How to Not Break Head Bolts?

[Akstraw]

I recently bought a Model T that has been sitting in indoor storage for about 32 years.  Was a good running car before that (Yes, ‘Ran when parked.’)   I’d like to pull the head and pan to check the engine out.  What are your tricks to avoid breaking stuck head bolts in the process? 

[Matt Harwood]

Lots of penetrating oil, lots of heat, lots of time, lots of patience.

And plan on drilling out at least 3 of them.

[keiser31]

I always try to tighten them a little bit before trying to remove them. Most of the time it loosens them just enough.

[pmhowe]

In the past, I have had good success using Keiser31's approach. but I am wondering, would it be even better to start with his approach, and then use an impact wrench? It seems to me that one is more likely to do more damage (i.e. are more likely to break a stud or bolt) applying brute force with a breaker bar than to have the pulsating force application of an impact wrench. What are your experiences?

[Bloo]

I'd ask on the MTFCA forums, since it's a T.

 

In general though, rust is strong, but very brittle. Shock waves break it. Things like hammer hits, ultrasonic energy, heat expansion, etc. are your friend. Don't just use a giant cheater bar as a first option. Try to mess up the rust instead. A piece of steel like a bolt is effectively a spring you can twist. You can only twist it so far before it yields. A soft old bolt from the 20s might yield fairly easily, and even more so if there is rust damage concentrating the force at a thin spot. The yield point is a place you do NOT want to be.

 

Instead, put some load on it like some constant pressure with a box end wrench. Maybe a cheater bar too but don't kill it. Keep holding the load against the bolt and hit it's head with something like a brass hammer. Not a deadblow or plastic or leather hammer or anything soft. You want to SHOCK it. Sudden shock waves, without putting enough rotational torque to actually twist it off. Imagine you are trying to break glass. It is about the same.

 

37 minutes ago, pmhowe said:

In the past, I have had good success using Keiser31's approach. but I am wondering, would it be even better to start with his approach, and then use an impact wrench? It seems to me that one is more likely to do more damage (i.e. are more likely to break a stud or bolt) applying brute force with a breaker bar than to have the pulsating force application of an impact wrench. What are your experiences?

Absolutely correct. I hesitate to suggest it because how to "finesse" a rattle gun is not obvious, and something most people have never done. It is hard to describe in print. I'd use a big rattle gun turned way down. I wouldn't squeeze very hard either. Lots of shock, but hopefully not enough twist to go beyond the yield point. Too much and you twist things off even worse than with a cheater bar.

 

Edited December 8, 2023 by Bloo (see edit history)

[Angelfish]

I've had good luck with impact tools, either pneumatic or the common cordless type.  As said above, turn the power down and go easy.  I've snapped more bolts with a breaker bar than I have with an impact gun. 

 

And a product plug, PB Blaster is as good as they claim it is.

[EmTee]

I've seen others use an air chisel with a pointed tip on the end of the stud or center of the head to 'rattle' the threads, as Bloo suggested.  Once the nut starts to move, keep alternating between 1/4 turn CW and 1/2 turn CCW until the threads are cleared and resistance is low.

[Jolly_John]

And, Gang, if you're dealing with a nut on the end of a stud, use the old wax candle trick from 100-years-ago. Heat up the nut and stud (extreme heat is NOT needed), and then touch a wax candle (even a little birthday candle) to the joint of the nut and stud. The wax will get sucked in.  Then, just easily loosen the rusted, problem nut with your wrench. Amazing results, and works every time.

 

I astounded my 17-year-old grandson with this technique this past weekend, while we were working on his rusty old Subaru Outback. Hopefully, he's learning that "work" doesn't always have to involve a smart phone or a computer. John

Edited December 9, 2023 by Jolly_John (see edit history)

[Oldtech]

In my experience T's usually come apart pretty easy, unlike, say , a Studebaker.  I like the impact. Not cranked to where it will just twist it off and fling it, but enough to rattle it good.  Best of luck.

[Akstraw]

Thanks, Gents!  These are the types of tips I was looking for.  Wish me luck!

[MikeC5]

It mightbe a good application for an induction heater.  https://www.amazon.com/Magnetic-Induction-Automotive-Flameless-Removing/dp/B09CPX851W/ref=asc_df_B09CPX851W&mcid=a5a83b444afc3db48c33dd12173c2fc4?tag=bngsmtphsnus-20&linkCode=df0&hvadid=80470624769029&hvnetw=s&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584070155793711&th=1

[Lahti35]

On 12/8/2023 at 9:06 AM, EmTee said:

I've seen others use an air chisel with a pointed tip on the end of the stud or center of the head to 'rattle' the threads, as Bloo suggested.  Once the nut starts to move, keep alternating between 1/4 turn CW and 1/2 turn CCW until the threads are cleared and resistance is low.

I've used a nearly identical process with an air impact gun on exhaust studs/nuts... I just turn the air down low until the gun just shocks the fastener and they seem to break loose fairly easily. The goal is to just shock at first, not back it out.... Think slow firing machine gun... Once they start to loosen I run the impact forward and reverse until I get it moving 360 degrees good and then back them out slowly. 

[mikewest]

Ive never broke a head bolt on a T ... But if worried about it plenty of Lousy Goosy and a impact gun set at low pressure and like the others said, give it a little to the right and a little  to the left. Usually if a stud breaks its in the head or the flange its holding  . The other trick that works great is get on the stud with heat red hot and quench it with lots of water, It shrinks the bolt. Ive used that on door hinges where you can get behind and heat the threaded area on the post. It works wonderful.

[EmTee]

If I'm pretty certain that a bolt or nut on a stud can't be removed without substantial risk of breakage, i have preemptively drilled-out and removed the bolt head or nut, leaving the shank/stud.  That way, once the part is removed you'll have access to the threads in the block for penetrating oil and still have the full length of the shank (or stud) to grab with a small pipe wrench or vicegrips.

[Stude Light]

Be glad you don't have 26 studs and an aluminum head. A little corrosion on the studs and you are in for it. I had to use every screwdriver and pry tool I had.

Once I got the head off I had to pull all the studs that have been in place since 1923. First penetrating oil, then heat.

Then let cool and double nut as hard as you can and get the flats aligned for a 6 or 12 point socket.

Then get the Vice Grips out and lock them on as hard as you can.

Now hit it with the impact gun while simultaneously smacking the Vice Grips with a sledge hammer.

And after several hours they all came out. Didn't break any nor pull any threads and they all terminate into the water jacket!

 

Now with head bolts you don't get to heat down close to the block but you at least get to break the bolt-to-head bond individually. I had to beat the hell out of the aluminum head from the piston side while tapping in all the wedges to finally break it free.

 

BTW - if you snap off a head bolt flush to the block, just drop a nut over it and MIG weld inside of the nut to the top of the sheared bolt. Hit it with an impact while still a bit warm and it'll come right out.

 

[dodge28]

keiser31 method is standard practice of the trade. If you want to try something a little different to supplement keiser31 idea use a # 4 gas welding tip and heat the head just around the bolt head and hammer the bolt head a few whacks. Always use steady pulls on your spanner, not jerky ones. ( Heat the head, not the bolt)

[Frank DuVal]

On 12/7/2023 at 10:47 PM, Bloo said:

Not a deadblow or plastic or leather hammer or anything soft.

Are you thinking all dead blow hammers have soft faces? ❓

 

I have several ball peen dead blow hammers with steel faces. I do not have one with a brass face I might have to get one, they are cheap now, here is one for $13:

 

https://www.amazon.com/Klutch-Brass-Dead-Blow-Hammer/dp/B07STGCNXR

 

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