MVS Forums users yuckuJackD (photos, primarily) and Gsnyder (text) show us how to replace the heater core (aka “heat exchanger”) on a first generation Volvo S80.
- Before starting, turn your key to the II position and turn heater to full heat and full fan. Turn the key off. This will get the linkage discussed in the forum out of the way.
- Start by removing the Strut Brace (Long bar connecting struts at the top of the engine). It will make the hoses on the fire wall more accessible. Remove 1 bolt from the middle engine mount and 3 bolts from each side.
- Put a small can under the 2 hoses to catch the 2-6 ounces of coolant that will come out (I used a small rectangular Tupperware bowl). Squeeze the clamp by hand and twist the bracket counter-clockwise while pulling out. You don’t need any special tools for this.
- Remove the plate behind the hoses (2 small bolts).
- Inside the Car – Drivers Side Only
Remove the Panel under the steering wheel (2 torx bolts). Also remove the small side panel (1 flat tip plastic screw)
- Pull the carpet away from the heater core and from under the gas pedal. You don’t need too much as long as you have a full size towel and a small container. Fold it over and place the folded towel over it so that it covers the from under the core to under the brake pedal.It you fold it in half twice, it will be the right size as a rectangle.
- Remove the brake sensor by pushing the clips at the top and the bottom in with a screwdriver or pick and push it up out of the way.
- Remove the one torx screw holding the heater core in.
- Remove the 2 aluminum clips slowly and gently using a screwdriver.They can bend easily so make sure you pull them out straight so that you don’t bend them.
- Put the small container under the 2 aluminum pipes and pull the pipes out (I didn’t have any kind of tie at the top but you may have to cut it if you do.).
- You can catch about 8 – 10 ounces in the bucket and the rest on the towel.
- Use a zip tie and pull the 2 aluminum pipes close to the bracket that the brake sensor was attached so they will be out of the way.
The steering column bracket gets in the way.This job is way easier if you move this out of the way and moving it is not very difficult.
- Remove the lower plastic panel on the steering column (3 torx bolts). After you pull the bolts, the top snaps off first and then the bottom pulls off.
- There are 4 hex bolts holding the column in place. You can now reach the 2 closest to the seat from the column area. Then pull the 2 closest to the engine from underneath.
- There is one 13 mm nut holding the steering column in close to the firewall. Remove that nut. Now gently pull the column toward the seat – about 6 inches.
You will now have plenty of room to pull out the heater core and slide the new one into place. As you pull it out, some of the coolant will spill out on the towel or into your container.
When you reassemble, make sure you get the guide at the top of the column in place as you slide it back into place or you won’t be able to get the column back into place. Everything else is opposite of disassemble.
Hope this is helpful!