Upper Radiator hose leakage - help! This is driving me crazy!

[tbrumm]

So I replaced the upper radiator hose on my 1994 F350 a few weeks ago, because the old, original one was "weeping" at the radiator inlet. I also flushed the cooling system at that time. added new coolant and proper amount of DCA4. All was good for a few days and then i noticed the new hose weeping a bit by the radiator inlet. Ugh! Checked the worm drive clamp and tightened her up a bit. This thing continued to leak so I bought a constant tension hose clamp with the bellville spring washers. Took the hose off the inlet, and cleaned the inlet down to bare brass with scotchbrite so it was nice and shiny and clean. Hooked up hose and leaks worse than ever. Bought a new hose (gates), installed that, still leaks, even with a bit of sealant under the hose on the inlet. Never in all the years I have done my own repair work have I seen a hose leak like this. Usually they seal so well you can't hardly get them off! Anybody else have this problem or have any ideas? Of course, the hose only leaks when the cooling sytem is up to temp. and under pressure. Tried a new radiator cap too - still leaks. You can watch the coolant very slowly make a small bead out the end of the hose and then drip down to the top tank seam. Also, when I drain the coolant to drop the level down below the top tank, the coolant in the bucket has a foam head on kind of like a beer? Is that normal - I can't remember seeing that when draining coolant. I should mention that the truck has just over 66,000 original miles on it. I am not losing any coolant except from this hose leak. Thanks for any suggestions, Guys - I am pulling my hair out on this one!

 

[WhiskeyBottle2]

Boy that's a tough one...I just wonder if you aren't getting some exhaust gasses pumped into the radiator from the head?

 

[lindstromjd]

Or maybe the inlet is cracked just a hair...

 

[icanfixall]

Could be the neck at the radiater is no longer round or there is a split in the neck. Remove the hose and use a kitchen scotchbrite pad. Buff it all in the same direction. Then look for a line across the tiny scratches the pad made. If you see nothing buff the neck the other direction and look again. If there is a tiny crack it will show up. Often times heating it up with a torch will really show up the crack because the crack is a sharp edge and heat will make it glow hot. But be careful on the brass. Too much heat will melt the soldier.

 

[tbrumm]

Well, the inlet certianly looks okay. With it all cleaned up, I can see it pretty well. The inlet also appears to be round too and isn't deformed. I am about ready to "glue" the hose to the inlet somehow!

 

[tbrumm]

I had cleaned the inlet up with scotchbrite, but hadn't thought about the torch. That could be worth a shot.

 

[mobilemech]

I had cleaned the inlet up with scotchbrite, but hadn't thought about the torch. That could be worth a shot.

carefull with the torch, you don't want to unsolder the fitting.
do you have a picture of the hose installed and the leak, cause it may be the inlet leaking at the tank and running back to the hjose and dripping from there.

 

[hesutton]

I like a thin coating of RTV on the inner part of the hose where it contacts the rad inlet (or block for that matter). Slide on the hose and clamp it down good and tight. Leave it dry for a day and then fill. Not always...... but it usually keeps a great seal.

Heath

 

[dsltech83]

Aviation permatex is what I use to seal hoses. Learned that trick at the shop I worked at going through college. Old or new all hoses got sealed with that stuff.

 

[riotwarrior]

Aviation permatex is what I use to seal hoses. Learned that trick at the shop I worked at going through college. Old or new all hoses got sealed with that stuff.

Ya talking aviation form a gasket....AKA Elephant SNOT...ya I guess that would do the job....

On a side note...I was thinking about this in bed last night and I can try it on a rad here...a slight Slight ...very SLIGHT tweak with a tail pipe expander....just saying...maybe your neck is slightly out of round or crushed and that could be a problem?

I'll try it photo it and let ya know how it goes...

