Volvo S70, V70, 850 Heater Core Replacement - Video

[songzunhuang]

great video wish I had found this forum a year ago. heater core and PCV service are next in line. Robert is a great contributor
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Yup, +1 on Robert! He saved me with regards to my core replacement.

Also, I ended up using silicon heater hoses. The OEM hoses I ordered turned out to be URO! Returned them and went on a frantic search when I came across a hose shop just south of me that services farm machinery. They sold me blue silicon hoses for $4 per foot. I used these along with the original metal ends from the old hose.

Anyway, in the end I ended up with a better setup. I should be good for a long time.

[cn90]

A quick announcement on Swedish Auto Parts heater cores. Do NOT use the two (2) O-rings that come with it.

- Just replaced the heater core using the ebay Swedish Auto Parts heater core ($39.95 shipping included).
- Boiled a pot of boiling water, added some DW soap, then dipped the HC in this hot water solution (I removed the foam first, may not be necessary). You can wash it in the DW too, but it takes too long b/c my DW cycle is 2-3h or something like that.
- Rinse it clean.

- Used the two (2) O-rings that came with the ebay HC. Refilled with coolant.
- When cold (not under pressure) it is fine. But once you run the car, the leak starts at the O-rings. Not much, but a drop here a drop there.
- So the advice of leaving the side plastic panel OUT after replacing the HC is dead on: after replacing the HC, you want to have access to this area for a week or so. This way you can monitor for any coolant leak.

- Now the local dealer wants $7.50/each for this O-ring (PN 3545586)! What a ripoff for an otherwise $3 part.

[cn90]

Also, a trick for those who are "lazy". On the passenger side, I didn't touch the glove box or underpanel.
I did it by feel. The pass side T25 screw (the screw that goes straight upward) is a bit tricky but you can do it blind.
This saves the time removing the underpanel, glovebox etc.

[850TurboTurtle]

1. Robert is my hero.
2. I hear you can gently blow air into the upper firewall coupler using a compressor with a variable blow attachment and a hose, to bubble most of the coolant out before you disconnect the passenger compartment hoses. Going to try it myself tomorrow.

[jreed]

I agree with that!
I changed our heater core a few months ago and I put a hose on one of the coupler ends and a little cup under the other end. I blew air through the hose a few times (just using lung power) to force more of the coolant in the core and lines out into the engine compartment. Some came out and it seemed to help but you will still want plastic bags, towels and a cup in the passenger compartment under the core when you loosen the screw holding the pipes, because some coolant will drip out... at least, that was my experience.

[abscate]

I ran my coolant out and replaced with water by flushing it for 15 minutes under idle first. SWMBO hates antifreeze smell so I go to extra trouble to keep it out of car. Of course, in retrospect, that would have been a way to keep my T5

The other morning, she backed out the NA and took the T5 because she had a biz trip up the Northway....

[lovallo]

Thanks for the great video!

I dont have anything leaking in the heater core area, I have steam coming through the vents into my cabin.

Does this imply that my radiator might be running too hot and I need some thermostat replacement as well? Does a radiator often run above the boiling temperature once open to atmospheric pressure?

Thanks!

[JimBee]

The steam is coming from a heater core leak. I just replaced mine for that reason. I hadn't driven the car since October. In February, I took it out on an errand and I felt steam HOT! coming from the vent. Returned to the car from the errand and all the windows were steamed.
Then it was obvious the heater core was leaking. A Volvo buddy and I changed out our cores one warmish day in February. No more steam.
I've done one before so I knew how to go about it. Those $39.00 cores do have a kind of sour milk odor for a few hours, but it goes away. Not to worry about it.
A couple of hints:
That straight up screw on the core box cn90 referred to can be hard to get if you're working blind. We stacked two tires/wheels on the ground just outside the doors to sit on (with a foam cushion on top). Then you can slither on your back into the foot well, ideally with a shop light so you can see what you're doing up there. Piece of cake. Going at that screw blind plan on a lot of frustration.
If you live near a Dollar Tree they carry HUGE ziploc bags (for sweater storage, etc) After you've drained about a gallon of antifreeze from the radiator, you'll still have some in the heater core and its lines unless you blow it out, like suggested above. Slip one of those ziploc bags around the core, box and all, then with the 4 screws out, remove the whole thing sitting in the bag. It's easiest to take it out the passenger side so you don't need to fight the pedals or shift cables. You don't need to remove the glove box to do that, only the bolster panel and side kick panel by the console. Having a helper is useful. You can pull it loose from the driver's footwell and push it across to your helper on the passenger side, keeping the whole core assembly right in the bag. Works great. You won't spill a drop. And those bags are stiff enough that you can grab one corner and pour what's in the bag back into your coolant bottle.
You might want to spray the new o-rings with silicone. I use it on all o-rings. Needed? I don't know. But I got no leaks from the beginning.

[abscate]

Adding to some VRD database here, pseudo random points

I had a bad core leak that I mitigated by running with the reservoir cap loose to keep pressure out of the system. This was in winter, and I would not do this on highway or in heat.

When my leak got too bad, I would lose heat from the climate system. This means you are about 4 liters low on coolant. Don’t do this.

I bypassed the core with Gates 5/8 hose and junk store hose clamps for a week. Picture attached.

If you disconnect the two hoses at the firewall you can push coolant out of the core and just leave water. Which evaporates. The core holds little volume, like 250 ml or so. It’s high flow which gets you the heat.

[ZionXIX]

+1 for the worlds longest heater core bypass hose.