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Lower radiator hose leak

Christopher1968

NAXJA Forum User
Location
san diego
OK just looking to see if anyone has had this same problem. Doing a cooling system rebuild, water pump, t-stat, upper hose, lower hose, heater hoses, heater valve and flush the block. All went fine then found a leak on the lower hose. Twist and wiggle the hose and the leak leaks more. Reinstalled old hose (figured it worked before), old and new clamps, same problem. New pump from NAPA and high grade constant torque clamps. Anyone had a problem with water pump lower necks? Just looking for similar problems. I am really fustrated. Pulling the pump again tommorrow and checking for a flat or disformed neck. Two hoses, four clamps and the problem won't go away. It has to be the pump, right? Any tricks to seating the lower hose? Maybe I am missing something simple. Throw me a tip or information. Thanks.
 
Over tightening the clamp can cut the hose right at the lip, hard to see until you take the hose off and bend it at the trouble spot. I've had quit a few lower hoses start to seep at the pump inlet, seems to be a trouble spot, reason unknown to me. Though this usually happens to corroded lower inlets more often than new ones.
Is it possible there is a crack in the inlet or the leak is running down from the top someplace and just showing up at the pump inlet? This is a typical spot for weep hole seeps to show up, even thermostat housing seeps to show up. It's really hard to see above the hose much, I've found a small welders mirror and flashlight can be helpful in tracking down seeps.
Using old hoses, I've coated the lower inlet with silicon (after cleaning and drying) slid the hose on and then tightened the clamp with good results. I've even removed the hose again without damage. Though this may be luck more than typical.
I also use silicon lubricant (plumbers lube) on most all of the hose nipples, this helps avoid wrinkles in the hose while tightening, especially on old stretched hoses.
When reusing old hoses you have to check that the inner and out layers haven't separated, this is fairly common.
 
Mine had a good bit of corrosion on the necks for both hoses- I went after it with sand paper and emery cloth, as it was pretty rough looking. How do the hose connections look?
 
Good tips guys. No need to "prep" the pump neck it is brand new. If I don't see any deformation on the neck then RTV will be the choice to seal the new hose. Yup, pulled the hose off and twisted, squeezed, bent and generally tortured the hose trying to see a nick. But overall, two different hoses and four different clamps and same rexults. Might even try gasket tack (similar to Indian Head). Seems like an oddball problem. Real fustrating as I have Terra Del Sol this weekend and would like to get some run time on the cooling system before touring the desert.
 
Good news, found the problem. The thermostat housing was cracked. New housing and things are great. Hovers just below 210 with spikes to 210 once in a while. I am so happy. I just have to work in better light.
 
One of the things I always do with my hoses is swab the inside 2" or so with Indian Head gasket cement, give it a couple of minutes a then put it on, I also never use a screwdriver to tighten the hose clamp, I use a 1/4" ratchet, seems to get it to the right spot, painful enough on the hand when you try to over tighten it.
I've also gotten to the point I actually like the spring style clamps, no guessing, hated them before. The factory hoses come with them already on there.
 
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