1995 850T wagon – Backyard fix for radiator neck?

[Seamonster]

Hi all,

The plastic radiator “neck” of my 1995 850T wagon has broken. Standard practice says that the whole radiator should be replaced. However, my car has approx. 200k miles on it and I don’t have money coming out my ears, so I’m contemplating a non-standard fix, which might not need to last for more than a few years. Looking for advice and comment.

Approximately 1/4” of the plastic neck remains (the full normal length is about 1.5”). The break was clean. I’m thinking I could find ABS tubing, or something similar, with outer diameter roughly the same as the neck’s inner diameter, to epoxy into the remaining bit of neck. That piece could be a stub just long enough to fit into an outer coupling (again, like ABS), with an outer diameter that would fit into the existing hose and clamp.

My thought is that constricting the flow through the slightly narrower ABS diameter briefly – for about a linear inch – would still be within functional tolerance of the radiator; that the cross section might be reduced by about 5% in area, so the radiator should still work fine except perhaps in the most extreme of conditions.

Is this idea nuts? A few more specific questions:

Does anyone know what is the inner diameter of the neck? (The car is at my mechanic’s, but if I were to show up there within the next few days with a piece of ABS and coupling to fit, he’d let me try it, at least, before insisting that the whole radiator be replaced.)

Is ABS robust enough to withstand heat/pressure, or is there some other off-the-shelf piping that would be better? Maybe some thin-walled steel pipe from a plumbing supply place?

What sort of epoxy would be best? Is there some special high-heat formulation? Would standard Bondo work well enough? Or what epoxy would bond best to the radiator material?

Any other ideas?

Bonus question: Why is this crucial piece made of crappy plastic in the first place?

Thanks,
Kraig

[abscate]

Is the neck the hose joint on the upper right part of the engine?

I would do this.

Buy:
a new radiator hose to thermostat.
JB weld epoxy
Two hose clamps



Clean the end of the break so that is fairly square, not too critical. Go to a junkyard or plead here for one if our junkyard dogs to deliver the neck cut off a junker..

Now break out the JB weld. Coat the surface of the new nose lightly with JB, work it into the hose leaving your 1/4 space. This might be tough and you might need to even cut off the flange on the new nose to work it in. Now JB weld the radiator 1/4 nose piece, pop on the radiator hose and clamp with two clamps, lightly...let the JB make the seal.

Allow to set for 24 hours. Use regular JB weld, not quick set.

If your current hose is in good shape you could use it, but if it blows you obviously can't replace it.

[tryingbe]

If you attempt this, I guarantee you the neck will break away while you're traveling on highspeed on a freeway when the pressure and temperature would be the highest in your radiator.

$67 isn't much for a radiator.
http://www.ebay.com/itm/93-97-Volvo-850 ... e3&vxp=mtr

Why the radiator is plastic? Because you won't pay the $500 for an all aluminum radiator.
http://www.eurosporttuning.com/aluminum ... 94-98.html

[renns]

I'm all for saving money, but in this case I don't think it makes much sense trying any repair unless you're stranded. My thought: grab a used rad from the wreckers. It can't cost much more than $20, and you might spend near that on various epoxies and supplies trying your repair schemes. Just my .02...

[Ozark Lee]

I've tried them all over the years and with a plastic tank radiator I have had zero long term success. The best I have ever done is buy another month or so and slow the leak down a bit.

...Lee

[cn90]

Don't ever fix a broken radiator neck, been there done that, it is a TRUE waste of time.

If your budget is tight, go for junkyard radiator.
Or look around on ebay.

[Scholz]

If you're truly set on attempting this, get a true ABS chemical adhesive such as Weld-On #2354.

[volvooh]

agree with all above. spend the $67 for a new radiator and give yourself piece of mind. Doing a repair like that is a timebomb.

[Seamonster]

Thanks for all the brain cycles, guys. Looks like I'm gonna have to go with the majority and have my mechanic do it. I was sorely tempted to test my (and your) ingenuity -- and now I'll get soaked -- but I'm planning to do some traveling soon, and the path of least resistance is not to be messing with it myself.

Now that I've posted this, the guy with the perfect can't-lose solution can feel free to chime in.

[abscate]

If you are going to cruise long distances, a jury rig isn't good.

If a 67 buck part isn't in your repair budget you need to get out of Volvo. These are cars designed got people who want to drive a Rolls Royce on a Caddy budget.