S80 Heater core replacement

[shea44]

I hadnt heard that! Yuk!

[midimykeys]

Well, I took it to my mechanic, and he was able to swap out the o-rings, and only charged me $195! It's as good as new. And shea, you don't need to mess with the evap or a/c, that shop didn't know what they were talking about.

[kossmonaut]

pfft ive revived older threads

id like to thank xheart for all his advice, every bit was spot on. those clips will haunt me forever.

i too unseated one of the heater control arm linkages (dont think i broke it) and no longer am able to change temp on the driver side vents. if any of the other people here have figured out how to repair them or atleast a diagram id appreciate the help

thanks

[xiami]

I replaced my 2002 S80 heater core following the good information provided in this thread. Thank you everyone who contributed! There are two additional points:

1. To ease removing and installing the brake pedal sensor, there is a white collar under the mushroom shaped pedal that should be fully extended. When installed, pressing on the brake pedal retracts the collar into the cylinder of the switch which prevents one from depressing the tabs to release the brake sensor from the bracket. Very smart Volvo engineers to make the switch very difficult to come loose from the bracket.

2. To release the steering column, you need a Torx driver, not a hex driver to remove. I think it is T40.

Since I have to remove the heater hoses in the engine compartment, I replaced the 4 small turbo coolant hoses, along with all other coolant hoses in the car. The most difficult one is on the driver side turbo and that hose has delaminated and frayed at the clamp. This hose is mostly obscurred so you can't even see the hose without removing the heater hoses, turbo pipe, engine brace, etc. Good thing I got to it in time before it ruptured.

I also replaced the turbo waste gates hoses as they they hardened in my 14 year old car and broke when I touched them. Since now I have access, I also adjusted the turbo waste gate to factory spec of 6.5 psi. They have drifted to 4.5 psi over the years. Now the car has much better acceleration kick and so much more fun to drive!

I used BMW blue coolant, which has the same Volvo coolant formulation. Many say the European coolant formulation will reduce localized boiling in turbo cars. I will see in the upcoming summer months.

Cheers

[weespoon]

I had a very difficult time getting the clips back in as well.

I second any one who mentions heat, as this is what finally worked for me.

Here is what worked for me.

1. Most important put O ring in grove in housing not on pipe.
2. Put something slick on O ring (coolant works).
3. Very carefully slide pipe in right orientation, not at an agle, so O ring doesn't get pinched.
4. Get pins in as much as you can, even 1/2 way was a good start.
5. Put coolant back in system.
6. Put down some rags to catch drips, run car and heat system, until it blows hot, even though dripping.
7. Turn off car, release pressure from under hood.
8. Apply a little pressure to pipes, and pins slid right in place, the expanding and contracting with the heat made it far easier to simply slide pin back in place.

[Jaz]

Is there a particular eye and eye turnbuckle u need to help getting the core pipeline all the way into heater core so can get the pins in

[KevinCollins]

For those still wondering about hitting the linkage, try pulling the heater out just a little and blocking it there, you will clear the linkage no problem.

The o-ring must snap into the plastic case, don't try to force it, you can but it is extra work, everything should snap into place. Just pushing one little corner of the o-ring into the notch in the case will get it started. Take a small screw driver and poke it in, there's a little notch where you can see it. Hope you greased everything before you put it together.

Order new clips when you order the core & o-rings, they are aluminum and they get scarred and don't got back in so easy. When you take the tubes off the core, similarly, be careful not to scar the tubes, so that it goes back together without forcing it. The clips are cheap compared to how much extra work it is to use the old ones. They are strictly a one-use item.