How do you install a new heater core in a 1992 Buick Century with the 6 cylinders?

Answer 1

remove heater hoses from pipes sticking through firewall on passenger side. Most of the rest of this involves standing on your head in the floor of the passenger front seat and probably getting an antifreeze shampoo. Remove the under-dash cover and open ductwork compartment to expose heater core. Remove screws holding it in place and pull it out under the dash. Reassembly is the reverse.

Additional comments::

I tried to find a post on how to remove the dashboard on my 92 LeSabre and really couldn't find a good one. I managed to piece together enough information to figure it out.

1992 Buick LeSabre Dashboard Removal Procedures to replace heater core and hoses

Car ramps or two jack stands. You need to drain the rad .Access the thumbscrew drain cock, located on the driver side at the very bottom of the radiator. To do this you need to raise the car to get a bucket under to catch the old antifreeze.

Be sure to start the car first and turn all the temp controls to OFF.

Parts and tools

New heater core

New heater hoses (don't believe what Autozone tells you; both heater hoses are exactly the same design and length. They will try and sell you one hose that is completely different than the top heater hose. WRONG!

Optional: new dash bulbs, new rad hoses and clamps (The bulbs cannot be replaced by pulling them out of the sockets.) You must buy them preinstalled. DON'T believe what Autozone tells you. They don't know.

Digital camera (to take pics to help reassemble

Notepad and pencil

ignition keys

thin flat blade screwdriver

Long flat blade screwdriver

Medium length Philips screwdriver

-T15 torx screwdriver & a ¼" drive ratchet, ¼" socket set (metric & standard), 3"- ¼" drive extension, plus 2 - 12" ¼" drive extension and 1 - 6" long ¼" drive extension

Assistant who has small hands and arms

Plywood to lay over engine for helper to assist in removing heater hose clamps and to install new hoses and clamps. Note the cable pliers are required to remove the factory installed ear clamps. There are 4 heater core clamps; two next to the firewall and two on the block. Each rad hose has 2 ear type clamps as well.

Standard short handle pliers

flashlight

needlenose pliers

Dremel tool with cut off wheel

Twine

Dish soap

Permanent marker pen

Large pot to boil water in

One hell of a lot of patience

This job will take 15 -- 18 hours if you take your time. Don't hurry or you will break something.

Hints & Tips: The plastics will be brittle and will break if twisted or forced.

The bottom lever for the vent door is composed of two levers. Carefully study the connection. Beware, do not twist the metal lever as it is held in place by a very fragile plastic keeper. I broke mine and had to find a plastic push nut and then glue the top of it. This lever has a 90 degree bend on the end which attaches to the actuator and is inserted from the bottom up. Why didn't they insert it from the top down is beyond me.

Most screws to be removed will be the ¼ " , T15 torx type.

All screws are not the same size and length. Use plastic sandwich bags and label them.

Procedure:

Heater core removal from the engine side

Lay out plywood sheet for assistant to lay on

IF you look directly down the fire wall you will see the end of the heater core hoses that connect directly to the heater core. You will also see a lot of wiring and a fuel line return that are in the way. Use some of the twine to tie these hoses etc towards the front of the engine to make a hole. Don't cinch them too tight!

Have your assistant guide the clamp end of the wire pliers down to the first hose and engage the ears. You then squeeze the pliers as tight as you can, while your assistant keeps their fingers out of the way. Once you have the clamps open, have your assistant slides the clamps back and over the ridge on the heater core outlets. Relax the pliers. If you are lucky, your assistant might be able to rotate the hose on the core pipes and then pull them off. If not, use your short handled pliers to rotate and break the seal on the hoses and then slide them back.

Repeat procedure for the bottom hose.

Remember when installing the new hoses outside the firewall, do the bottom one FIRST!

Remove the clamps on the engine end of the hoses using the cable pliers.

If for whatever reason the pliers won't clamp onto the ears, carefully use the dremel tool with a cut off wheel to cut the defective clamp. Then follow the removal procedure outlined above.

Now is a good time to renew the rad hoses. Cheap investment. If you go to Autozone they will try and sell you a bottom hose that is not the correct diameter nor does it have the wire coil inside to keep the hose from collapsing. Bring both rad hoses with you to make sure of the shape and diameter.

Now go to the inside of the car and disassemble the dash to expose the old heater core.

Photo shows new heater hoses in place. The new heater core has already been installed.

Now you can see why you need an assistant with small hand. There is no room to work those heater hoses in!

New heater hoses in place. Buy the screw type hose clamps to replace the ear type clamps. Use tape to secure just the backside of the clamp to the new heater hose. That way you will be able to use your socket or screwdriver to tighten the clamp. If you assistant has small hands they can spin the clamp to the right position, so you can tighten it.

