1997 Volvo 850 GLT Radiator Hoses Preventative Maintenance?

[scot850]

I wrote a reply to this and posted it but once again it has disappeared for some reason?? Basically the guys have covered all the issues. Either leave it alone if it is not leaking, but if it keeps you up at night, then replace it but then do all the other parts too, hoses, thermostat, flush and new coolant. Water pump gets done with the timing belt.

Neil.

[moses3]

I wrote a reply to this and posted it but once again it has disappeared for some reason?? Basically the guys have covered all the issues. Either leave it alone if it is not leaking, but if it keeps you up at night, then replace it but then do all the other parts too, hoses, thermostat, flush and new coolant. Water pump gets done with the timing belt.

Neil.

Neil, yesterday I thought it was leaking, but on second inspection midday today, I think it's oil from an old leak, I will monitor.

[scot850]

The most common areas for leaks on the radiator are:

1) the top hose joint to the radiator - This can fracture and the top hose shear off (one of my cars did this). The reason for the failure was not the engine mounts but the original Volvo radiator has a brass liner tube in it presumably to strengthen a section that gets worked hard by the ending rocking back and forwards over the years and the top hose stresses that area at the mount. What happens is that liner detaches and works its' way out the tip hose outlet into the rubber hose weakening that area.
2) 2nd area is the joint seal between the end tanks and the aluminum fins at the joint eventually breaks down and starts weeping. Again this tends to happen at the same side (passenger/RHS) but I have heard of it on the passenger side as well, but usually near the bottom. The leak on the RHS is often higher up near the hose.
3) Third area is the seals on the oil coolers. If you have a turbo it can happen at both ends potentially. It will start weeping around the outlets and inlet of the pipes. I had this on one car, and a radiator shop was able to repair it by replacing the seals.

Then obviously there are simpler issues of hardened hoses not sealing when tightened (good quality clamps and hoses fixes that).

Like you said, best to clean the radiator as best you can and if necessary a sheet of cardboard under the radiator will maybe show residue of any missed leaks by leaving a witness damp mark.

Good Luck!

Neil.

[moses3]

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.

They're both easy, Robert DIY has videos for both on YouTube

[moses3]

In one of his videos, Robert DIY says you should replace all coolant hoses every 15 years or 150,000 miles to prevent catastrophic over heating. That's good enough for me.

[scot850]

Not sure where in the US you are, but a few words of caution!! The radiator is held in place either side behind the slam panel by a bolt either end of the radiator. These bolts are prone to rusting as they are exposed. Start soaking these now until you tackle the job daily with a good penetrating oil like PB Blaster, Liquid Wrench, Kroil etc, not WD-40.

After a few days try carefully to loosen the bolts a little at a time. Run them back and forwards in their threads to see if they will shift. Be warned the bolt heads are at the bottom and need to be accessed from there. The nuts are welded captured nuts and like to break loose. If they do, the only option is to cut the bolt heads off, or try and hold the nuts somehow like with beefy Vice Grips.

Good Luck!

Neil.

[moses3]

Not sure where in the US you are, but a few words of caution!! The radiator is held in place either side behind the slam panel by a bolt either end of the radiator. These bolts are prone to rusting as they are exposed. Start soaking these now until you tackle the job daily with a good penetrating oil like PB Blaster, Liquid Wrench, Kroil etc, not WD-40.

After a few days try carefully to loosen the bolts a little at a time. Run them back and forwards in their threads to see if they will shift. Be warned the bolt heads are at the bottom and need to be accessed from there. The nuts are welded captured nuts and like to break loose. If they do, the only option is to cut the bolt heads off, or try and hold the nuts somehow like with beefy Vice Grips.

Good Luck!

Neil.

Neil, did you mean to post that here?

[moses3]

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.

Fell apart when you touched it..... Are you referring to the plastic parts that go into the firewall? Those seem like they would be fragile after 25 years....

[WhatAmIDoing]

The plastic bits have been fine for me. The rubber hoses started to turn into a squishy brittle substance that I wouldn't call rubber.

[moses3]

The plastic bits have been fine for me. The rubber hoses started to turn into a squishy brittle substance that I wouldn't call rubber.

At how many miles