Date: Sat, 18 May 2019 10:16:34 -0500
Reply-To: "Jim. Felder" <jim.felder@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Jim. Felder" <jim.felder@GMAIL.COM>
Subject: Re: Coolant Loss/Hose clamp tips?
In-Reply-To: <CACARJKpogHGCDYJsfF5Pz+nx-2zELt8qufx1W6bBT9PMYx8hGQ@mail.gmail.com>
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In my experience it doesn’t matter what type clamp you use—millions of cars that don’t leak have been made with both—as long as the condition of the hose rubber is good. If it isn’t, there is just not much you can do.
If you have cold leaks, it probably won’t hurt to tighten further. You can look at a hose where it is clamped and see when it is pinched too much, or not enough. There is an art to it. On a diesel system with plastic fuel lines I finally had to remove the clamps between the filter and injector because the clamps—any of them—distorted the line to the point of leaking air. No clamp, no leak. I would compare the plastic line to hardened rubber.
Jim
>
> On May 17, 2019 at 9:37 PM, <Alex MeVay (mailto:alex@mevay.org)> wrote:
>
>
>
> Hi All,
>
> I'm a little embarassed to be asking this question, but Friday on the
> list here is supposed to be a little more lighthearted, right?
>
> TLDR, can anyone share any tips on getting hose clamps to work
> reliably over the long term?
>
>
> My van has been drinking some coolant, maybe a pint every few thousand
> miles. This has been low on my list, as there haven't been any other
> concerning symptoms (i.e., head gasket leak). Occasionally I would
> find a few drips on the ground, trace it to a hose clamp, and snug it
> up. Other than that, the amount of loss seems so small that it
> evaporates before it leaves any evidence, making troubleshooting
> difficult.
>
> I recently got a loan-a-tool pressure tester from Autozone,
> pressurized the system to ~15psi, left it there for most of a day,
> pumping up as needed, hoping that with things cold, the drips would
> remain visible. I discovered little seeps/drips from NINE places.
>
> I am for sure a little gun-shy on tightening hose clamps, as I've been
> burned by low-quality aftermarket replacement plastic flanges for my
> I-4 that mush into oblivion under the tension and begin leaking. I've
> gradually been replacing these (and any barb couplers) with metal
> where possible, and swapping any notched hose clamps with the smooth
> kind.
>
> I tighten these "firmly" with a screwdriver-sized implement. Last
> time around, I marked the clamps so I could see if they backed off,
> but don't have any data there yet.
>
> I'm considering installing one of those stainless coolant tube
> replacement sets, but as I understand it, this adds a hose-clamp
> junction above the gas tank, where a drip will be a big pain to fix,
> so I want to make sure I figure this out first.
>
> So...
>
> Is there a torque recommendation for these clamps? Is it different
> for plastic or metal flanges?
>
> Do these leak due to insufficient initial torque, loosening over time,
> or plastic creep (in the hose or plastic flange)?
>
> Do the "pinch" style ones work any better?
>
> For high-risk locations (above the gas tank), what about some of those
> clamps with integrated spring to help maintain tension?
>
> Thoughts appreciated,
>
> Alex
>
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