Coolant seeping from the head bolts

R

roadstar

Member
Ok I fix one thing and something else pops us. Sure glad we have message boards these days:D

So I changed from the stock cast iron heads on my 21 stud engine in my 37 pickup to the factory aluminum heads.

I used a coper clad gasket that was recomended. Sprayed copper gasket sealer on both sides, Also recomended.

I used a A/N washer under the head bolt as not to dig into the softer than cast aluminum head, also recomended.

Torqued the head to 45 lbs in three increment as per advise here on the Ford Barn.

Started up and things seemed ok. Let it cool and noticed a drip from one of the head bolts. I just tightened it some and it stopped leaking.

Next day I went out and noticed a few more were dripping slightly. So I started the engine and simply tightend them till they stopped leaking.

At this point I know I am over the recomended torque setting.

Should I have used some type of sealer on the studs or nuts. I did use thread sealer on 4 of the studs that had come out when I dissasembled the cast heads. But not on all the nuts when I put the new heads on.

Good news is it runs great with the factory ford aluminum heads and intake and looks great too.
 
The leaks will eventually stop on their own, just may take some time, you'll be fine!

For years we've used only the Permatex "Hard-Setting" (1-C) on most studs in the blocks, including the Chevs!

Thanks, Gary in N.Y.

P.S. I would add this "tip", don't put any anti-freeze (if possible) in the build until you've finished the entire break-in period, the anti-freeze makes any small leaks require a much longer time to seal!
 
are thheads flat? was the blocked decked, its a good idea to use sealer on head studs, some go into the water jackets and can lead to weeping, try using a bolck sealer. water glass (sodium silicate) is the best if you follow the directions to the letter, bars leak is another good one, you should not over tighten head studs or head bolts, over torquring causes the metal where the studs are to distort,(pucker up) all around the cylinder where there is a stud, makes it all most imposible for the head gasket to seal, i do not like composition gaskets but in your case i think you should have used one, they compress more than copper, but if water starts leaking around the head the composition gasket will soften and fail prematurely
 
I build alot of blower motors and I always use a product made by Locktite to install studs in a flathead,they live in water. Its is made for course threads and it will take the heat up to 500 degrees. You wont be able to get it at a auto store. You have to go to a industrial supply co. or order it on line from Mc Master Carr. The part number is 577 thread sealent I have never had a stud leak,it even works if someone has run a tap in the block. Put it on the threads and let it set overnight. Anti freeze wont touch it. Yes you can get the stud out. It works great, comes in a tube, you squeeze it out through a nozzle on the threads. Enought to do three flatheads in a tube. Cost around 20.00.
 
Some good information in the previous posts---never over-torque any fastener, never torque one head bolt or stud to a higher level than all the others, use a sealant on the threads at the block. Don't install anti-freeze until the weeps are stopped. Use a "stop-leak" product if necessary. I would only add a word of caution that the thread sealant material can be about anything for studs but must be non-hardening for bolts. Too, all the fasteners should be re-torqued, at least 3 times, after heat and cool cycles.
 
Well it seems the weeping is getting better after retorqueing the nuts after heat and cool down. I have ran the engine up to temp about 5 times now and I am really surprised to see when I retorque the nuts they seem loose and take a slight turn to get them back to around 45 lbs.

Other than that this little flatty purrs like a kitten. Cant wait for a test drive now.
 
Put a large bottle of Barrs heavy duty aluminum stop leak in and that will stop your leaks, lubricate the water pump seal and won't hamper or plug the cooling system. G.M.
 
G.M. said:
Put a large bottle of Barrs heavy duty aluminum stop leak in and that will stop your leaks, lubricate the water pump seal and won't hamper or plug the cooling system. G.M.
Click to expand...

Thanks I think that is good advice. In the early days the car manufacturers actually put stop leak pellets in the new cars.

ALso I worked in a restoration shop that did the same thing to the cars they did with all new engines.

Looks like I might be on my way to enjoying my first flathead.
 
You must log in or register to reply here.
Back
Top