940 Coolant System Hoses??

[Steve 940]

Hi

Think I would like to do a bit of preventative maintenance, and replacing all the coolant system hoses on the 28 yr old girl.

No evidence seen of any issues per se, temp gauge steady as a rock at midpoint, no need to top up and did 800 miles in June whilst on holiday down to Cornwall. Just when poking around checking fluids weekly, the rubber hoses do just feel a tad weak.

Haven't tried seeing if FRF can supply genuine Volvo hoses yet, but I have seen silicone sets from DO88, definitely in black though😀

Would look to do a full flush and replace stat, hopefully with genuine Volvo one at same time.

If the piggy bank allows, would it be worth replacing rad?? Seen a few posts about plastic sides splitting??

Oh also, what do you use coolant wise, I have genuine Volvo concentrate, but should I use rain water, distilled, deionised or just tap.

Cheers
Steve

[griston64]

Originally Posted by Steve 940

Hi

Think I would like to do a bit of preventative maintenance, and replacing all the coolant system hoses on the 28 yr old girl.

No evidence seen of any issues per se, temp gauge steady as a rock at midpoint, no need to top up and did 800 miles in June whilst on holiday down to Cornwall. Just when poking around checking fluids weekly, the rubber hoses do just feel a tad weak.

Haven't tried seeing if FRF can supply genuine Volvo hoses yet, but I have seen silicone sets from DO88, definitely in black though😀

Would look to do a full flush and replace stat, hopefully with genuine Volvo one at same time.

If the piggy bank allows, would it be worth replacing rad?? Seen a few posts about plastic sides splitting??

Oh also, what do you use coolant wise, I have genuine Volvo concentrate, but should I use rain water, distilled, deionised or just tap.

Cheers
Steve

The genuine new Volvo coolant isn't really compatible with Redblock engines now so I would go for either Comma Super Coldmaster or Comma G48. Mix 50/50 with deionised water NOT TAP WATER

All the coolant hoses are still available from FRF and I would say are better than the silicon ones. Also check the oil cooler hoses if your car is a turbo as they often get overlooked

I would give it a good back flush and change the stat at the same time. Worth checking the rad as they can also go on the stubs which are also plastic. A new Nissens rad is only about £100 so not that expensive. An upgrade would be an all aluminium one which vary from about £200 up to about £350.

[Forrest]

Might be worth a look at this thread. I recently wrote up my thoughts on coolant there.

https://www.volvoforums.org.uk/showthread.php?t=328065

As for hoses, you might find the silicone ones harder and less easy to work with than the soft rubber originals. I did when I replaced my turbo intake (air) hose with a DO88 one.

Also don’t forget the oil cooler and heater hoses. These are the ones that are more likely to leak and cause you problems than the big, obvious radiator hoses. And it might be a good time to replace the jubilee clips too. They don’t last forever. Check the quantity and sizes against the originals and consider stainless steel replacements.

If you replace all the hoses and clips with new then check the tightness of the clips again after a few hundred miles. I’ve known them start to leak as the clip beds into the new rubber.

[Steve 940]

Thanks for the info Mark & Forrest, much appreciated.

Will go for the genuine Volvo hoses then, and also add on the oil cooler hoses.

Interesting about coolant, pity as I nearly have a full 4l bottle, but if the new stuff isn’t great with red block then not worth using when doing all the hose replacement.

Cheers
Steve

[griston64]

Originally Posted by Steve 940

Thanks for the info Mark & Forrest, much appreciated.

Will go for the genuine Volvo hoses then, and also add on the oil cooler hoses.

Interesting about coolant, pity as I nearly have a full 4l bottle, but if the new stuff isn’t great with red block then not worth using when doing all the hose replacement.

Cheers
Steve

I also have an unopened 4l bottle in my garage which I bought before this info came up I suspect it would probably be ok as it's not full red OAT stuff. I would rather stick to old fashioned EG in a Redblock though as that's what they were designed for.

Also meant to mention your header tank as the bottom connection on that can corrode and mine fell apart when I last did a coolant change

Bet you wished you hadn't started now as this is getting more expensive by the minute

[Steve 940]

Hi Mark

Many thanks for that, the Volvo coolant is green/blue so I guess perhaps ok, but if I’m doing the hoses a few more quid will be needed from the piggy bank 😀

Will add on reservoir and new cap to parts list!!

Cheers
Steve

[griston64]

Originally Posted by Steve 940

Hi Mark

Many thanks for that, the Volvo coolant is green/blue so I guess perhaps ok, but if I’m doing the hoses a few more quid will be needed from the piggy bank 😀

Will add on reservoir and new cap to parts list!!

Cheers
Steve

Can't beat a nice new shiny header tank

[jpliddy]

Originally Posted by Forrest

Might be worth a look at this thread. I recently wrote up my thoughts on coolant there.

https://www.volvoforums.org.uk/showthread.php?t=328065

As for hoses, you might find the silicone ones harder and less easy to work with than the soft rubber originals. I did when I replaced my turbo intake (air) hose with a DO88 one.

Also don’t forget the oil cooler and heater hoses. These are the ones that are more likely to leak and cause you problems than the big, obvious radiator hoses. And it might be a good time to replace the jubilee clips too. They don’t last forever. Check the quantity and sizes against the originals and consider stainless steel replacements.

If you replace all the hoses and clips with new then check the tightness of the clips again after a few hundred miles. I’ve known them start to leak as the clip beds into the new rubber.

himark im using the blue green volvo coolant for last 23 years ,have volvo changed the spec but kept it the same colour blue green which seems odd to me
plus your coolant resivor broke with old age they seem very tough i have a spare second hand one too
regards jim

[griston64]

Originally Posted by jpliddy

himark im using the blue green volvo coolant for last 23 years ,have volvo changed the spec but kept it the same colour blue green which seems odd to me
plus your coolant resivor broke with old age they seem very tough i have a spare second hand one too
regards jim

I was told they changed it Jim. Others on here will probably be able to inform you the exact details

That one was a spare second hand one that I got off 940 that I broke. It looked ok but it was the metal sleeve that corroded and then it just started crumbling away. As I'm intending to keep the 940 I thought it was worth getting new for £30

[Forrest]

The debate on coolant types is probably endless. It seems to centre around whether OAT fails to protect or even actively erodes brass/solder components. There are not many brass/solder components in a 940 cooling system. However, sometimes the heater matrix is; and the heater matrix is the number one PITA to replace on these cars.

I have always assumed that because Volvo formerly recommended G48 (HOAT) and since 2015 have been recommending G64 (PSi-OAT) that the G48 would be better in an older Volvo. However, if you look up the data sheets on the Glysantin website the results of corrosion tests are much better with the newer G64 coolant, including on solder and brass. Furthermore, the safety data sheets (separate documents) list 2-ethylhexanoic acid as an ingredient of G48 and not of G64. It is this acid that is thought to be bad for solder/brass.

So who knows? I guess, if you can find it, original IAT coolant is likely to be a fairly safe bet but it will need changing more frequently than the more modern stuff. Maybe something like this:

https://www.mannol.de/products/antif...ol-coolant-g11