How to remove a frozen bolt from a Aluminum intake manifold.

[MacGyver]

I attempted to remove a bolt from a Aluminum intake manifold and it appears to be frozen. It's not my vehicle so I really don't want to break the bolt off or strip the threads. I am trying to figure out the best
way to break it loose. Because the intake manifold is aluminum I do not believe heating the area around the bolt will work.

What would you do?

[27 sportfisher]

is the bolt through the manifold or threaded into it? plan a: a little heat wont hurt. i have had best luck with pb blaster. the more you hurry the more likely it will break. plan b: drill.

[.338WM]

Is this a bolt that goes through the manifold and holds it to the head, or does the bolt hold something onto the manifold ?

If the bolt holds the manifold to the head and it breaks removal will not be terrible, it may be very simple actualy. Most times the source of binding is dis-similar metal corrosion between the bolt and the manifold, not on the actual threaded area, this means that should it break it will break well above the surface of the cyl. head leaving a good "stud" to get ahold of allowing for easy removal of the remainder-the corrosion normaly does not get into the threaded area unless it is adjacent to a water jacket-motor oil is normaly present otherwise.

IF the bolt is holding something onto the manifold chances are much higher that it will pull the threads and a heli-coil repair will be in order.

To aid in removing the bolt in either case; obtain a brass drift/punch and place it atop the bolt head, rap on the drift with a hammer a few times to loosen the corrosion/thread then, attempt removal again. If it is still reluctant spray a quality penetrating oil around the bolt Aero-Kroil is excellent for this. Tap a few more times after it has had some time to soak in. This method can be employed to the remainder of the broken bolt, if that happens.

Odds of successful removal if the bolt is through the manifold to the head NOT adjacent to a water jacket is good.

Odds of success if adjacent to a water jacket are a coin toss depending on whether the corrosion is into the manifold boss and threads or just the boss.

Odds of pulliung threads if the bolt is holding something onto the manifold, likely, but repair is normaly very easy.

BTW, what is the make, model, year of this engine ? I can shed a little more light on this if I know.

[retiredinhomer]

I attempted to remove a bolt from a Aluminum intake manifold and it appears to be frozen. It's not my vehicle so I really don't want to break the bolt off or strip the threads. I am trying to figure out the best
way to break it loose. Because the intake manifold is aluminum I do not believe heating the area around the bolt will work.

What would you do?

If the bolt is bolted only to the aluminum; Heat will work to help remove it. If through then the pb blaster will help.

[JOAT]

Ditto the dousing with Kroil and then let it sit for a minimum of a couple hours, but overnight is better.

Follow that with some heat. Aluminum responds very well to heat. Different expansion rates between aluminum and steel means a good chance of breaking the bond between the 2 metals as they are heated up. If you can heat primarily the aluminum and less on the bolt, the effect will be that much greater and you ought to be able to spin the bolt out with your fingers.

[MacGyver]

It's one of two bolts that hold down the thermostat housing. I'm guesting it goes through the manifold in to the water jacket (most do). I also don't think a spray will penetrate into the aluminum. Yes I know all about drilling and using a easy out or drill and tap I just don't want to.
It a Chevy 350 and not mine.

[retiredinhomer]

I know those bolts I heated up the manifold and still broke one. Drain the fluid out then try the heat on manifold. A hand impact wrench might break it free. If you don't have one tap the top of the bolt with a hammer while turning. Lot of corrosion one bolt is blind and the other goes into the water jacket that is the one I broke.

[.338WM]

It's one of two bolts that hold down the thermostat housing. I'm guesting it goes through the manifold in to the water jacket (most do). I also don't think a spray will penetrate into the aluminum. Yes I know all about drilling and using a easy out or drill and tap I just don't want to.
It a Chevy 350 and not mine.

You are correct, the bolt holes do penetrate the water jacket on that engine. If the Kroil and tapping do not loosen the bolt enough to turn it out you will likely pull threads from the manifold before snapping off the bolt head but, not a guarantee. Anyhow, if the bolt head snaps off tapping the housing side to side will get the housing off. Penetrating oil will work its way down the threads and help to weaken the corrosion, especialy aided by tapping and soaking for some time, multiple applications may be needed, patience is also important.