Before installing, immerse the heater hoses one at a time in a pot of hot water to loosen them. Once you remove them, wipe the inside of the hoses with dish soap so they slide on easier.

New heater hoses attached to engine. Yes, the clamps are too long but that is all they had in stock. Be careful to install the clamps ahead of the ridge on the stubs.

New rad hose in place.

Bottom rad hose in place

Top rad hose in place

Dash removal section:

Step 1: Remove all dash vents by gently prying down on the top of the vent while gently pulling down and out. Gently pry up on the bottom of the vent while gently pulling up and out. You should be able to do this with a small thin flat head screwdriver. Gently pry the top and bottom and turn and pull with you fingers only and the vent will come out. DON'T USE A PAIR OF PLIERS!

Successful removal of vent. Remove the screws from all the vent ducts (once you remove the vent you will see the screw at the top of the hole), caution to not drop the screw down the duct. Stuff a rag in the vent to catch the screw if dropped and/or use a magnetic tipped driver. Okay, there is no rag, but I staged this pic.

Remove the screws on the glovebox box; two top and two bottom. The whole glovebox can now be lifted out of the dash. Remember to remove the passenger vent first. Otherwise the screw at the top of the vent will not allow you to remove the glove box.

Remove the bottom cover plate above the passenger floor mat.

This is the photo of the bottom trim piece with the light and module removed.

This exposes the heater cowling etc. Note that this panel has one courtesy light and the silver module that activates the "change oil light". Mine was not working so I went to GMC to buy one. They quoted $275.00. I found one on e bay for $18.00. Search by using the large print id number on the module. This module slides out of the slots in the bottom panel. Once out, unplug it and put aside.

Pic of oil change warning light module

Remove all exposed T15 torx screws and glovebox interior.

The plastic wood trim comes off in two pieces. Left of the steering column and right of the steering column. Gently pry the woodgrain from the dashboard. Again, only use the small thin flat head screwdriver.

Repeat this procedure for the opposing side. Make sure all the metal clips are still on the plastic tabs on the back of the wood grain. Don't forget the screws above the gear indicator and gas gauge, in the top of the main dash display.

Unlock the gear shift, press on the brake and put the car in 1st gear (be sure to chock your wheels or have the vehicle on a level surface). This allows you access to the bottom screws and makes the instrument panel easier to remove.

The portion of the dashboard surrounding the clear plastic dash display will be caulked to the black plastic dash. Carefully separate the caulk from the black or clear plastic all the way around the perimeter.

Now is the time to remove the clear panel that houses the gauges and lights. It has one plug in module no mechanical speedometer to worry about. Remove this panel and remove the metal spacer on the back of the panel. This allows you to access all the bulbs. Replace them, you don't want to do this job again, just to replace a burned out bulb! There are two types of bulbs; one has a white base the other a black base.

Note that the shift indicator is controlled by a thin wire cable. This cable clips to the steering column on the passenger side of the column. DO NOT BREAK this. Also mark where the cable clip goes on otherwise the shift indicator will read incorrectly when you reassemble.

Remove the gray (see above photo) plastic padded trim piece.

Note the hidden fuse panel when you remove the gray padded trim piece.

On the passenger you will see the two piece cowling that houses two doors that control the heat and temperature. Remove any plugs. There are two screws that hold this cowling together. The top lever is easy to disassemble. Just carefully lift up on the threaded end of the lever. This photo shows the new heater core in place with the heater cowling removed. The old core just slides out and the new one slides in.

Take notice of the red painted bottom lever. (I painted it red to keep track of it) Note how it fits into the actuation arm. I broke the old keeper piece so used a plastic push nut with crazy glue on the top for insurance.

You can just see the new heater core with red sticker in place at the top of the pic. The white lever on the cowling is the upper lever arm.

Pic shows new heater core in place. The new heater core should have a two hole bracket that clips onto the new heater core.

Second pic of one of the two part heater cowling. Note the orange plug is disconnected.

The bottom one is built with two levers; the first one is metal with a threaded end the second that attaches to the metal section is a u shaped plastic arm. Remove the plastic arm. Now you must be very careful when you split the cowling apart that you DO NOT BREAK the plastic keeper that you cannot see until you get the whole thing apart. The cowling does not come out easy. I had to twist and turn to get it out. That's when I broke the keeper on the bottom lever.

You now have access to all the components behind the dash panel. This is the perfect time to clean those air vent deflectors and address any squeaks or rattles in the dash. An air compressor is essential.

IF you unplug the connectors that the cowling has, it makes it makes it much easier to work them out. Now you will see the old heater core. (Silver piece to the left of the pic)

Again you see the Hidden fuse panel.

The two piece heater cowling is in place and now attaching the screws that attach the cowling in place. Note the upper arm is in place. Very important that you turn all temp controls to off so you don't position any of the control arms in the wrong position.

Reverse procedures to reinstall.