Volvo OEM Radiator Dissected

Post by **mecheng** » 10 Sep 2015, 11:27

I finally got around to dissecting a failed Volvo OEM rad, it leaked through the crimp to the plastic cap.
I wanted to see in particular what the oil/coolant cooler looks like and how it is designed.

It is good to see that the wall thickness is quite good, and for the oil/trans cooler it has fins inside the fluid passage and outside the fluid passage so there is good heat trasfer.
If you didn't know, you can tighten the cooler fitings with a hex socket, I'm guessing it is a tappered fit to ensure a tight seal as there is no o-ring or any compound on the thread.

You can see the plastic end caps are crimped to the radiator which is a weak spot for all Rads, they should apply some kind of sealant on the outside if the crimp fails over time, the sealant will come into play. Or better yet, lose the plastic end caps and make the aluminum caps feasible in large scale production.

The Rad had 230,000km and the coolant was a weird color when I purchased the car so it probably wasn't changed often. Even considering this, still there is no corrosion to be found, and I think the risk of the water and oil mixing is low when evaluating its construction. But, it will leak eventually. In my case, it was a slow drip. Enjoy the pics

dux02v70 · Post by **dux02v70** » 10 Sep 2015, 12:59

Thanks for taking the time to hack it apart and share. Radiator looks new inside. Pretty surprising.

Post by **dosbricks** » 10 Sep 2015, 20:18

That's really interesting. I had no idea how the oil cooler was constructed. Thanks for sharing.

Post by **erikv11** » 10 Sep 2015, 20:57

So bottom line, are the oil cooler and the trans cooler the same construction or not? I can't tell if you took them both out or just one of them. If they are not the same, then which one is shown in the pics?

Very insightful to see the pics, thanks for showing this!

1ezliving4ume · Post by **1ezliving4ume** » 11 Sep 2015, 10:42

very cool thank you! I now understand how coolant and trans fluid could mix. The coolant is actually around the trans cooler and the oil cooler.

Post by **mecheng** » 12 Sep 2015, 04:45

I agree pretty interesting to see. Shown is the oil cooler, for cost purposes I would imagine both are the same. I saved my blade so I can cut a used oil filter open. That was a huge mess but also interesting.

The oem material and or the volvo coolant even when really old is impressive considering how there is zero corrosion

Post by **abscate** » 12 Sep 2015, 05:29

That is really cool. thanks for sharing that.

Im guessing if you make the end caps metal the cost of manufacture soars and replacements will be 600 USD, which we would all bitch about.

Post by **cn90** » 01 Dec 2017, 23:23

Hi mecheng,

I know this is an old post but I have a question re cooler port b/c I have the leak exactly where the port joins the plastic tank area.

- How is the cooler port sealed?

- Is the rubber seal on the INSIDE or OUTSIDE of the radiator? The reason I ask is that:
---> If the seal is INSIDE, I won't remove the port for fear of the seal falling down and that is the end of this radiator.
---> If the seal is OUTSIDE, I can play with it.

Thanks!

Post by **abscate** » 02 Dec 2017, 03:40

It doesn't look like there is any seal on those ports. It looks like you get sealing in the oil cooler with either compound or tape, and coolant sealing by the oil cooler butting up to the plastic radiator boss.

I would use Teflon tape to reassemble if I tool this apart, but not too much. Too much tension of metal into plastic will crack

Post by **ZionXIX** » 02 Dec 2017, 05:09

Does anyone know if those really nice do88 radiators use this same style transmission and oil coolers? Ive been thinking about investing in one and never changing the radiator again.