Upper radiator hose leaking

W

wrndln

Well-known member
I installed a new set of radiator hoses on my car with a newly rebuilt engine. The lower 2 hoses installed just fine and had no leaks. The upper hose is another story. Both the end at the radiator and the end at the gooseneck leaked. I have new clamps and new hoses. The radiator inlet looks fine. It is a Berg radiator restoration. The gooseneck looks so so. The gooseneck has some minor pitting at the hose end, but not bad. Should the clamp go over the raised area on the gooseneck and radiator inlet or on the flat area inside the raised area? I am now tying to use a little grease to try to seal the joints. Does anyone have any suggestions on how to seal the hose joints?
Thanks for any help.
Rusty Nelson
 
make sure they go over the raised area....I found with new hoses that you have to install them and warm the engine up and then re tighen them again and you should have no more leaks!
 
Spray the inside and the outside of the hose (especially the outside) with Silicone spray lubricant (by Gunk). Available at most any auto parts store. If you are using original style hose clamps they need to be able to slide smoothly around the hose as they are tightened down. The original types tend to dig into the rubber under the adjuster. This causes a tunnel to form under it and the more you tighten it the bigger the tunnel and the more it will leak. Also check that the tab that is suppose to slide is cupped up so that it will not dig into the hose.

Tom Endy
 
First, the clamp should be position on the flat area next to the rib.

Tom makes a very good point. I haven't installed repro hoses in 25+ years so I forgot that some of those hoses a junk without a suitable reinforcement within the rubber. Consequently the rubber can stretch and displace as Tom described.
 
I have found that many of the new repro upper hoses are shorter than spec and don't leave enough room to properly overlap on both ends.
 
Talking about radiators, I would like to ask if there is any good advice that I need to know about filling a radiator. I just pour water\coolant innto it until it is about an inch from the top of the overflow tube, but will the engine have to be running when I fill the radiator? thanks
 
NO not running and start by filling it until you can see it, I use and many of us just clear clean water. I also add anti rust for the system. Drive it, chances are you will loose some and that is FINE.,. your radiator and engine will determine what you need. If you are not overheating you are fine.. That is all there is too it.. good luck
 
This afternoon I took some bearing grease and coated the inside of the ends of the top hose that was leaking. I had tightened, retightened hose clamps and moved the clamps around many times with no success before use a little grease. The grease seems to stop the leak. I don't know if it is a permanent fix of just temporary. Has anyone used grease to "seal" a hose? I don't think the grease will damage the hoses and I don't believe the grease will clog the radiator as I didn't use very much. Maybe there is a better way, if so please let me know.
Rusty Nelson
 
I have been known to use RTV in the same way. Just swipe a little inside the hose and tighten, give it a few minutes and fill.
 
I agree with Tom Endy's solution and description of the cause of leaky hose/clamps. Use silicon, not grease. Petroleum products are not a friend of rubber, they will degrade the rubber.
 
Permatex #2 inside the hose allows it to slip (same as Tom Endy's silicone spray) when the clamp is tightened. Also many of the old necks are dented, or rust pited which the Permatex will seal. Never had a leak using it on a radiator hose.
 
I had an original top cast outlet that had a bad mismatch at the casting parting line. I had to smooth it out with my Dremel to stop the dripping.
 
My truck is not a points car, and after trying my best to get things to stop leaking, finally went to T-clamp type hose clamps (from Jegs) and that (along with the grease/silicone/permatex or whatever) stopped the leaks.
 
I have to admit, it has to be a pretty bad leak to cause a radiator hose to leak on a non-pressureized system.
 
You must log in or register to reply here.
Back
Top