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

Does anyone know if the 37 water pump for the 8cyl is interchangeable with the newer style with the permanent seal. I have replaced the packing 2 times now and it seems OK for about 100 miles and then starts to leak again. Any information or advice how to repack the original pump or point out something that I am missing would be appreciated.

You might check with Kanter. A few years back when I needed a 356 pump they had a repro that would fit many engines used over several pre 51 years but I don't remember which engines or how far back. When talking with one of their Packard guys he said that particular pump was able to fit the different engines because the differentiating factor between pumps listed in parts manuals was the fan hub diameter and how far it was pressed onto the shaft. They had the bare pump repro'd and pressed the hub on in house before shipping to the customer. If you have the senior engine then probably out of luck but if yours is a variation of the 245, 282 and 356 block maybe worth a call.

I don't think the 1937 110 and 120 pump will interchange with the '38 and later ones with the modern type seal. Kanter has new ones for the '37 for sale. I put one on my '37 120 and it is working well a year later and after several thousand miles. A pump with a bad shaft or worn bushings will leak persistently mo matter how carefully you pack and adjust it.
They will also leak air into the system at higher engine speeds and aerate the coolant which can can cause the radiator to overflow or actually boil. If you can find a kit for your water pump, new bushings, a new shaft, and new packing will usually get one working well. I rebuilt one from a kit, with no special tools, and I expect it will work just fine. The new unit I got from Kanter last summer looks identical to the original and is made of cast iron.

Thanks for the quick replies guys. I will be carrying water everywhere I go. I dont want to give up the summer driving and shows but will be doing it in the fall.

Be aware that a leaky water pump can leak air into the coolant at higher engine speeds. This can cause problems with the radiator overflowing, as if it was boiling, even if it isn't actually boiling. In addition, corrosion will be accelerated and steam pockets and local overheating, especially around exhaust valve seats, can occur. The pump can leak air IN when the engine is running, even if it doesn't leak water out when the engine is stopped. I'd replace or repair the pump now, rather than risk problems on the road .... and perhaps cracking a valve seat or two. The pump, fan, and pulley can be removed and replaced as a unit. Removing the right inner fender panel will give much better access to the radiator drain valve and to the lower radiator hose clamps. The panel is not very difficult to remove and replace.

You mention repacking the pump and it being good for about a 100 miles. I’m not sure how much it’s leaking, When it starts leaking again, have you tried just tightening the packing nut a 1/4 or 1/2 turn? I wonder if the new packing just “settled in” a bit and just needs the packing nut tightened slightly.

I would loosen the fan belt and check for any indication of loose bushings. The bushings may wear out of round due to the pull of the fan belt, so look for ANY wobble in any direction. If you can feel any slack in the bushings when working a fan blade forward and back by hand, the bushings are probably too loose to use. I tried several times to pack a pump with worn bushings, to no avail. After a few tens of miles, at most, it was leaking again. A pump with good bushings and a shaft in good condition will not leak if properly packed and adjusted. As noted, an adjustment or two may be needed immediately after re-packing, and it's a good idea to run the fan belt a little on the loose side for a hundred miles or so with with a new or rebuilt pump. The packing nut is not to be tightened, but only just snugged up. Tight packing can conceal loose bushings, so loosen the packing nut a little when checking for loose bushings. NEVER run the engine without water or other coolant in the system, unless you take the fan belt off. Doing so will burn out the packing.

Worn bushings will allow the fan to wobble slightly forward and back at the blade tips, and may allow the entire fan to move straight forward and back for a fraction of an inch. Test with the packing nut backed off a little and the fan belt slacked off.

A leaking pump will also tend to wash oil out of the shaft bushings, which will speed up wear.

I will only be doing short trips and local car shows over the summer and attack the pump problem in the fall.
Thanks for all the advice.

Personally, I wouldn't risk it.