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Ok people, I just got done doing this so the process is still fresh in my head. I may leave something out or make a mistake, feel free to comment and make corrections. I'm no expert, just a regular guy who is fairly handy with a decent set of tools. I wouldn't steer you wrong on purpose though so if I make a mistake PLEASE correct it. I'd hate to have somebody else get stuck because of something I wrote.

RANT! Skip this next paragraph unless you want a bit of an entertaining read and some background on me, your author.

I'm originally from PA, I grew up there, spent 21 years of my life there, 19 in the SE in Lancaster and the last 2 in Erie. Erie, is right on Lake Erie. The city experiences what is known as "lake effect" weather. What this means is that it gets @$$ cold there and snows a lot. What I'm trying to say is that I undertand the luxury, no, the necessity of heat in a car. I hate cold so when I graduated from college I moved my butt to the South and haven't looked back. Cold sucks, plain and simple. My hatred of cold drove me to change my heater core as well as write this. I hope it serves you well.

GOOD STUFF BEGINS HERE!!!

So here it is, the heater core is a dinky radiator that hides within the deep dark places within the dash of your car. It is connected directly to the coolant system of your car. The coolant in the system is hot under normal conditions, around 180F or so. As air passes through the heater core it gets warmed up and then blown through the HVAC plumbing and out the vents and we have heat in the winter to thaw frozen windows and stuff.

A heater core typically fails by springing a leak such as mine did. When this happens you'll get coolant leaking into the car which has a sweet smell to it. It's hot too and can burn your foot. This leak eventually lowers the coolant level and the car overheats. The diagnosis is pretty easy, now for the fun part.

If, in the event that the heater core fails it can simply be removed from the cooling system of the car. This is done by bypassing the heater core with a solid loop of hose. The fix is painfully simple but the downside is that you get no heat.

WHAT YOU"LL NEED TO BEGIN!!!

A good set of metric sockets with .25" & .375" rachets.
A set of metric box end wrenches.
Vice grips & pliers.
Some type of service manual, Haynes, Chilton, or a Ford factory manual.
Coolant drain pan, same thing is an oil drain pan basically.
A set of ramps makes it super easy, but a jack and jackstands work just as good.
A power screwdriver is super helpful too but not necessary.
A magnetic screwdriver with a set of driver bits that includes TORX bits.
Rags for sweat, tears, car fuids, and blood.

TO BEGIN!!!

Disconnect the negative lead to the battery. Give the system a couple minutes to drain down.

Pry off the bezel around the HVAC controls.

Take out the screws on either side of the center console trim that holds the HVAC controls and the radio. Do the same with the screws for the console piece that holds the shifter.

Taking out the seats may provide you more room to work but I didn't bother. I'm a pretty big guy and I got by with contortionism. This is your choice though.

Unscrew the shifter knob and take that trim piece out.

Take out the screws that hold the HVAC controls on.

Pull out the ashtry and take out the screw directly behind where the tray sits in the console.

Take out the radio if you can, you'll need a special tool to do this and I didn't have one. It isn't necessary but makes things easier.

Pull off the kick guards down underneath the dash on either side of the center console.

On either side of the heater unit there are white plastic cams with cables attached to them. These cams operate the paddles within the unit to adjust where air gets vented to, dash, floor, defrost, etc. Remove the ends of the cables from these cams. These cables are tied directly to the HVAC controls.

Now pull the HVAC control unit out until you can unhook the wire connectors in the back. Once you get those loose pull it all the way out.

If the radio is still in you can now get to the connectors in the back of it. Unhook those and take that out too.

Unhook the connectors for the cigarette lighter.

Remove the console.

Remove the trim piece to the right of the glove box.

Take out the passenger dash vent.

Take off the glove box.

Unhook the hood release lever from the trim. There was a nut hidden on the backside of mine and it took me forever to figure out how to get it off.

Take off the trim piece below the steering wheel.

This is optional, but you can take off the airbag for safety since you'll be screwing with the steering column. To do so, pop off the little round caps on either side of the steering wheel. Take out the bolts under those caps. Unhook the electrical connectors. Take out the airbag. BE VERY CARFUL with it and sit it somewhere out of the way and FACING UP. It can open and cause serious injury while being handled or if dropped.

Remove the trim on the steering column, top and bottom. 3 screws are on the bottom piece and clamshell around the steering column.

Unhook the little lignition light by twisting it and pulling it out.

