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antifreeze leak

November 26, 2016, 10:19:33 pm

Changed to new antifreeze a couple of months ago flushed real good new hoses and still having leaking problems at fittings good clamps , am I suppose to to put sealer at fittings or what? 

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Re: antifreeze leak

Reply #1 – November 26, 2016, 10:43:41 pm

Art,

Do you have the constant torque clamps (the ones with springs to compensate for temperature change?

They are better than standard clamps.  Make sure they are properly torqued.

And, my next step would be to add a second clamp to the leaking hose end.  And put the worm gear 180 degrees from the other clamp.  This is standard practice for the marine trade.

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Re: antifreeze leak

Reply #2 – November 27, 2016, 04:29:34 pm

Art,
I think I experienced the same thing.  Very small leak?  Just an occasional drip?  Noticed it in the morning when everything is at it's coldest?
I installed hoses in summer and saw these kind of leaks when cooler weather arrived.  I tightened the clamps a little more even though they already felt 100% tight and the leaks did stop.

I've recently worked on the cooling piping design for a locomotive.  The "best practice" there is to to use two constant tension (spring) clamps @ 180 deg like Brett has suggested.  But also to a T-Bolt style verse worm drive.  The worm drive can strip trying to apply enough pressure; thus Brett's warning for proper torque.  The T-Bolt style has a much finer pitch so not as much torque needs to be applied for the same clamping force (but the max torque on the nut still needs to be followed).  The downside is cost and the diameter range is much smaller (1/4" spread verse 1" for a worm drive) - so measure carefully.  Also, 2" seems to be the smallest constant torque T-Bolt available.  Smaller T-Bolts can be found but not with the constant torque feature.  My guess is most auto parts stores won't carry T-Bolts.  I have seen them at hydraulic hose shops.  There are plenty of sources online like Amazon and McMaster-Carr.

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Re: antifreeze leak

Reply #3 – November 27, 2016, 04:45:04 pm

When there is a raised surface on the male part--the one that goes in the hose--there is a recommended location for any hose clamp to prevent leakage and/or damage to components. Too far on and there is a void between the raised bead and the clamp that can fill with non-circulating fluid that decays. The hose can actually swell from pressure.
The clamp must be just inboard of the raised bead in order to function properly...1/16" to 1/8" max. This will cause the hose to press down on the raised bead in addition to under the clamp.

Just having the right clamp doesn't necessarily guarantee success. Proper application helps insure success.

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