.

 

i've considered taking my dash out to give it a fresh coat of paint. I've looked at all the bolts to take it out, It doesn't seem to difficult and should easily be done over a weekend. Good luck hope you get her fixed

 

Not bad, just an unbolt, unscrew, bolt back, screw back job. Take your time, make sure you've removed all necessary bolts and screw so that you don't rip half the dash out LOL. Get yourself a new heater core from Napa, they are bigger than stock, fit the heater box and heat much better than stock. If you have working AC, might as well replace the evaporator in there as well.

 

I know this is a redneck thing but how about bypass the heater core and get a plug in ceramic heater. done in 5min. Seriously if you need a hand Dave just let me know.

Michael

 

Dave
Done a bunch of them, heres how.
Remove coolant hoses. Evac Freon, remove insulation pad,blower motor and cover, disconect A/C lines from heater box (and pressure block), remove 6 (+/- 1) nuts that hold the heater box to the fire wall,
Inside truck,
remove glove box door, right kick pannel, heater controll, two screws that hold the air deflector (over the center hump) and deflector, two screws that hold air blend pannel(tucks up under the dash center) and blend pannel, dash brace( near the upper left corner of glove box opening), lower dash attaching bolt (just under the dash, right side kick pannel) and one attaching screw just above accelerator pedal.
Disconect elec conections from heater box, remove vacume lines & gromet from firewall, disconect blend cable (right side of mount under cable gently press tab in and pull cable straight up) remove heater box attaching bolt(under heater box on kick pannel)
Pull dash towords seat enough to let the lower dash mount catch on the door opening
pull heater box away from firewall. lower from under dash while turning firewall side of box towords floor. should slide out.

10 min easy

Hope this helps

Dont use pour in sealers...they dont differentiate a leak from a restriction and tend to seal steam holes in head gaskets and could plug you heater core altogether.

 

Glad to hear how easy it is,.............Dave , may I suggest you take a trip to upstate NY. You should be able to get there in 15 minutes their time.

 

Boy those are pretty good instructions, they should be added to the tech articles post. Oh good luck Dave, sounds like alot of fun either way.

 

I think I saw once on Myth Busters or something like that. Drop an egg in the radiator. That took care of their problem until they could get it fixed.

I think that is what they used. It was about 8 months ago.