Packard Forum Index » Pre-War (1899-1942)

I was replacing the mechanical fuel pump on my 1940 120 this winter and all of a sudden I noticed anti freeze was leaking from the front of the car. I can't imagine how the leak could be related to my removal and replacement of the fuel pump, but I am open to any theory that might link the two?

It was too cold until now to get it out in the light of day to try to determine where the water was coming from. I assumed that maybe the radiator had sprung a leak, but upon closer inspection it appears to be dripping from the left front portion of the engine below where the generator is mounted. It's running out at a pretty fast drip. Are there any frost plugs in this vicinity that might have popped loose or any port to the cooling system that might have been loosened; we had an unseasonable cold winter with temps below 0 in WV. Anything else besides the water pump at the front of the engine that could be the source of this leak? I have felt around the water pump and can see no moisture coming from where it is mounted. I have also checked the upper and lower hoses at each end and they appear to be dry.

Don't think there is a core plug directly behind the generator but probably one directly above it. There is a drain plug about generator level but it is closer to starter -- although if the car is at an incline, leakage could be running toward the front.

The water pump has the two gaskets with the large flat steel cover and back plate between. Several places there that could have a leak where coolant would run down behind the pump and toward the generator.

Dan, my 39 120 started leaking at the same point this winter while I was working on the generator. The problem was the bolts around the water pump. You might check them to make sure that they are all tight. I suspect that is your problem area. I'd fill the radiator and watch it to see if you get some leaks, both with the engine off, and with it running.

Dan and Dave. Thank you so much for your replies. I will check much more closely the areas you have suggested. I may have to get some mirrors, because there is not much room to feel around in the front of the engine, and even less space to see what is going on. I'll make sure that all the water pump bolts are snugged up.

If in fact the leak is from a water pump bolt, I don't recommend just tightening them as some (all?) of the bolts go thru into the water jacket. I'd remove the bolts, coat the threads with gasket shellac or hardening Permatex, and reinstalling. Also, at least on the later pumps, one or more of the bosses on the pump face will have a machined recess - that's for a flat copper washer to seal the bolt head.

Easiest way to service the pump bolts is to first remove the fan - just 4 bolts. When reinstalling the fan, first loosely thread in a short stud to hang the fan in place and align the holes for the other bolts. Then remove the stud and install the last bolt.

I have now had time to tear into this problem and have removed the fan and pulley, only to discover that the pump shaft seal has failed and that is where it was leaking from. Time for a new/rebuilt water pump. I now recall reading somewhere that the most common signs that you need a new water pump are 1. when it begins to leak or 2. when it begins to squeal. I'll order a new one today.