Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks



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Joined: Apr 2013
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I’ve got a persistent leak on the lower radiator hose assembly on my ”˜40. It’s the CO4’s hose set that came with the metal elbow, 2 rubber GM script hoses and 4 clamps. The leak persists on the upper part of the elbow. I’ve tightened the clamps as far as they go. It still leaks.

Is there any fix besides replacement? I’m not so sure those vintage “correct” clamps are worth the leaks. I may replace the lower hose with the flexible ribbed lower radiator hose as seen on the NAPA site.

Why did GM use the metal elbow, 2 hoses, 4 clamp system?

Thanks,
Curt

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I'm all for replacement, BUT have you tried Permatex?
Putting the clamp fasteners 90 degrees apart might help.
Wilson


Wilson
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I’ll try moving the clamps 90 degrees. Makes sense.
Thanks Wilson.

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I always use a light coat of permatex on my hose connections which means you will have to drain radiator & take that connection apart to do that. Reason for 2 hose system was most likely due to flex hoses were not available back then ??

dick


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There have been some prior posts regarding the performance of the retro style hose clamps.

I finally had to replace mine. They just would not seal.

Apparently the reproduction clamps are not made of as thick a metal and are not quite as wide. So all you are doing when you really tighten them is distort the ears where the screw and nut meet on the clamps.

I am a big fan of the constant tension spring type hose clamps that are used on cars today. You never have to go back and retighten them like the worm gear clamps. I agree they can be a pain to install and remove.

I had to use a small amount of sealer on mine because the outside diameter of the ends of the metal pipe as well as the outlets for the water pump and radiator were pitted. One other trick to make those seal is to rebuild the surface with JB Weld and sand it smooth.


Rusty

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In a prior post on here someone suggested using the permatex and at first use the worm type clamp. After a few heat cycles and sometime, replace the clamp, with out disturbing the hose, with the old style clamp. Worked for me.

Dave

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Use some Indian Head shellac. That should hold it.

The fault is not likely to be in the clamps.

Good luck,

Charlie computer

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In addition to the above Ii think todays rubber hoses are not as soft as those used originally. With todays higher pressure cooling systems the hoses are reinforced more to withstand that pressure.


Steve D
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On my 41 since I am not going for something period correct I used the NAPA hose and had no issues. Had to cut one end to length but that was it. I did not try the period correct one as I am not building a show car and was looking to eliminate possible spots for a leak.


I have found that having an old car is a constant project that is never done. I think that is a good thing. Keeps me learning new things. Having two from different eras is just a form of higher education.
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Thanks for all the helpful suggestions.
Everyone has made some very good points.

Since it’s just an annoying drip type of leak, more of a seeping ooze, I’ll continue to tweak it here and there. Or, remove it, clean up the metal contact areas, apply some of that permatex goo, or Charlie’s Indian head shellac.

Thanks y’all,
Curt



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Some great info here that I hadn't thought about yet that will save me some pain. When I get to this point, I will consider some kind of sealer to bond the two rubber pieces of hose to the metal pipe...while they are still new and clean and can do it on the workbench until fully cured...


1938 Canadian Pontiac Business Coupe (aka a 1938 Chevy Coupe with Pontiac shaped front sheet metal - almost all Chevy!)
1975 4-speed L82 Vette

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