Worrysome head leak...help!!

[MurphyJ]

Ok, I have installed one of Mac's modern silicone coated head gaskets and while going through my first re-torque sequence I found a dribble of coolant coming below the base of head bolt nut number 2 on the torque sequence pattern. I went ahead and re-torqued all nuts to 55 lbs. and this morning when I checked there was again a dropplet of coolant at the base of number 2 nut. What to do???? Go through another heat cycle or two and re-torque hoping that the new head gasket needs more seating pressure?
Figure that IIgot a bad head gasket and go through the head removal process and install another new head gasket? Yes, I did have the head decked, cleaned and magna fluxed before installing and the block surface was well cleaned as well. I am open to any and all help, suggestions, clues and prayers!
Thank you.

[dwollam]

Probably leaking past the threads of the bolt. I had one do that in the center of the head. I pulled the stud and put some sealer on the bottom threads of the stud, put it back in, problem solved.

[CarlG]

I found on mine that several of the stud holes had been drilled thru to the water jacket when they put in Helicoils sometime in the past. Sealing the threads with something is the only way to remedy that, and sometimes it takes more than once to stop the leaks completely.

[MurphyJ]

Thanks for your quick response to my problem. Questions: What is the sealer i should use to seal the bottom on the leaky stud? Also, can i pull the problemsome stud, apply the sealer without draining the cooling system or is it necessary to drain all the coolant possible? I thank you again.

[Del in NE Ohio]

Remove the troublesome stud and put a small amount of red permatex gasket sealer on the bottom 3 or 4 threads and re-install...should stop the "weeping"

[Del in NE Ohio]

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no need to drain coolant.

[1crosscut]

I'd drain the coolant.

[Tom Wesenberg]

Originally Posted by Del in NE Ohio

no need to drain coolant.

If that stud hole is drilled into the coolant, then removing it to add a sealer should require the coolant to be lower than the hole.

[James Rogers]

I would remove the nut and wrap the stud at the level of the head with dental floss. 10 or 12 wraps should do it. Replace the nut and torque. Easy to do and might save some trouble.

[zzlegend]

Great idea James. Never would have thought of that. Gotta love this Ford Barn. Mark.

[Larry Seemann]

First, let me say that James is correct - not that he needs me to affirm that he knows what he's talking about. But, I think it warrants a little explanation as to what is actually happening. First, you should understand that the situation you have is not at all unusual. Second, it's not serious. Third, it's not a "leaking head".
Here is what's happening: The water jacket holes in the head are lined up with holes in the head gasket and in the block and coolant moves through these holes from the block through the head gasket and into the head. As it moves the coolant comes into contact with the filler material in the gasket and can "wick" through that material to where a stud goes through the head gasket. When it gets to the stud the coolant can "climb" the stud until it makes it's escape onto the top of the head.
Wrapping with thread, as James suggests, blocks it's escape path and you don't see it.
Many a Model A owner has had this same situation and most of the time it will correct itself with corrosion and just simply quit "leaking".

[Greg out west]

Hey Murphy,,


Mine did the same thing..put in some aluma seal & keep retorquing the head..It will stop..BTW torque the water outlet nut's "Together" & don't use a thick paper gasket !!!!!!!!!


Greg out West

[BILL WILLIAMSON]

This is exactly why I seal the lower stud threads with BLUE loctite & tighten them snug! NO need for anyone to YELL at me, I've got the sound turned down! Bill W.

[pat in Santa Cruz]

Permatex makes thread sealants for this purpose, although dental floss is probably cheaper. I have used the white product and like it

http://www.permatex.com/products/pro...sealant-detail

other products for similar jobs:

http://www.permatex.com/products/pro...hread-sealants

[Rock Hornbuckle]

Plumbers teflon tape was designed for sealing pipe threads, should work fine on head studs. I have used it to seal the threads on pipes carrying high pressure steam.

[Logan]

Do like others have said and try to seal the stud. But if you have to end up replacing the gasket, get a BestGasket head gasket. Those head gaskets with the silicone bead already placed in them aren't worth a crap. The BestGasket head gasket is your best bet for a good seal. Just spray it with some copper coat and put it on and you'll be pleased with the results.

[CarlG]

When I bought my ARP studs, I also bought thread sealant from them. It has their name on the tube, but it's sort of a white paste. Time will tell if it works as advertised. I do have a couple of holes through to the water jacket where they were drilled too deep to install helicoils BC. (Before Carl)

[Jim Johnston]

CarlG,

Where did you get your ARP Studs? I checked their on-line catalog and didn't see an application or part mumber for Model 'A'.

[George Miller]

I think it would be best to take the stud out and seal the treads where it goes into the block. If you seal it at the nut and leave water in there, you may have a hard time getting the sud out down the road from rust.

[CarlG]

Originally Posted by Jim Johnston

CarlG,
Where did you get your ARP Studs? I checked their on-line catalog and didn't see an application or part mumber for Model 'A'.

You won't see anything in their catalog, and the young'uns on the phone don't even know what a Model A is.

However, here's what you need:
11 ea AP3.500-ISB
1 ea AP3.75-ISB
2 ea AP5.750-ISB

If you are not using the cable clamp on #8, just get 12 of the first item.