Lower radiator hose weeping coolant at water pump

[ChryslerCruiser]

Last summer I replaced the lower radiator hose, and cleaned the water pump inlet, because the lower hose was looking really frail.

Now I have a very very slow leak at that spot. It might almost be too much to call it a leak, but I can see that it has leaked just enough to see that it was not 'coolant tight" and dried in place.

Is it a faulty hose clamp? I might have had it ever so slightly not perpendicular to the direction of the hose...

Water pump inlet corrosion? (there was some white corrosion to clean off after getting the old hose out, as I remember I cleaned the neck up with steel wool before installing the new hose)

What are your thoughts, or am I just being OCD about this?

 

[M_Body_Coupe]

No OCD here, if it leaks, it leaks!

My first thought was to ask how badly was the pump inlet corroded? So even with you having cleaned it up, there is no guarantee that whatever corrosion that has already happened wasn't bad enough for the hose to not be able to seal-up the divids in the casting.

I've never heard of a fix for this...maybe some kind of epoxy might work? Not a terribly hot part to start off with. I suspect though it might be just a simpler and certainly longer-lasting fix to replace the water pump.

Hmm...so back to the OCD point: how bad is that leak? LOL

 

[ChryslerCruiser]

I can not say I remember what the pump inlet looked like after I cleaned it up... I remember a white dusty scale coming off, and I suspect it was pitted some but unsure. . .

I guess the thing to do is pull it back apart, and inspect with a critical eye.. The hose clamp may be suspect as well, it looks excellent, but if it is not providing the pressure, then there is the problem right there.

 

[Mikes5thAve]

Are you sure it's the hose and not the wheeping hole at the bottom of the water pump snout?

Usually tightening up the clamps a bit more stops leaks. If its badly corroded you can clean it off with sand paper or a small wire brush. If it keeps it up you can try smearing some silicone sealer on the pump before putting the hose on. Sometimes new clamps help but when they're that size they are pretty good at keeping their round.

 

[Aspen500]

Just one thing, if the clamp is tightened TOO tight, it can cause a leak also. Plus, screw clamps don't provide constant pressure. When cold they are looser and as things expand with heat, it tightens up. That's why factory tends to use spring clamps instead. More than you really wanted to know, LOL.

I see it all the time at work where there's a light anti-freeze crust at some hose connections without an actual leak. More like very slight seepage. If it shows signs of traveling down the hose, then it's a leak, or of course if it's actually wet with coolant.

 

[ChryslerCruiser]

just one thing, if the clamp is tightened TOO tight, it can cause a leak also. Plus, screw clamps don't provide constant pressure. When cold they are looser and as things expand with heat, it tightens up. That's why factory tends to use spring clamps instead. More than you really wanted to know, LOL.

I see it all the time at work where there's a light anti-freeze crust at some hose connections without an actual leak. More like very slight seepage. If it shows signs of traveling down the hose, then it's a leak, or of course if it's actually wet with coolant.

Thanks Aspen,

No, not more than I wanted to know. Had no idea there was such a thing as a spring clamp... OR that there is such a thing as too tight (within reason)

I will inspect the bottom of the hose and decide if it is actually a leak, and then decide what to do about it all.

 

[Aspen500]

Some spring clamps are flat, others are wire type. There are other types of clamps also but, spring is the most common. Even the old "tower" clamps that Ford and GM used, while technically are screw clamps, they also hold tension. Pretty much a one use deal though. Mopar used the wire type for years. Nowdays, every make uses a flat band spring clamp. Rule of thumb on screw clamps is to tighten them until the band is flush with the rubber of the hose. If too tight, it might cut the hose and actually can lose tension after a number of hot/cold cycles. There are special hose clamp pliers for the band clamps and also the wire type.

Couple examples:

 

[Aspen500]

One type that will not leak or seep are the heat shrink style. I have them on my upper radiator hose. Obviously only one time use. To remove you cut the band and put a new one on.

 

[ChryslerCruiser]

Never hear, or seen of a heat shrink hose clamp until now.. what a great idea!

 

[69-]

If the water pump inlet is fray by corrosion, replace the water pump. Had to do that on '79 360 and replaced the timing chain while at it. It's just a couple bolts more

 

[LSM360]

How old is your water pump? And if it was replaced last time with a standard parts store one I wouldn't be surprised if it's corroded enough around the inlet to leak. Cheap junk from those stores. If it were me I'd see if clamp is easily snugged a little and if not after ensuring that's is where leak is from and not running down from elsewhere, I'd replace pump and hose (again). I would not go with a parts store pump. They may carry lifetime warranty but who wants to go through the labor again?! I'd get a Milodon or I believe GMB is supposed to be another quality brand. Again, that's just me. I don't play around trying to fix things like water pumps and chance it.

 

[LSM360]

On a side note, dang Aspen500 that BB and a/c looks good in there!!!

 

[Aspen500]

Thanks LSM!

GMB is OK although quality can be hit and miss it seems. At work I've noticed Carquest/Advance Auto Parts pumps for the 5.3 GM are GMB. Usually they're fine but we also have had a few premature failures. I'd trust a Milodon without hesitation though.

 

[LSM360]

Last one I replaced was on my '79 Power Wagon recently and I went with a Milodon (didn't have any paint dang it)

 

[BudW]

I'm jealous - that has one of the very good small diameter yet tall air cleaners (which is too tall for a FMJ). Those are hard to find.

I recommend to everyone to make sure all underhood parts are painted or plated. It is so much easier to clean, rust/corrosion will generally never be an issue, and in the case of the water pump (for example) an extra coating of engine paint at the gasket area is like an extra seal.
I like to use a bit of cardboard (or something) when spraying that last coat of paint to prevent overspray on engine.

I have removed radiator hoses before and found, extra thick layers of corrosion between the hose and aluminum (at pump or at thermostat housing).
To make sure you are leak free, you need to remove all signs of that corrosion - and that is no easy job. Filing or sand blasting is about the only two methods I know of. Filing works great at the thermostat flange gasket.
If you do any filing or sand blasting, the critical follow up is (again) to give it a good cleaning afterwards then a shot of paint.

Paint is the "missing element" to prevent corrosion!
BudW

 

[ChryslerCruiser]

I'm jealous - that has one of the very good small diameter yet tall air cleaners (which is too tall for a FMJ). Those are hard to find.

Paint is the "missing element" to prevent corrosion!
BudW

What is the application for those small diameter air cleaners? 2bbl or 4bbl? I may have overlooked one of those bottoms at the salvage yard, and I bet it is still there!

AND

Bud, I am appreciating your insight on how to clean up the radiator hose inlet. I will try again on cleaning it, and will paint it as well, before changing the coolant this fall.

 

[BudW]

What is the application for those small diameter air cleaners? 2bbl or 4bbl?

They make a 2 and a 4-bbl version. The lid is the same as most all other 2-bbl air cleaners.
The application is HD 1/2 ton and most 3/4-1 ton pickups (only). I hadn't seen one on a Van before. I think the years is (I think) early to late '70's.

I think his is a 4-bbl because the carburetor base is wide and it appears the fuel line attaches in the rear (but could be mistaken).

Most 4-bbl air cleaners are wider. On a pickup, there is plenty of space above the engine, so they went up.

 

[LSM360]

The one in my pic above is factory 360-4bbl on my 1979 Power Wagon. Bud you are not mistaken (no surprise there!).