‘99 S70 AWD Coolant Leak 9186487 9186849 Topic is solved

OberonXIV · Post by **OberonXIV** » 28 Dec 2025, 17:16

Hey all,

When I was driving home on the highway, Ol’ Girl here threw a smokeshow and gave me the red coolant light. There was a massive puddle of coolant when I got it towed, and now that I have some time I decided to try and diagnose it. The leak is coming from the drivers side, and it flows like a fountain. Importantly, the oil isn’t milky so I’m ruling out a head gasket for now. After checking all the hoses I can see, my intuition was pointing to the coolant line on the turbo, but it seems like it’s coming from somewhere else. Anyone have any idea where to even start? Attached are photos of the leak.

Post by **scot850** » 28 Dec 2025, 17:30

Check the cabin coolant hoses at the bulkhead and the bulkhead fittings for splits. Also check the turbo hoses and lastly the pipes along the back of the engine on the bulkhead side.

One last possibility is the lower coolant hose from the side/back (depending on year) to the lower side of the radiator which may have split.

Neil.

OberonXIV · Post by **OberonXIV** » 28 Dec 2025, 17:53

Thanks for the assistance Neil. I’ll check all the mentioned and report back once I have a chance to get to it again. The angle gear was being a PITA and I couldn’t get a good look at the turbo lines.

On a side note, I think this photo is pretty poetic.

Post by **abscate** » 28 Dec 2025, 19:04

Is that the dreamy 421 Silver S70 AWD?

Turbo hoses ( two of them ) or the heater hoses to bulkhead. From the position amd flow, I would guess heater hoses. Visible ftom up top

OberonXIV · Post by **OberonXIV** » 29 Dec 2025, 20:17

Success! Thank you abscate and Neil for the assistance. The leak was coming from this fitting here:

Tracing the hose back leads to here:

Does anyone know the measurement of the hose off the top of their head? Also, is there supposed to be a clamp or something here?

Post by **scot850** » 29 Dec 2025, 20:22

There have been various threads about doing away with the connections at the bulkhead and making your own hoses. Those are crimps and they do start to leak with heat, age and time.

Neil.

Post by **Chuck W** » 29 Dec 2025, 21:15

I have had good luck with replacing the heater hoses with the silicone upgrades (On the original ends) and replacing the o-rings on the bulkhead fittings.

We have had zero problems with them. She's got 65K on hers since 2018. Mine have roughly 25K since 2020.

Post by **abscate** » 30 Dec 2025, 03:01

You want to be gentle removing those heater hoses. Official procedure, squeeze the yellow tabs and pull forward

Crack…goes the $150 bulkhead fitting and now are under the dash for 2.5 hours of work

On edit…that fitting is now $389 ouch. At least you get the $60 orings for free….

Gently twist the fitting 1/8-1/16 of a turn (~ 0.4 radians if your metric) spraying in silicone spray until it is turning nicely on the 4 sealing o rings inside. Then it will ease out without breaking the plastic, offering prayers to Thor and Odin the whole way.
Hose clamps on the othe end , probably need replacing with the Volvo ones or oetikers

The new part is expensive And I wouldn’t use any aftermarket here. $100 each fir hose , $25 for 1-2 year garbage parts

You can cut off those swage fittings and replace with 5/8 gates heater hose.I’ve got a 100 foot roll in supply I can send pieces if you want or hit the local NApA for that. You have to zip tie the routed hoses to prevent chafe and wear, the toting is tight with a lot of hot stuff nearby

https://www.fcpeuro.com/Volvo-parts/V70 ... ic&b=Wagon

You can see the complicated oring set up in that link

Pm model, do both hoses
Run to fail, just one.

Post by **abscate** » 30 Dec 2025, 04:00

The elimination option is nicely documented in the Volvo Repair Database here

https://www.matthewsvolvosite.com/heate ... ion-wpics/

My experience is you can use 3/4 PEX fittings if you put the fittings on the hard line, push the hose over the bulge, the sneak the PEX clamp onto hose, again with some silicone lube. Those clamp real nice and tight

OberonXIV · Post by **OberonXIV** » 02 Jan 2026, 10:46

Thanks for all the help. I was able to get the job done, but I had to wait until after the holiday season to get it sorted. The biggest PITA was the crimps on the copper elbows. I tried it with a hacksaw first, but eventually just took it slow with a dremel. Replaced the yellow connectors and o-rings with an ipd set (Sidenote: their office in Portland, OR is quite nice) and she’s up and running again.