Take out the bolts holding the steering column to the dash.

Lower the steering column.

Take off the instrument bezel.

Go under the car and unhook the speedo cable from the top of the transaxle. This will create slack to pull the instrument cluster out.

Pull out the instrument cluster and unhook all the cables in the back.

Pry off the triangular sail panels on either end of the dash.

Pull off the L shaped HVAC tubes on either side of the heater unit. These are right behind the radio and HVAC controls on either side of the heater unit like bull's horns.

Now the fun begins...

Take off the long black trim piece right at the edge of the window on top of the dash. There is ONE screw in the most idiotic spot right in the center. I had to put a TORX bit in it and turn it out with a pair of needle nose pliers. Once that is out, pry the trim piece up and remove it.

The dash is held in by 11 bolts.

3 along the edge of the windshield that were under the vent trim piece you just removed. These are the worst. Take the end ones out with a box wrench. The middle one you should be able to get a socket on, if not, use the box wrench.

4 under the triangular sail panels on the ends of the dash, 2 on each side.

4 at the base of the center console bolting the dash to the floor, 2 on each side.

Pull the dash free far enough to unhook all the cables and then pull it out.

VIOLA!!! The HOLY GRAIL IS WITHIN SIGHT!!!

Take out the heater unit.

Take the cover off from over the inlet & outlet of the heater core.

Pull out the old heater core being careful not to destroy any padding that may be around it. You'll want to reuse this. Do not use a hard insulator around the heater core or you may damage the new one putting it in.

Put in the new heater core.

Put the heater unit back on being careful not to smack the heater core tubes as you slide them through the firewall.

Put the dash back in and hook all your cables back up. Make sure your HVAC tubes get aligned correctly and that you aren't pinching any wires before bolting it back in.

Bolt in the dash.

Replace the trim along the window. I left that annoying screw out when I put it back on.

Replace all the trim pieces in reverse order of how they were taken off. Be careful to hook all your wires back up to the HVAC controls, radio, guages, light dimmer, etc. Also don't forget to put the hood release back on.

When reattaching the HVAC cables to the cams on the heater unit pay attention to where the cams are relative to the position of the control levers. Just mess with it for a bit and you should be able to figure out what goes where and how it works.

Hook the battery back up and get the front end up off the ground on the ramps. The car should start and run as it did before if you did everything right.

Put your coolant drain pan under the coolant hoses on the back side of the engine.

The heater core should have had a cap on one tube, leave this on. Unhook the bypass and attach it to the uncapped heater core tube. Tighten the hose clamp. Run another hose from the engine to the other heater core tube. Tighten the hose clamps. It helps to put the hose clamps on the hose before attaching it to the tubes in both cases. The factory clamps are one piece shoot metal rings. Compress the tabs with a pair of vice grips to loosen these, then release them where you want them over the tube ends.

Pour the coolant back into the overflow canister for the car.

Wash away any spilled coolant with plenty of water from a garden hose or a bucket.

You're done, enjoy the heat!

I have pics that I took that need to be hosted somewhere. I'll post a link to those later.

Thanks, be safe, and good luck!

[/b]
 

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Great How-To. I hope I never need it. :lol: I have had most all this apart at different times for other things I have done to the car and it seems to be right on.
 

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Discussion Starter · #4 ·
As my friend said to me just a short while ago on the way back from lunch...

"It sure is a good thing you replaced the heater core in time for this 80 degree weather..."
 

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You forgot to mention that if you neglect replacing or bypassing the heater core after it springs a leak, it can ruin your ECU. Since Ford was nice enough to put it right were it will get dripped on after it blows. :wink:

Hasn't happened to me but it could deffinately happen to someone.
 

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drivinonthinice said:
You forgot to mention that if you neglect replacing or bypassing the heater core after it springs a leak, it can ruin your ECU. Since Ford was nice enough to put it right were it will get dripped on after it blows. :wink:

Hasn't happened to me but it could deffinately happen to someone.
HaHaHa..happened to me, on my 95 lx heater core blew, and fried ecu, then i go to mech to get it fixed they put it in wrong and it blew again.
 

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THANX!!!!!

