1997 Volvo 850 GLT Radiator Hoses Preventative Maintenance?

moses3 · Post by **moses3** » 12 Apr 2023, 03:52

The car has 160,000 miles, should these hoses be replaced preventativly? They look original.

They look easy to do, and I figure at 25 years old, they must be near their end of life?

Someone also suggested replacing the thermostat?

Post by **abscate** » 12 Apr 2023, 04:24

More a philosophical question if you want to run the car in run to fail mode, or preventative maintenance mode.

This is determined by the tolerance for failures in use.

When my kids went to school 4 hours away, the cars got a lot of PM work like new cooling group parts.

My 99 Kat stays close to home and I have a tow dolly so I tend to run things to failure on that car.

If you are in a four season climate with little ozone, the OE hoses can easily 200k

Take a good luck at the hoses near the clamps for excessive bulging and nastiness. Share pictures if you want feedback

Post by **jreed** » 12 Apr 2023, 05:42

I replaced all the hoses on my '97 855 to reduce the chances of sudden coolant loss while out and about, potentially leading to engine failure.

Post by **hausmeister** » 12 Apr 2023, 05:50

For rubber hoses imo it is less the mileage, more the age and maybe heat cycles(?) that will kill them.
I have replaced all the coolant hoses on mine and if you plan to keep it I would also recommend to do it. It is not that difficult or expensive. And who knows how long these parts will be available. Worst condition of all on mine was the heater hose lines. Looked fine, but were crunchy to the touch.

hughiescho · Post by **hughiescho** » 12 Apr 2023, 06:48

I am enjoying the information shared here--thank you!

Moses3: How about replacing your radiator too?

Post by **abscate** » 12 Apr 2023, 06:55

The in between model of RTF and PM is you buy the new parts and store them in the car so you lessen the impact of a failure by having parts on hand, while squeezing every last penny of life out of your OE parts.

Your GLT turbo has some nasty, hard to replace small hoses serving the turbocharger that are cheap and hard to inspect, so replace those on either model, in your driveway/garage

moses3 · Post by **moses3** » 12 Apr 2023, 08:12

hausmeister wrote: ↑12 Apr 2023, 05:50 For rubber hoses imo it is less the mileage, more the age and maybe heat cycles(?) that will kill them.
I have replaced all the coolant hoses on mine and if you plan to keep it I would also recommend to do it. It is not that difficult or expensive. And who knows how long these parts will be available. Worst condition of all on mine was the heater hose lines. Looked fine, but were crunchy to the touch.

Heater hose lines, the ones that go between the fire wall to the heater core?

WhatAmIDoing · Post by **WhatAmIDoing** » 12 Apr 2023, 10:27

In my experience, the heater hoses will last forever as long as you don't touch them.

Inspect the hoses. If there are no bulges, cracking, or signs of seeping, then they are probably serviceable for a while longer ~200k. They are all easy to replace baring the coolant supply line that runs to the turbo. That requires some flexible fingers. Mine failed suddenly causing all my coolant to run out onto the driveway in about 5 seconds.

I've become a big fan of silicone hoses. They hold up better, are easier to work with, and seal up much better. It's been a while since I bought a kit, but they weren't much more expensive than rubber, and will likely last forever.

I for sure recommend the do88 silicone turbo coolant line kit and heater hose replacement kit. You won't have to worry about those leaking again.

As for availability, I recently needed to aquire a coolant overflow hose to the expansion tank and couldn't source a quality one, so good luck.

Lastly, preemptively replacing the thermostat can be opening a real can of worms. The 2 torx head fasters like to weld themselves to the aluminum housing. Periodically spray them down with penetrating oil, so when you need to replace it hopefully you won't have to drill and tap new threads.

454cid · Post by **454cid** » 12 Apr 2023, 11:16

The upper hose would be easy, but I'm not sure the lower hose is easy. I've never changed mine, but doesn't it snake around the back and is basically a blind install? Seems like I've heard that Volvo used a couple different hose designs, too.

That age/mileage is definitely getting up there for hoses, in my opinion. I'd be torn between wanting to keep a high quality original, and fearing that it might give up. The first thing to do would be to check for swelling at the ends.

If you're going to go the whole 9-yards, and flush the system, and change the thermostat, then inspecting the hoses internally might be an option, but I hate breaking those connections unless I really need to, as sometime they don't want to re-seal and/or clamps are never the same.

I probably wouldn't do the thermostat unless it needs it... unless maybe you want to get in there and make sure those screws aren't seizing. I have not had issue with them, but my cars are low mileage. I use anti-seize when reassembling.

moses3 · Post by **moses3** » 12 Apr 2023, 11:33

WhatAmIDoing wrote: ↑12 Apr 2023, 10:27 In my experience, the heater hoses will last forever as long as you don't touch them. Inspect the hoses. If there are no bulges, cracking, or signs of seeping, then they are probably serviceable for a while longer ~200k. They are all easy to replace baring the coolant supply line that runs to the turbo. That requires some flexible fingers. Mine failed suddenly causing all my coolant to run out onto the driveway in about 5 seconds.

I've become a big fan of silicone hoses. They hold up better, are easier to work with, and seal up much better. It's been a while since I bought a kit, but they weren't much more expensive than rubber, and will likely last forever.

I for sure recommend the do88 silicone turbo coolant line kit and heater hose replacement kit. You won't have to worry about those leaking again.

As for availability, I recently needed to aquire a coolant overflow hose to the expansion tank and couldn't source a quality one, so good luck.

Lastly, preemptively replacing the thermostat can be opening a real can of worms. The 2 torx head fasters like to weld themselves to the aluminum housing. Periodically spray them down with penetrating oil, so when you need to replace it hopefully you won't have to drill and tap new threads.

Kroil is good for screws /bolts that seize into aluminum.