Leaking head gasket
 

So here’s my problem. I’m working on getting my 28 CCPU running. I’ve rebuilt the carbuerator and fixed a few other small items. Tonight I’m happy to say that I got it running for the first time in about five years. Super exciting. Unfortunately, I now discovered a leaking head gasket above the exhaust manifold. I am being told the the gasket was changed about six years ago when work was done on the engine to get the engine unseized and running. I doubt the engine was ran at all until now. In reading the forum, some suggestions say to re-torque the head bolts, as I’m sure that hasn’t been done. Do I do that, or should I replace the whole head gasket? And since I’m new to working on this truck, how hard is it to just change a head gasket? Thanks.

Re: Leaking head gasket
 

I would give the head a retorque 55ft lbs. Changing the head gasket wouldn't be a bad job as long as it isn't stuck to bad.

Re: Leaking head gasket
 

Give it a retorque first 55lbs. If that fails then replacing one isn't all that hard but when you take the head off try and check that the head is smooth and flat, it may need to be sent off and surfaced. But don't assume the worst until you've ruled out the simple.

Re: Leaking head gasket
 

Get a diagram for proper torqueing sequence. This is important! It may be that that was not followed when the head was last off. Also, I would back off the nuts about a half turn before retorqueing. Just a little bit, not more than a half turn back, then torque. Some oldtimers suggest backing them all off a couple turns before retorqueing. Then retorque in proper sequence. If you do it that way, drain your cooling system so no water leaks into the crankcase.

Torque to 55 lbs.

After that procedure, and after you've refilled the water and run it sufficiently to get it fully warmed up, retorque again, in sequence. After about another half hour of good running, I retorque again. You should too.

If it still leaks after all that, but not too badly, put some good quality sealant in the cooling system. If it still leaks (I'd be surprised, unless there's a crack or warpage), then pull the head.

Re: Leaking head gasket
 

An additional note on pulling the head: This can be difficult, especially as in your case if it's been on there a while. You have to pull the distributor, disconnect your ignition cable from the dissy, and remove your upper radiator hose, and then hope the darn thing isn't superglued on. If it is, get one of those good head pullers (about $80 from most suppliers, or borrow one if you can). You may also have to remove either or both your water pump and fan, depending on what type of fan you have. Your radiator support rods can also make the work troublesome. This is not a complicated job, but I find it annoying and try to avoid it if I can.

Re: Leaking head gasket
 

Great idea on sequence.

Re: Leaking head gasket
 

Be sure to check the oil as the coolant can go down the distributer shaft. I would torque and use some stop leak before pulling the head.

Re: Leaking head gasket
 

I'm not a fan of backing the nuts off before re torque, but if you do choose to do it that way, go half way, say 30lbs, in Sequence, and then on to 55, in the correct order. Like was stated, you may have drive it and do this a few times before it ever takes a set. Good luck!

Re: Leaking head gasket
 

Something doesn't sound right.If a new head gasket was put on years ago,and not run,or not run much,to have it start leaking after just a short time isn't right.It shouldn't be leaking and need a retorque so soon,unless something else is wrong.They could have used a used gasket,damaged it,something might be in there,it may have a crack.Also,to have a leak on that side is not that common so I would be looking around first to find a problem.The water pump can leak and the water run down,hit the seam at the head gasket,and then follow the gasket back and drip off at the rear.

Re: Leaking head gasket
 

Rex,
I think we are in agreement but if I may add a little more clarification: JMO: When backing off the nut before re-torqueing, one should only back off a minor amount. I only back off until I feel the nut move and then a tad more; way less than 1/8 turn. I would say the typical amount to back off is only about 5-10 degrees.
The objective of backing the nut off is to eliminate the "stiction" (static friction) between the two surfaces. We do not want to significantly reduce the torque the stud and nut are applying to the assembly.

"stiction" I hate that portmanteau. I don't like the word portmanteau much either.

Good Day!

Re: Leaking head gasket
 

Don't go crazy on the two water neck nuts. The water neck casting ears can crack easily.

Re: Leaking head gasket
 

Maybe they didn't torque the head when they did the head gasket years ago?

Re: Leaking head gasket
 

Rebuild a 504 diesel tractor torqued everything to spec's and I tea rebuild a 504 diesel tractor torqued everything to spec's in IT manual and the water was running out of the head had me stumped because this was not my first rodeo! I took tat motor apart and put it back together while I was sleeping that night. I wish I could tell you that I had figured out the problem when I woke up but no! I was prepared to spend the day taking it apart when it dawned on me to google the torque specs. Google showed 35 ft.lbs tighter problem solved. Recheck IT manual they had gas and diesel the same. Do not panic put some Aluma seal in it bring it up to temperature let it cool and re-torque :rolleyes::eek::eek:

Re: Leaking head gasket
 

Rebuild a 504 diesel tractor torqued everything to spec's and I tea rebuild a 504 diesel tractor torqued everything to spec's in IT manual and the water was running out of the head had me stumped because this was not my first rodeo! I took tat motor apart and put it back together while I was sleeping that night. I wish I could tell you that I had figured out the problem when I woke up but no! I was prepared to spend the day taking it apart when it dawned on me to google the torque specs. Google showed 35 ft.lbs tighter problem solved. Recheck IT manual they had gas and diesel the same. Do not panic put some Aluma seal in it bring it up to temperature let it cool and re-torque :rolleyes::eek::eek:

Re: Leaking head gasket
 

I am sorry, Siri and I have a love hate relationship, I think she hates me
,

Re: Leaking head gasket
 

I replaced a head gasket and found it weeped on the manifold side I retorqued it after a short while but no change . A dose of "Barrs Stop Leak" cured it, no leak now after several years .I dont know if you have Barrs in USA but anything similar should work .

John in misty morning Suffolk County England .

Re: Leaking head gasket
 

Do you know where the rest of the 'Alumnaseal' and 'Barrs Stop Leak' goes after the little bit gums up your leak?...it gums up your radiator tubes..

Your wallet better be ready if the head comes off,an 'engine unstuck 5 years ago' can be ugly.

Re: Leaking head gasket
 

I don't think Alumaseal would hurt the radiator as it won't settle out. Bars leak works well also if it is a fresh can. These products have been in use since your car was a baby, and I haven't read about any lawsuits for damaged radiators. Use as directed.

Re: Leaking head gasket
 

I agree with the re-torque and pay attention to the fastener by the distributor. Someone may have wimped out on it. I always pull the distributor to tighten.
Barsleak, the modern stuff has particulate in it that will plug the radiator and wipe out the water pump seal and shaft.
good luck

Re: Leaking head gasket
 

I've used Barsleaks many times without issue. A little while ago, I took a close look at the pellets in it. THEY ARE CHICKEN $#!T. We have a product here call Dymanic Lifter. It is garden fertiliser made from dried, pelletised chicken manure. I'm sure that is what is in the oil we pour into the cooling system. On reflection, it should work well as it would swell as it absorbed water and seal a leak. I can't see soggy chicken crap causing wear on the shaft or plugging the radiator.