My newly rebuilt 292 is leaking coolant (little rusty chalky looking trails) down the sides of the block along the bottom edge of the heads on both sides. Rusty water spots on the oil pan where drops blow off. It only seem to happen when the truck is run at highway speed. I can't see it leaking when I am lying under it with the motor running. I have checked the torque on the head bolts that can be reached without pulling the headers and they are all at least 75 ft/lbs. Should I try to tighten these to a higher torque (if so how high is too high?) or should I figure on a new set of head gaskets. BTW the heads were planed and the block was decked to make it level during the rebuild and all of the bolt holes were cleaned to help assure a tight and accurate fit. Any suggestions before I have to tear this thing down again?

 

dont put any more torque on the head bolts.i wouldnt do anything until i was sure where the leak is.

 

What type of head gaskets did you use- steel shim, or composition? Did you use any kind of sealer on them?

Did you use the right bolts in the right holes? (Two of the lengths are pretty close in size, but not exact.)

Run it up to temp with the radiator cap off, & look for bubbles in the coolant. Also, is there smoke in the exhaust of any color? White, gray, etc.

I agree with 312, don't tighten them any further than the torque spec. But, a couple of more things: I'm assuming that you used specs, right?? (We all know what happens when you assume ) The holes were cleaned- bolts too, right? Did you use any oil, sealer, or any other goop on them? Did you retorque after the first fire-up/cooldown?

Not trying to insult your skills, just running through possibilities. Gasket leaks make you want to (as my son says) either cross your fingers..., or hold one particular one of them up.

 

Leaks are along bottom edge of heads (both sides) below exhaust headers where head meets block. Can't actually see leak in progress...only trails down sides of block after driving the truck for a while.

Composition gaskets no sealer.

No detectable smoke from tail pipes.

Bolts appeared to be all the same longer ones on top shorter ones on bottom below headers. I am not the first to rebuild this engine and they could have been replaced by previous mechanic. All clean and installed dry ...torqued to 75 ft/lbs.

Vaccum steady at around 20 in/mg.

Compression equal on all cylinders at around 110 to 115 psi.

Good idea about the bubles in the coolant ...I'll have to check that.

Didn't retorque after first warm up and cool down but did check bolts that could be reached and they were still torqued to 75 ft/lbs. HMMM * just had a thought....My torque wrench isn't the top of the line model and has seen some years of service....I think I'll check to see if it is accurate!

BTW you can't insult my skills....I got a GED from the School of "Do it over till it's right" and A Master of Mechanics from "Shade Tree U" I learned most of my mech skills from watching and listening to the kind of people that post on FTE.

Yep... It makes me want to give it the I'm #1 sign with a certain middle finger but these old trucks are like family...You just can't help but love um and try to make um better.

Thanks for the suggestions and Ill let you know how it comes out.

 

Burt, from the description of what has been done, with composition gaskets, leaking head gaskets are a big surprise.
On the top row of head bolts, the holes on each end of the head, the holes corresponding to the dowel pin locations, take bolts that are slightly longer than those in the interior. It is a common mistake to mix them up. The motor I tore down 2 years ago had two of the longer bolts in interior holes.
The longer bolts are 4.32 inches long.

 

ive ofter seen the head bolts mixed up.is long as they hold it makes no difference.check all your hoses at the front.the one that goes from intake to water pump etc,.if they leak they can run back along the engine when your driving.theres no way those gaskets should leak with what you done unless a major mistake was made.

 

Get a cooling system pressure checker. Put it on the radiator and pump up the pressure. Now does it hold. If not start looking for a leak somewhere. Do this cold and after the engine is hot. Be careful when doing it hot. You may also need to do this with the engine running.

 

Note to self...get new torque wrench . Checked mine against a buddies aaaand ..... it's broke. Closest I can tell is I had the heads torqued to about 60 ft lbs..... Funny how cheap a good tool is when you consider it could save you a days worth of hard labor.

Things I have discovered during this little lesson.

1. There is a lot of good information from the experts here at FTE. Thanks Everybody!

2. Good tools pay for themselve's !

3. The long head bolts in 1955 Y-blocks (like mine) are all 4.06 inches. According to Eickman Book, Ford started using the two long ones in each head in 1956. Whew.... that one had me scratchin my head when I pulled them out and they were all the same length.

4. If you try to torque an old galley pan to 2.5 ft/lb (per Eickman Book) you will warp the #X!~!## out of it.

5. Workin on this old truck would be a whole lot more satisfying if something would work right the first time I do it.

Still have to put in the rocker assemblies, intake and exhaust manifolds and refill the radiator before I'll be able to crank it up and see if it's fixed. Probably another 1/2 days labor.

I'm keeping my fingers crossed.

 

Someone please correct me if I am wrong, but I beleive the head bolts should be lubricated with oil or sealant. If they are installed dry the friction will cause the torque wrench to click before the correct torque has been reached.

 

Buns, I know from previous experience not to use sealant on the head bolts. What a mess when you do another install, and unnecessary! It took a long time to clean the threads of all that gunk. As for lubing the threads, I've read discussions on it, and do not myself.
Burt, guess it is good that it was most likely your torque wrench and not a bigger problem. Sorry about the info on the bolt lengths. Thought you had a later model.

 

If their is water or something is under the bolt when it is torqued it will give a false reading.