48 Mercury water pump torque specs..

[SmoothFourty]

Greetings,

While I await my two rebuilt water pumps, checking on the torque specs for tightening the water pump bolts..
Thank you..

[V8 Bob]

I generally use new grade 5 bolts on non-critical parts, and stay with recommended torque values, which would be 25-30 ft/lbs using 3/8"x16 bolts, depending on aluminum or cast iron parts.

[1942deluxe]

From VanPelt's website 23-28ft/lbs, so right in there with V8 Bob's recommendation. There is a chart under service tips with torque values listed. I printed it off and saved it during my 59AB build. Very handy. Website is vanpeltsales.com .

[tubman]

And if all else fails, there are charts on the internet that give recommended torque specs by bolt size, grade, thread pitch, and material. They will get you very close.

[ford38v8]

Ford assemblyline men, shade tree mechanics, and dealership servicemen worldwide have, after their first 2 or 3 engines, discovered that they had become bionic and developed built-in torque wrenches into their wrists. 🧐

[aussie merc]

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hey dont forget to use stainless bolts on the one inside the intake [be carefull and check the grading] as some ssteel bolts are super soft and and dont forget the never seize as you will need to remove them in the distant future

[SmoothFourty]

Thank you One and All,,
Removed both Water Pumps - had Skip rebuild both.
Ordered new motor mounts, SS bolts kits from DC.
Just finished installing both pumps .. I'm torquing to 25ft Lbs..
A few more small items to button up before I refill radiator..
Thank you all one more time !
THANKS ,
Regards,
jim

[V8 Bob]

Just make sure those bolts are at least grade 5, or they will simply stretch with 25 Ft/lbs of torque.

[nellis003]

I know this is an older thread, but I had a relevant question...

Should the amount of torque relate to the bolt, or the gasket material? My concern is that if I use a harder metal bolt and torque it to that spec, am I crushing the gasket or stressing the cast iron too much?

I may be overthinking it because I'm used to cork valve cover and oil pan gaskets, but thought it would be good to ask here.

Thanks,
Nick

[rockfla]

My $.02 worth. FIRST, I take a piece of 3/8 X 3" Aluminum flat bar that I got from one of my Machinist and I wrap some machinist cloth around it and sand the face of the head where the water pump mounts to see just how "flat" the surface is. IF need be I dress that with a flat machinist file, then some 400, 600 then either 800 or 1000 grit sand paper. Its best to start and know that you have a good "Flat" surface and are getting "FULL" face contact with your gasket. Once that is accomplished THEN a little bit of Permatex skim on the face of the water pump and head and you can bet, the lower end of the torque spectrum will be ALL that is needed for a good, tight, proper seal and not over stress any of the components.


ALSO the above torque "range" quoted will depend on IF the bolt is torqued "dry" or with some form of thread lube. SO keep that in mind as well AS a lubed fastener will require less torque than dry!!!


ALSO as another aside, I "just" did a rebuild on a 1935 with stock Aluminum heads following the Flattening of the head surface and I torqued those bolts (A307's/NOT Grd 5's with the mill marks sanded off and painted) to 12 Fts pounds. NO leaks at all. I have run it through three heat cycles up to 180 coolant temp and not one leak or drip!!!!