 

[RLDSL]

All the sealing on earth doesnt explain where the foaming is coming from. Sounds like you need to get ahold of a combustion gas leak detector kit from Napa or Snap On ( recomend this one , harder to get a false positive with the dual chamber) Follow directions carefully regarding lowering coolant level in rad. Put a piece of cardboard in front of rad to bring coolant up to temp and have it fully circulating before test. Also remove CDR and block it off to prevent gasses entering from places other than the head gasket on first test ( then run the test again with it in place to see if the intake manifold runners are leaking at teh gasket , small amount of pressure in the rad many times can be blowby entering the cooling system from the CDR via the intake runners, ez fix compared to a head gasket , if you do have to reset the intake valley pan, hit the intake runner surface with a few light coats of spray Hylomar to avoid the problem next time) For any of the tests, remember to let it stay on there longer. The instructions tend to favour testing for gas engines. The fluid isn't as sensitive as it could be for diesels, so just leave it on the rad neck for about a minute. Just make sure you dont suck coolant up in there ( this is where the snappy unit comes in handy , although Ive been using a napa one for years, just have to be a LOT more careful and end up dumping a batch and restarting once in a while) but so long as you dont contaminate it, you will not get a false positive no matter how long it's on there, if there's no gasses present, you can leave it on there for a half hour and it won't turn, but if there is, it will turn a yellow/green

 

[tbrumm]

I appreciate all the replies and suggestions, Guys! I knew the Oilburners Support System would not let me down. I cleaned up the radiator neck again, and cleaned up the hose. Put it back together again and brought her up to temp. So far so good! the drive in to work tomorrow will be the real test though. As far as the foam goes, thanks for instructive reply, RLDSL. With the rad cap off and the engine running, I see no bubbles in the coolant in the radiator, so it just doesn't look like it is foaming while in radiator. It makes some foam when I drain it from the radiator into a bucket sitting on the ground. I don't know, maybe splashing into the bucket makes it foam?? I should also mention that the coolant is pretty warm when I have drained it. I am just trying to think of the least painful possibility here. I hate to think that my Baby might have a leak! I will keep everybody posted. Thanks again! Todd

 

[tbrumm]

I had another thought about the foam in the drain bucket. When I put in new coolant about three months ago, I put in the yellow bottle Prestone I purchased form Wallyworld. Yeah, I know NOW that I shouldn't use that, but at the time I didn't think it mattered. It says it is low silicate. Anyway, I added the appropriate amount of DCA4 to bring it up to about a 2.5 on the test strip. Do you think maybe this coolant is foaming a bit becuase it doesn't belong in diesel? I am going to change it out for some Fleetcharge from Tractor Supply which Mel mentioned in another thread. I don't want to go with the Cat or Evans coolant right now. I really apreciate all the brainstorming here. Thanks!

 

[riotwarrior]

After many many flushes, including but not limited too, a complete system fill with diesel coolant, then a complete loss of coolant as the water pump failed. I then replaced my pump, and added water to test for leaks, running about a week and a half including a trip camping no issue.

Drained the system, added another 4 gallons of fresh coolant and then water. FIND LEAK IN RAD in a few days.

When I drained my radiator and block from lower hose ONLY....the coolant in the bucket got all foamy too, I wondered if it was any remaining flush material but I just didn't bleieve it after many rinses with water and a complete run with fresh coolant then water then coolant...NO couldn't be had to be something different in this purple Prestone Diesel coolant, was all I could come up with.

 

[WhiskeyBottle2]

The way I flush my system is by removing the t-stat and when actually removing the flush water and chemicals I also remove the block plugs and lower radiator hose. After the initial flushing I then use nothing but distilled water and flush again. Replace t-stat, tighten up block plugs etc...

I then refill using Fleetcharge and distilled water. I use 3 1/2" gallons of Fleetcharge which leaves me a 1/2" gallon for topping off when needed. I also finish off the fill with distilled water. Then...with the radiator cap OFF...I fire up the engine and let her run until my gauge shows normal operating temp...about 170 to 175 degrees ideling while occassionally squeezing the radiator hoses to try and get all the air out....I also make sure my overflow tank is full to the hot mark. Once I think all the air is out and engine is warm I cap the radiator...let her run for 5 more minutes and shut her off and let her cool down...After driving her for the next couple of days she will suck what she needs from the overflow tank back into the radiator while she cools down. If she sucks coolant down below the cool mark on the overflow tank I will top her off back to the cool mark. After a few days she is completely full and shouldn't have to add any more coolant to the overflow tank.

Finally, I pressure test the radiator cap...and do a leak down test to make sure I have no slow leaks anywhere...

That Fleetcharge is good stuff and that's all I use. After a while...if the dca's are low...I just add a few ounces of Pencool...I get my Fleetcharge from O'rielly's Auto...It is usually kept in the back room and cost's me $14.00 a gallon on average. As far as foam goes...I never get any...I suppose if any flushing chems get left behind there would be some...