If the bolt head snaps off rather than the thread being stripped from the manifold then the major point of resistance is/was between the bolt shank and the boss of the housing, this can actualy be a good thing. As I said before it will leave a 'stud" to grip and odds are good that it will come right out. If that is the case, be sure to use a pick and scrape away as much as possible all of the corrosion around the bolt then, re-apply the Kroil and let soak again before attempting removal if still stubborn.

If the threads strip, repair with a heli-coil is a cake walk since there is a pilot hole for the required drill bit and tapping aluminum is very easy. Whatever course of action you decide remember this : use an anti-sieze on the new/clean threads either nickel or copper based or teflon paste to prevent the same problem in the future. This is a notorious problem on these engine, especialy if it uses the worst automotive fluid ever introduced.....DEX_COOL.

[Contender]

Several years ago I had this happen to me with a Ford 351 on my jetboat. I did all of the above and ended up with a die grinder on my air compressor and cut the head off of two bolts but it was pretty tight to keep from cutting into the aluminum manifold. I had allen head bolts on mine and they rounded out the inside of the bolt head. I used two big pry bars to bring the manifold back over the two broken bolts and then a large visegrip threaded them both out of the head. Good Luck

[Magnum Man]

Im pipefitter plumber by trade and quazi jet boat mech. Take a propane torch (this can be overdone of course)to it all and hit with pb blast or your favorite penetrant while hot. Let cool and repeat a couple times. Then get it good and warm again and try to break it loose( While hot) when the metal is hot it will draw the pb into the threads better as the metal is expanded making more room between the threads. Allowing the fluid to get in deeper. The penentrant will chase the heat like like solder on copper. I use this to get old pipe nipples out of boilers and for getting exhuast bolts loose on v8s. good luck

[akmike30]

Simple get bolt really hot melt wax all over bolt let cool off take bolt out...

[akmike30]

If you mess the treads up not a big deal. The make helli coils for every thing.

[anonymous1]

We tried this mixture in our machine shop. You gotta shake it up good to keep it mixed and its very flamable but in some cases the results were amazing compared to the others.
Try heating the hex top of the bolt with a small tipped flame until quite hot. Let it cool a little and put on some penetrant and wait an hour or so.

Best Penetrating Oil Test, surprise winner

--------------------------------------------------------------------------------

Haven't seen this here so thought I would post this article regarding various penetrating oils and how well they work. Several surpises.

I have the fixings in my garage now so essentially the best is free for me.

Jim Henderson

Thanks to Matthew J. Michalik who posted this on the Yahoo group:


Machinist's Workshop Mag (tm)recently published some information on various penetrating oils that I found very interesting. Some of you might appreciate this. the magazine reports they tested penetrants for break out torque on rusted nuts.
They are below, as forwarded by an ex-student and professional machinist.

They arranged a subjective test of all the popular penetrants
with the control being the torque required to remove the nut from
a "scientifically rusted" environment.

*Penetrating oil .......... Average load*
None ........................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ............... 127 pounds
Kano Kroil .................... 106 pounds
ATF-Acetone mix...............53 pounds

The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone. Note the "home brew" was better
than any commercial product in this one particular test.

[kodiakcombo]

[The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone. Note the "home brew" was better
than any commercial product in this one particular test.[/QUOTE]

Wow, that I got try.

[anonymous1]

NOT for prop nuts. Jeff


justkiddin

[kodiakcombo]

ok, very funny. We are going to pull the D4 out of the seasport and reset it(change out hoses and hard to reach parts while its out), so Im sure we will have stuck bolts and such.

[alaskabliss]

Great information on the different penetrating lubes. Thanks. We use Kroil a lot on the slope and it works wonders but the homebrew idea is a must try!

[akmike30]

Yep sum good ideas. But after Working at exhaust shop when I was in my 20,s nothing works like wax.

[gunner]

Gotta agree with you akmike on the wax. An old marine port engineer taught me this years ago. Heat the hell out of it, then run a cake of parrafin on it. Would guess a presoak with kroil or homebrew wouldn't hurt.

[akjeff]

+1 for ATF and Acetone. It's called "Secret Sauce" where I work (aircraft maintenance). Kroil is good too, but not everyone has Kroil.

*Penetrating oil .......... Average load*
None ........................... 516 pounds
WD-40 ..................... ... 238 pounds
PB Blaster .................... 214 pounds
Liquid Wrench ............... 127 pounds
Kano Kroil .................... 106 pounds
ATF-Acetone mix...............53 pounds

The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
transmission fluid and acetone. Note the "home brew" was better
than any commercial product in this one particular test.