Re: radiator neck failure mode analysis.

[Andrew Duane USG/PE <duane@zk3.dec.com>]

Hairy green toads from Mars made David Kavanagh say:

> It happened to me!
> On the return leg of a Taco Bell run on Saturday night, my upper
> radiator hose slides off the radiator neck! I pull into a nearby plaza
> lot and find the upper hose hanging off and steam everwhere! I push
> it back on, and start to wonder why it came off. Then I remember the
> postings about this failure mode. I take if off and see the ring left
> inside the hose! I loosen the hose clamp and clamp the hose on the remainder
> of the neck, add water and drive home. 
> I have a used radiator from an 88 or 89 that I'll be putting in tonight.
> 
> So, about the failure mode...
> Is it just that the plastic gets brittle after a while and this happens
> to be the most stressed area? I noticed the crack happened right under
> the hose clamp. Does this mean that the extra pressure of the clamp
> is a contributor to failure? If this is true, It sounds like a good idea
> to clamp as close to the bump in the end of the neck as possible. This give
> you room to play if it fails on the road. I know I'll be carefull to 
> tighten the clamps gently as well! Also, on the replacement radiator,
> I noticed the plastic is thinner near the end of the neck. Does that mean
> it is better to clamp farther in?

The same thing happened to me last summer. Broke off right where the
hose clamp was.

I suspect you are right; the heat cycling and age makes the plastic
brittle, and the stress of the hose clamp is the extra nudge that
makes it break right there.

I clamped mine back on to the remaining pipe, and drove the car
fine for 2-3 weeks (until I got a new radiator).

The radiator installation was easy; I let Chris do it :-)
Actually, it doesn't look that hard. Just remove everything
that seems to be in the way (isn't much) and do it.


-- 

Andrew L. Duane (JOT-7)			duane@zk3.dec.com
Digital Equipment Corporation		(603)-884-1294
110 Spit Brook Road
M/S ZKO3-3/U14
Nashua, NH    03062-2698

Only my cat shares my opinions, and she's too psychotic to express it