P80 air distributor heater core o-rings 3545586 confusion

Post by **abscate** » 22 Oct 2021, 04:56

There is a little bit of confusion in Volvo webstore. These-rings are used in three places on the heater core

1 one on each pipe, in compression between core and pipes

B. INTERNAL O-ring sealing pipe to plastic junction inside car…one or two per pipe?

iii. At the firewall connection, where I believe the fitment is, from front of car ( amd so loading order)
Fat spacer, oring, thin spacer, oring

The diagrams in Volvo webstore, for air distribution box, conflict a bit.

Post by **abscate** » 22 Oct 2021, 04:57

Also , number 9 , a t25? Torx screw is loaded from the rear, not front of car as depicted

Post by **erikv11** » 22 Oct 2021, 08:44

abscate wrote: ↑22 Oct 2021, 04:57 Also , number 9 , a t25? Torx screw is loaded from the rear, not front of car as depicted

The torx screw number 9 indeed loads from the rear of the car.

The o-rings and spacers, it's been too long since I took one apart. Hopefully it stays that way. But if you search it is definitely in the fora.

EDIT: I had it wrong, fixed the text to match reality.

Post by **abscate** » 22 Oct 2021, 09:40

Hmmm. My 1999 the Torx head is rearward and the 1999 I just did was the same

The threads are in the black plastic manifold , Professor?

Post by **erikv11** » 22 Oct 2021, 17:38

Yes, I refer to the solo screw down at the bottom of the heater core. And you are right - I will edit above to avoid confusing others!

Post by **abscate** » 13 Jul 2022, 04:40

Bumped by the Serbian Huskies….

Post by **hausmeister** » 13 Jul 2022, 09:05

Let me share the diagram I got with the set I ordered from skandix
You need 2 per hose, and additional ones for the heater core and internal connection if you replace those. I did not take apart the internals so can't help you there

Btw, make sure you pay attention to that plastic ring... It seems there are different clips, and with the longer clips you can't use the ring, the drawing confused me but in essence that is the reason behind the 2 different drawings as far as I can tell.
I first tried to leave the fat ring on, but it wouldn't fit. upon removing it I realized the differences in the old&new clips and in the drawing.

(edited with attachment instead of link)

: IMG_20211231_152233.jpg (98.66 KiB) Viewed 1873 times

Post by **abscate** » 05 May 2023, 02:10

Sizes on the firewall heater o-rings measured by scot850…

greg850r · Post by **greg850r** » 06 May 2023, 08:26

I just posted this in a different thread above but it seems relevant here:

You can eliminate the whole mess by cutting the top half off the aluminum pipes coming out of the heater core and slipping heater hose over the pipes. Double clamps are advisable here because the lack of a flange on the end of the aluminum pipe where you cut it off makes leaks more likely.

Take the black double hole plastic fitting that sits in the firewall and remove material until the outer diameter of the heater hoses slip fit snugly through the holes. Then remove the stock heater hoses from the engine.

The result is a hose running directly from the clamp at the engine through the firewall to the clamps on the heater core pipes. This eliminates 25 year old plastic fittings and a bunch of o-rings that in my opinion are too expensive and too failure prone.

Just my 2 cents.

Post by **erikv11** » 06 May 2023, 09:09

greg850r wrote: ↑06 May 2023, 08:26 I just posted this in a different thread above but it seems relevant here:

You can eliminate the whole mess by cutting the top half off the aluminum pipes coming out of the heater core and slipping heater hose over the pipes. Double clamps are advisable here because the lack of a flange on the end of the aluminum pipe where you cut it off makes leaks more likely.

Take the black double hole plastic fitting that sits in the firewall and remove material until the outer diameter of the heater hoses slip fit snugly through the holes. Then remove the stock heater hoses from the engine.

The result is a hose running directly from the clamp at the engine through the firewall to the clamps on the heater core pipes. This eliminates 25 year old plastic fittings and a bunch of o-rings that in my opinion are too expensive and too failure prone.

Just my 2 cents.

I used to advocate for this method and used it for a while but gave it up about 10 years ago. It works great but engine fumes can still get into the cabin, and you must choose the grade and length of heater hose carefully to avoid kinking. The hose setup also stresses the junction with the heater core and can cause failure there. So yes it works but in the end I decided replacing the whole coupler is a better long term solution if you want something more worry-free.