Dude, I've been three days tearing my dash apart, I think you just may have saved my mind. The Haynes manual descriptions and steps are very sketchy and poorly illustrated for this process.
My cars been running sweet with no major problems until my last 19 1/2 hour trip back from canada. Lets just say I crossed the border and stopped at a rest stop. When I restarted my car I noticed that infamous sweet smell. It was late at night and a little chilly but I smoke so I had my window down a crack. I noticed about two days before my departure that my radiator had about a pinhole leak but it still had enough pressure to take from the resevoir so I assumed I was just smelling fumes from a couple drops that may have gotten some where on the motor. Then the passenger side of my windshield looked REAL foggy. So I did the usual, DEFROST on HIGH. Looked like someone took a can of WD-40 to my entire windshield. And of course the car was Full of smoke. Then as if it were a problem chain, my transmission started grinding 2 hours later, 30 minutes after that I have an uncomfortable noise coming from my valve cover. Doesn't sound good , but I guess I'm gettin that 2.0 swap. Seems a little cheaper than rebuilding the top end of my motor. I guess the three trips to Canada and back to include all the rest of the rough roads this car has endured (anyone who's ever driven in Quebec knows EXACTLY what I'm talkin about) It hasn't been bad to me. And it still got me home. Where I've been stuck at for the last three days is the step right after you posted "heres where the fun begins". So all in all, I just wanted to say thanx. Your how-to may very well be my godsend. Peace, I'll let you know how it comes.
 

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Futhark said:
WHAT YOU"LL NEED TO BEGIN!!!

A good set of metric sockets with .25" & .375" rachets.
A set of metric box end wrenches.
Vice grips & pliers.
Some type of service manual, Haynes, Chilton, or a Ford factory manual.
Coolant drain pan, same thing is an oil drain pan basically.
A set of ramps makes it super easy, but a jack and jackstands work just as good.
A power screwdriver is super helpful too but not necessary.
A magnetic screwdriver with a set of driver bits that includes TORX bits.
Rags for sweat, tears, car fuids, and blood.
Doesn anyone know what sizes are these in Metric?
 

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WTF?

Ratchets don't come in metric. Only sockets do. He only quotde the Imperial ratchet sizes for good reason - you don't need to know metric equivalents.

You'll need a 1/4" and a 3/8" drive ratchet, plus several metric sockets.
 

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Thank you Futhark for this how to. I used it today to swap out my old heater core. I started at 8 am and finished up around 3 pm. I have more screws left over that I thought I would thou. :? I crack the my dash in putting it back in place. I was extremely dry so it didn't take much. Guess I'll be getting a dash cover soon.
 

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Thought I'd share a picture with you guys. I went in blindly and replaced one in my '95. Had the haynes manual, but didn't help too much once I got in deep. I thought I'd never get it back together...but it all worked out nicely.

The only thing I didn't take a picture of was the pile of bolts left over when I was done.

 

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thats the hard way

You dont have to remove the instrument cluster,dash,or anything up top. Droping the steering wheel only gets in the way.All I did was remove the heater control and radio ,center consol and kickpanels to expose the heater box .Then remove the clips on the box,one clip is up in back you cant see it but you can feel it.Now with the help of one of your buddys,each of you on a side pull the box apart far enough to get the core out.Be careful not to break the box you have enough room. Replace the core the same way CAREFULLY. Make sure to get the heater cams back in the same way they were before you took them out.Its not textbook but its half the work and time.Make sure to remove the computer before the core.
 

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First, let me say this is a great how to. I had a Chliton manual but there were a few things missing. I have finished swappin out the heater core o my 93 Ford Escort LX wagon and it was not overly difficult. I am adding some comments here that might help you.

I also separated the engine from the heater core. I simply plugged the two hoses off after removing them from the heater core. I then bought some 5/8 inch clear plastic pipe(cost 32 cents at the Lowes lumber store) and connected it onto the heater core to check that it was really leaking. I kept putting in water to see if it kept disappearing.

With the engine separated, I was able to monitor the coolant of the engine to make sure there were no other leaks. It is important to fill up the radiator at the top and keep filling it up after short trips until it doesn't go down. Also fill the overflow tank as normal. I was able to get to the point where no leaking was occurring in the engine and determined that the leak was in the heater core.

I used mostly a 7mm and 10 mm socket along with wrenches occasionally. In one case I needed an 8mm wrench and in another a 17m socket. I had a 1/4, 3/8, and a 1/2 in set. I used a swivel for the hard screw under the defroster bezel and that worked very well. I was able to remove it and put it back in.

