Heater Core Firewall Junction/Coupler bypass - DIY write-up

[theWIFES_S70]

Hey everyone, do we have any figures or statistics on how well the heater core firewall junction/coupler bypass has turned out for folks? It seems to make so much sense to me... Just wondering.

[polskamafia mjl]

Ya, it works 100% of the time. You're just removing the brittle plastic coupler and replacing it with heater hose.

[theWIFES_S70]

Sounds good to me! Thanks polskamafia mjl!

[bugs11]

Worked for me, did this mod last winter. FWIW I replaced the last "old" section of hose in the coolant system on my 850, the upper reservoir return, with Volvo OEM this past weekend. Pricey little piece of pre-formed hose, but it needed to be replaced.

[j-dawg]

Hey everyone, do we have any figures or statistics on how well the heater core firewall junction/coupler bypass has turned out for folks? It seems to make so much sense to me... Just wondering.

Probably 10k on my bypass, and it's working great.

Everything else on the car has fallen apart.

[cn90]

Hey everyone, do we have any figures or statistics on how well the heater core firewall junction/coupler bypass has turned out for folks? It seems to make so much sense to me... Just wondering.

Look at my post DIY right before your post above.
It works perfectly and the cost was peanuts.

[theWIFES_S70]

Hey everyone, do we have any figures or statistics on how well the heater core firewall junction/coupler bypass has turned out for folks? It seems to make so much sense to me... Just wondering.

Look at my post DIY right before your post above.
It works perfectly and the cost was peanuts.

Oh man, I forgot to order the Volvo OEM o-rings! (3545586) Thanks for that heads up!

[bugs11]

I should of mentioned I sourced the heater hose locally. Long story short, I bypassed the heater core when I replaced my head gasket last fall because the firewall junction leaked when I plugged in the new heater core hoses. I took the old heater core fitting to local auto parts stores until I found a decent heater hose that fit snuggley. I think I paid about $5 for three feet of hose. I also didn't drain my coolant when I did the hack. I took a couple of wine bottle corks and whittled them into plugs that fit the heater core hose. Then I removed one end of the bypass hose, plugged the bypass hose, held my thumb over the fitting from the engine and then quickley shoved the fitting into the new hose sticking out though the fire wall. I lost a little coolant, maybe 4-6 oz., but it was a lot easier than draining the system.

[theWIFES_S70]

Everything else on the car has fallen apart.

Man, what a life we've chosen for ourselves, huh?

[theWIFES_S70]

I should of mentioned I sourced the heater hose locally. Long story short, I bypassed the heater core when I replaced my head gasket last fall because the firewall junction leaked when I plugged in the new heater core hoses. I took the old heater core fitting to local auto parts stores until I found a decent heater hose that fit snuggley. I think I paid about $5 for three feet of hose. I also didn't drain my coolant when I did the hack. I took a couple of wine bottle corks and whittled them into plugs that fit the heater core hose. Then I removed one end of the bypass hose, plugged the bypass hose, held my thumb over the fitting from the engine and then quickley shoved the fitting into the new hose sticking out though the fire wall. I lost a little coolant, maybe 4-6 oz., but it was a lot easier than draining the system.

Thanks bugs11, I ordered a roll of 6 feet of Gates hose from Amazon. I think it was 9 bucks. It certainly looks and feels like strong hose. Of course I'll throw up my pictures after I get it done. I have so many corks lying around... I would do this, except I am going to replace ALL my hoses, they're all bulbous! (Like I mentioned in another post, I really do not want to drain this system again...) I am going to keep that wine cork trick in mind though. I like it!