Water Pump Hardware 48 Flathead
 

Hello,
What is the size, thread and length, for the bolts that are used to install the water pumps on a 1948 V8? Is stainless hardware recommended for the bolt inside the water pump? Thanks.

Re: Water Pump Hardware 48 Flathead
 

Yes to stainless for the bolt inside the pump and don't forget some anti-seize on it as well. Not sure of the length but I'm sure someone will be able to provide that info.

Re: Water Pump Hardware 48 Flathead
 

I've never had a bolt in the water pump not come out, and none were stainless. Anti seize is a good idea, you should be running a corrosion inhibitor of some type in the cooling system.
Martin.

Re: Water Pump Hardware 48 Flathead
 

The water pump stainless steel bolts are a cure for a problem that doesn't exist.

Re: Water Pump Hardware 48 Flathead
 

evidently 42 merc you have never tried to remove a bolt inside the pump with the head rusted nearly off, a $1 stainless steel bolt is worth a lot more than that to save hours of fustration trying to remove a rusted bolt

Re: Water Pump Hardware 48 Flathead
 

Maybe it was just a bad dream, or more like a nightmare, when I tried to get those inner water pump bolts out of a 59ab engine that I planned to have rebuilt. The 9/16" hex heads had rusted down to something close to a 1/2" hex. I drove a metric size socket on to what was left of the hex, heated the area inside the pump around the bolts and the heads snapped off of both bolts. This allowed me to get the pumps off, and by luck there was just enough of the bolt shank left to grip with vise grip pliers. I heated that area around the bolts a couple times and applied some candle wax. I was never so happy when they began threading out. After that, its been stainless steel bolts with anti seize on threads for any of those internal water pump bolts that I install

Re: Water Pump Hardware 48 Flathead
 

Someone sells a stainless bolt kit for the water pumps, Speedway, or MACs? Sorry, the CRS is getting to me.

Re: Water Pump Hardware 48 Flathead
 

John and Mr coast,
From your experience the bolt can be an issue it seems. As I said, I haven't had the displeasure, so could go either way. Thanks for input.
I do still think though, if your running an antifreeze/summer coolant (which contains a corrosion inhibitor) and change it as specified by its manufacturer) and anti seize on threads, you can use a regular bolt, and it won't be an issue.
Stainless bolts, normally A2 are not good mounting hardware, they gall up and seize quite easily if not cover with anti seize, and snap or round off easily.
There maybe decent quality stainless bolts, not A2 sold for the purpose, that would be better.
I font think it's a needed thing with good coolant.
Martin.

Re: Water Pump Hardware 48 Flathead
 

Back to the original question. I believe 3/8 course bolt 1-1/14 long. Walt

Re: Water Pump Hardware 48 Flathead
 

Be careful about the length if you are replacing all the water pump bolts, they are not standard length and some will bottom out. ..B.

Re: Water Pump Hardware 48 Flathead
 

Walt, is that a typo and you were typing 1-1/4?

Re: Water Pump Hardware 48 Flathead
 

Scooder, you are right, stainless wont take as much torque as a steel bolt, but the difference is slight, steel bolt 3/8 x 16 is 31#,stainless steel 3/8 by 16 is #29

Re: Water Pump Hardware 48 Flathead
 

3/8-16 and I believe the correct length is 7/8". In some cases a 1" bolt bottoms out before tightening. G.M.

Re: Water Pump Hardware 48 Flathead
 

Thanks everyone for the replies, I will be attempting removal of the old pumps (in about a week) and already see rusted bolts inside the water cavity. I will replace the hardware, and be sure to not use bolts that are too long. Thanks for the great advice!

Re: Water Pump Hardware 48 Flathead
 

Make sure you use a 6 point socket so you don't round the heads. G.M.

Re: Water Pump Hardware 48 Flathead
 

Whooop, 1-1/14 is find of wead, TYPO, just use some common sense, make sure they don't bottom out. Walt

Re: Water Pump Hardware 48 Flathead
 

And if the 6-point socket feels loose, use a smaller metric 6-point socket even if you have to hammer it on.

Lonnie

Re: Water Pump Hardware 48 Flathead
 

God its a stupid idea having those bolts inside a water jacket ..
But as dumb as having the crank seal on the inside on a Y block..

Re: Water Pump Hardware 48 Flathead
 

The pump mounting bolt in side the water jacket broke when starting to loosen it. When changing out a water pump one side at a time, can the engine be supported with a jack under the oil pan? I prefer not to have to pull the engine. Thanks.

Re: Water Pump Hardware 48 Flathead
 

Yes it can. Put a board between the pan and the jack.