I am pretty sure this has been covered before but I keep developing a coolant leak at my water pump where my lower radiator hose goes on. I use the original style tower top hose clamps as it is a concourse vehicle. (70 El Camino SS 396) I replaced the hose clamp, lower rad hose, and even cleaned off all the crud and paint where the hose goes onto the water pump. This darn leak keeps coming back about every two months or so. Is there anything I can do to fix this permanantly??? Should I use some teflon paste sealer that you put on the threads of bolts that go into water jackets???? Should I use some permatex sealer on the inside of the hose before I clamp it down??? Any help would be greatly appreciated as I am getting tired of wiping down the engine compartment due to the antifreeze flying around.

Thanks,

brian

Just FYI which you may already know.

I don't know how many times I've thought the lower hose was leaking only to find out it was coming from the water pump weep hole and running down and dripping off the hose.

Otherwise you must have a bad hose or a bad water pump.

Dean,

The coolant is getting past the clamp. The weep hole area on the water pump is perfectly dry and it is a rebuilt water pump. The lower radiator hose is also brand new repro. I think what might be happening is the imperfections in the casting of the water pump which gets slid into the lower rad hose is not making a perfectly good seal, thus when pressure builds up, pushes it past the tower top hose clamp.

Is there some type of sealant that I could use??

I always put sealent on the bolts that hold down the water pump. The bolts do go into the water jacket. Try the black (can't get off) permatex. It works well

In that case Brian, if it were me, I would coat the outside of the water pump hose spud with black Permatex "Form A Gasket".
Of course the drawback is getting the hose off later.

Dean,

Are you talking about the black RTV silicone or the other tacky stuff that comes in a bottle with a brush?

Here's what I do: take a half-round file and smooth away the casting flash and/or parting line. Then some abrasive cloth to smooth it even moer if you are really compulsively meticulous. Be sure there are no scratches, gouges, or cracks. The tiniest opening will seep/weep/leak. You just have to make sure the surface is smooth, and even. Doesn't kave to be perfectly round; just smooth and even. Casting flash can cut or gouge the hose. Again; the tiniest opening will leak pressurized fluid. Sealant is unecessary and undesirable since you may want to remove the hose someday and reinstall it. Reagular worm-drive clamp will be OK as long as the mating surfaces are smooth and even. Use small socket to tighten clamp, but don't overtighten. As mentioned above may actually be aleak from water pump seal. If i suspect the hose has cuts or damage I just stick a new one on. Hat messing with stuff like this.

My $0.02

No it's not either one, it comes in a small tube and called "form a gasket" - very dark brown in color.
Like I said it will glue the hose to the pump so that it will have to be cut off when it's time for a new hose but it will not leak.

I assume you've already checked the pump spud's surface for any rough spots like jj'65 mentioned because like he said, you really shouldn't need any sealer.

Ok, well..... I got one leak solved and another one formed. (or so it seems). The lower rad hose is sealing nice and tight with a new tower top clamp installed. Now I just noticed a small drip coming from the back of the pump plate which was not there prior to fixing the lower rad hose. Would you believe that none of my local auto parts stores have this item???? Anyway, necessity being the mother of invention and knowing I can remove the back plate without removing the whole water pump, I did the next best thing. I picked up a roll of gasket material so I can trace the back plate and cut out a new gasket. Probably even make more than one to have handy since no one locally seems to carry it. I will let everyone know tomorrow how I make out with this idea as it should work. A little RTV silicone and a roll of gasket material should do the trick.

told ya :D

Originally posted by Dean:
Just FYI which you may already know.

I don't know how many times I've thought the lower hose was leaking only to find out it was coming from the water pump weep hole and running down and dripping off the hose.

Otherwise you must have a bad hose or a bad water pump.

Dean, the water pump gasket was not leaking prior to me fixing the lower rad hose. After I got the lower rad hose fixed and sealed, I then saw a drip coming from the one lower left side of the water pump which was the opposite area where it was leaking initially. After sealing up the water pump gasket and reinstalling the by pass hose, the by pass hose now started leaking. I readjusted the clamps and now (knock on wood) it is leak free.