I have a Chilton manual and some parts were not clear. Others were great. One important point is that after removing some of the parts, you remove the whole instrument panel with the pad attached. It is not necessary nor desirable to tear it down any further. This made it quite easy. In fact I did not feel that the project was overly difficult, other than the usual frustrations that always occur.

I wrote down all the steps for changing out the core and made notes as I went. I recommend that you write down each step and make notes of the colors, shapes, locations, etc. of each item and place the parts removed on a garage floor in order to make it easy to put them back in. I did not find it necessary to mark each connector as its description was quite satisfactory.

Some of these repeat information presented. The steps I took are as follows:

1. Disconnect the battery.
2. Drain coolant unless it is very low.
3. Disconnect the heater hoses from the heater core and cap them. You can use 5/8 inch plastic parts for lawns with some nylon tape for sealing. The cost for me was $3.00. This also allowed me to use the car and make tests until I got toward the end.
4. Unscrew two bolts on the glove compartment and remove it.
5. Remove the ash tray by the normal method of emptying it.
6. Prey out heater/ac control panel outer trim(bezel) (above radio) to reveal bolts underneath. Use a small thin screw driver and work slowly and there should be no problems. There was a clip on each side. I started at the bottom middle and worked out from there.
7. Remove 4 screws from parking brake cover and remove.
8. Unscrew shift handle( acts like a big nut), remove two screws on sides and pull it up at back to remove it.
9. Remove panels on the ends of the main dash near the doors. These snap in. Slowly pull it up with a screw driver. Mine caused the metal part for one of them to snap off with a bang but it was no problem. Just locate it as you are taking it a part and push it back on.
10. There are three controls on HVAC. Each has a clip and a loop that fits on the device it controls. Before removing them, I would use some white paint and mark the cable cover at the clip. Then after dry, use a black thin permanent marker to mark the end of the clip's location on the cable cover. This allows you to realign it without having to do any thing else. I also marked parts of each device with the controls moved to the left on the main panel to verify their reinstallation. Not how each device works when the controls are moved. One device is on the driver's side of the heater unit, another is on the passenger side. Both are in full sight. The third is buried to the right of the glove box opening but is easy to get to. After marked, pull each out of the clip and slide the ring off of the device.
11. Remove the 4 screws from the front HVAC control panel and pull it out. There are two electrical connectors. Remove them and note the locations of the 3 cables so they can be put back in the same place. Remove the control panel.
12. Disconnect cigarette lighter. There are two connectors.
13. I left the radio in and removed the whole assembly. There were 4 screws at the top of the center instrument panel(one hidden), Three at the bottom(One is hidden and one is behind the cigarette lighter. Removing several of the capstan screws on the lower left panel will expose the hidden screws. You may want to remove the whole panel first. I just pulled it back and was able to remove the two screws, but I would probably remove the instrument cluster cover and the left lower panel first if I did it again to make it easier to remove the screws.
14. Pull the center instrument panel out and disconnect the radio from the back. There were two electrical connections and the antenna. The radio doesn't have to be removed.
15. I removed the steering wheel horn cover. There was one connector. I don't think this was necessary. I wanted to verify that I did not have an air bag. If you have one, you definitely need to remove it and protect against it being set off.
16. Loosen screws on the plastic shroud surrounding the steering column so that you can get to the bolts to lower the steering column.
17. Remove the 4 bolts(17 mm?) and let the steering column down so that the steering wheel rests on the front seat. You can put a box under it.
18. Remove the bezel (includes other parts of the dash) surrounding the instrument cluster. There were two connectors to remove.
19. I removed the 6 screws for the left lower panel and removed it. You have to disconnect the hood release. It simply fastens to the plastic. Just undo the nut all the way and put it toward you and it will drop down the slot. There were two electrical connectors and there was one snap in holding the panel. Just pry out to release it.
19. Loosen four screws on the instrument cluster. I reached up the back side to release the speedometer cable. I had trouble getting it loose. All that was needed was to press the plastic tubing near the cluster panel in towards the cable and it causes the plastic protusion on the other side to slip out of a groove on the instrument cluster. Simply pull the speedometer cable out towards the firewall. This is difficult because of the lack of space. I did mine by removing the other end of the speedometer cable from the transaxle as recommended. You can trace the cable back through the firewall. The VSS is located on top of the transaxle. The transaxle is toward the firewall from the engine, clutch assembly and is integral to the whole engine, transmission group. There is an electrical connector on side at the top of the VSS and the speedometer cable goes directly into the top. I simply pulled the cable straight up to release it and did not remove the electrical connection. I also removed the battery in order to manuever the cable through the firewall. I then pulled the instrument cluster out a short distance and then pushed the cable through and repeated until it was possible to disconnect the electrical connections and the speedometer cable from the instrument cluster. This worked well and I had no problem reconnecting the speedometer cable.
20. Remove the lower right panel. There were 4 screws.
21. Remove the bezel(plastic cover) for the defroster outlet to reveal the bolts holding the intrument panel to the cowling. There is one screw. The defroster bezel is also held in by 8 snap ins. Use a screwdrivers to pry it up. To reduce damage to the dash board, I used a piece of metal to distribute the pressure against the dash due to the screwdriver.
22. The rest is taken out as an integral section. This includes the framework and the dash. I used a wrench as recommended for the left and right screws under the defroster cover. I used a 3/8 in swivel socket extension for the center one to allow me to turn it without bumping into the windsheild glass. This worked well. I did have a problem when putting it back as the hole did not line up. I used a drill bit to widen the hole in the dash connector when I put it back in. There are three bolts on each side by the doors. There are 4 bolts near the floor below where the ashtray was. This has a pin on each side to hold up the structure and allows you to pull the whole dash board out without it falling.
23. Pull out the dash board rotating it on the two pins. You can look down through the windsheild and see everything that needs to be done and verify that everything is disconnected. Disconnect the electrical connections. One of the connectors on the driver side disconnects above the fuse box. A connector on the other side disconnects from the blower motor.
24. Remove the whole assembly. I sat on the passenger seat and lifted the instrument pane-dash assembly up and moved it out the passenger door stopping to set it down so that I could move over. It was not overly heavy.
25. The heater unit can be removed by unscrewing the three nuts as opposed to screws. Two are at the top and one is at the bottom on the passenger side. There is also a strap around the blower intake on the passenger side which should be loosened and removed. The screw device for the strap is underneath the intake. Mine came off without loosening it up. I removed the air connector at the base that feeds air to the back seats but did not remove the two horn like connectors to the defrost section. When I wiggled the heater unit out and down, the heater unit dropped down and the defroster disconnected and the heater core came through the firewall.
26. The rest is simple. Unscrew the screws holding the heater core in the heater unit. Take out the unit and replace it. I reused the foam around it by tearing it off and put it on the new core. Maybe one can get new foam but it looked satisfactory.
27. Put back in reverse order. Had some difficulties here and there but on balance it went smoothly.
 

