'99 V70 Heater Core Replacement

[cn90]

One nice thing about doing the whole enchilada (HC, cut the pipes, run heater hoses ---> metal elbows ---> heater hoses ---> engine block):

- While the heater hoses are disconnected from the firewall, pour some water into one of the firewall outlets to flush coolant from the HC. Once this is done, get a hose and blow some air through the outlet. This way your HC replacement job is very clean.

[JimBee]

While we're getting creative on better prepping for the HC replacement, why not disconnect the hoses from the engine, leave them connected to the firewall, drain any coolant from them on the engine side, blow through one while catching what comes out through the other. Fill one hose with water, blow through, repeat. No coolant to deal with inside the footwell

[abscate]

Check under both your carpet and underlay before you go to a lot of effort to stop coolant spills. Check both front and back seats. I had about a gallon of coolant accumulated under this when I did my core.

Evan...I would wash it with the foam attached and inspect when dry. As a chemist, I would go for time over dishwasher agitation, though. Make up a suds rich mix of hot water and dunk the core in it for a few days to let the soap works it's magic. Stir it up to suds each day so you know the oil hasn't overwhelmed the soap.

You can get the new bulkhead connector from (vendors) for under 50 bucks...that's an option over the heater hose labour.....you get all new connections. The heater hose trick will save you money over the OEM Volvo hoses of course. On a turbo car, it's so tight in there I decided I wanted the fitted parts.

[E Showell]

Steve - I a already have a spare bulkhead connector.

[abscate]

I send you good karma for your repair!!

[E Showell]

New core is in thanks to my brother's help. We opted for a different approach than what might be considered typical. I was too lazy to remove the air guide to drain the radiator, but I have a very steep (15% grade) driveway. We put ramps on the high end of the driveway and had the front of the car facing downhill while I backed it up onto the ramps.

With the radiator effectively the lowest point in the cooling system, we put our plastic bags down and went to work. We lost the amount of coolant in the core, but I don't think more than that since the expansion tank remained full throughout the procedure.

Took a test ride to check for leaks and test the core and all seemed good. We've buttoned her up and I'll check the coolant level in the morning, but I am still over the min. level in the expansion tank.

There was ever so slight leakage around the old core o-rings from the coolant pipe junction and there was evidence of coolant seepage (again very slight) out of the top of the core where the tubes/fins are molded into the plastic. I'm guessing I could have gotten away with running the existing core for another year or so before the leakage was so bad that it absolutely had to be changed.

I ended up soaking the Estonian core for about 10 hours in a bucket of hot water with dishwashing liquid. I rinsed carefully and did not notice any untoward odors on our test, but the long term experience must be verified.

Thanks to Robert for his heater core replacement video. I watched it again as a refresher since I hadn't done the job in a few years. Total cost $48. (I did not replace the heater hoses in the engine bay and hope I will not come to regret that decision. I also did not replace the bulkhead coupler.)

[abscate]

Bravo Zulu!! You need heat this time of year!

[j-dawg]

New core is in thanks to my brother's help. We opted for a different approach than what might be considered typical. I was too lazy to remove the air guide to drain the radiator, but I have a very steep (15% grade) driveway. We put ramps on the high end of the driveway and had the front of the car facing downhill while I backed it up onto the ramps.

that's mad smart. sounds kinda scary to work on/in though.

[E Showell]

Parking brake on, car in park and chocks on both front wheels. Not bad to work on at all. I can't take credit for the positioning, it was my brother's idea. He's good with stuff like that.

[E Showell]

Apparently, the multi-hour soak with dishwashing soap and nearly boiling water was insufficient to eliminate the industrial cutting oil/spent firecracker smell from the core. Hoping it goes away with time. The wife says it is hard on the respiratory system.