I checked the volvospeed site for heater core repair on an S70, site listed a repair for an earlier model, said something about the O rings failing in the quick connects often being a cause of coolant leakage...anyone know if this is true of an S70??

While the O rings do fail, it is usually the heater core that fails first. Once the lines are removed from the core, the O rings MUST be replaced.

Klaus
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The 164 has a new home, all I am left with are a 95 854T and a 98 V70R :)

This might be some help to you. I replaced mine recently. Overall a pretty straight forward job.

New Behr heater core form FCP Groton 138.00 (10/2007)

The only tool required is a Torx screwdriver with assorted sized bits.

You also need some old towels to catch the coolant that will spill out when you pull the heater core free.

It is NOT necessary to remove the dash or console.

Takes only an hour to R&R the heater core. May take the rest of the day to get the coolant out of your carpet. We were lucky and caught it early.

1) Squeeze the plastic latches where the heater hoses plug in to the fire wall and pull them out, noting which hose went in which hole. Secure them up high enough so no coolant spills out.

2) Loosen or remove the two screws in the galvanized plate where you just removed the heater hoses. Those screws hold the water tubes to the cabin side of the firewall.

3) Remove the screw below the steering colum that holds the lower shroud under the dash. Drop it down, unplug the courtesy light, and pull it free.

4) Pull the carpet away from the side of the console up next to the gas pedal. Pull it back as far as you can. Check for coolant under carpet.

5) Snap the black plastic panel off its snap under the console 'skin', then slide it toward the rear of the car to disengage it from the heater core housing. You should now clearly see the white plastic heater core housing, and the two water tubes coming down from the firewall.

6) On the passenger side, loosen the glove box and then remove the lower shroud and the black plastic panel, just as you did on the driver side.

7) Remove two Torx screws from each side of the heater core housing that hold the bottom half to the top half. (one horizonal and one vertical on each side). Remove the Torx screw between the water pipes that hold them to the bottom of the heater core.

8) Get your towels ready. Now pull the bottom of the heater core housing down and rearward so that it disingages from the water tubes. Unplug the A/C drain hose from the floor and pull it aside so that the heater core will slide out easily toward the passenger side.

9) Unscrew the heater core from the bottom half of the heater core housing and, like the books say, assembly is the opposite of disassembly.

10) To remove the coolant from your carpet, a carpet shampoo machine with an upholstery attachment is useful. You may need to remove your front seats if it is bad.

11) (added by Hawkeye) Using a section of hose blow some compressed air into the top heater hose connection under the hood. This will force most of the coolant out the bottom hole. I did this and a very small amount of coolant came out of the heater core when I removed it from under the dash
Hawkeye

Hawkeye has a decent right up but there are a few things that you might want to change up a bit:

Do not remove the pipes from the block connector at the firewall. If you do you will need a new set of O rings and spacers and you run the risk of cracking or breaking the plastic block that they snap into. Instead, simply remove the screw that secures the pipes to the bottom of the heater core itself. There are two simple O rings there that seal it, make sure you go back together with new ones.

On the whole coolant mess thing, take an empty coolant jug, the rectangular ones, not the round ones, and cut straight across the top so you remove the handle and poor spout, now cut about 4"off of the front and sides of it so all you have left is the flat back and the bottom which should be about a 4" deep rectangle to catch your coolant. When you undo the screw on the bottom that secures the pipes to the core make sure that you have the long flat back piece of your coolant catcher slid right up underneath the core/pipe connection. If you do it properly the coolant will flow right out and into your modified catcher and get not a drop on the carpet.

While I have yet to see them leak from the O rings, I have seen quite a few of the firewall block fittings crack and break. They are so notorious for it that any time I go in to replace heater hoses I always forewarn my customers that they may be buying a block if it goes bad.

Mark

You've already got the most important thing covered, you bought a Behr/factory replacement part.

Mark