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Two things I learned when I changed my heater core:
1. Use a digial camera and take plenty of pictures before unhooking or unbolting things.
2. Don't flex the dash when you take it out or it will crack.
3. Use a step by step like above and not the directions from the Chilton or Hayes manuals, our FEOA directions are much better. There are a few people who've posted their step by steps so use the search button and pick one that you like.
 

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Guess who's heater core just started dripping before the 1400 mile drive to Myrtle beach? :cry: :cry: I just bypassed the heater core for the trip. I really need to work up the ambition to rip and tear at this baby. :roll: Man, at least it's not cold yet. 8O
 

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Mine went bad this summer too. :( I haven't had the time to rip it apart yet, since the car is a daily driver, so mine's bypassed for now as well. I'm dreading the day I finally have to do it...
Well, at least it will give me an incentive to replace my burned out left turn signal indicator... :mrgreen:
 

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replacin the core

well guys I just did this one on my 95 lx sedan, lets just say that it was a little on the frustrating side, it can be done as per the easy way as posted on page one, the only add on here that I would offer is to glue a tab with a string onto the end of the heater cams so that it will be way easier to line them up. Words of wisdom here is that it only takes about an additional hour to remove the upper dash portion, just make sure that you are labeling the wires you remove with tape to ensure that you reconnect them properly or use a digital cam as suggested before. Also ensure that after you put the new core in and reconnect the hoses that you bleed the air out of your coolant system, just pop the rad cap loose when you first start her, it will bleed off the air pressure. And as an additional word to the wise, cover the damn computer with a metal plate (I used a piece of aluminum plate) to sheild it from any further core leaks cause the dumbasses at ford put it right under the bloody core. I bent it so that it completely covers the top and bolted it on the computer bracket that it clips into. All in all I rate this as a 5 out of 10 for difficulty if you follow the long way of doing it.
 
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