I am getting quite frustrated because I have not been able to loosen the small bolts to replace the thermostat, the throttle position sensor and the EGR valve. I do not want to twist the bolts off as that will cause me to have to attempt to drill them out. Some are in difficult places to drill.
Do any of you have a favorite way to get these bolts to come loose from cast aluminum. I have considered using penetrating oil. As a last resort heat may be used, I suppose but would rather not.
Thanks for any help.
RagJag

 

PB Blaster is my favorite to use.

Does't always work, but I suppose it depends how many applications over how long a period you allow it to penetrate...

I've broken a bolt at the EGR Valve before. Sucks.

 

Use the oil and tap bolt to brake free and allow oil to penetrate. Repeat as needed. Let oil sit overnight.

 

I recall reading a post by OB, wherein Greg suggested using a 50/50 mixture of acetone and ATF, using a paintbrush to apply it and doing that daily over the course of a few days. I haven't tried it yet, but that will be my first choice if I ever need something like that.

 

I start with what BC XJ said, then:
First try to tighten just a tad, so that you round off these edges, still leaving you with some hope.

If that does not work then try banging on the bolt head with a punch to try and break the lock

Then bring out the MAP gas torch. shield surrounding parts of course

Then impact wrench

All of the above is dependent on reach and accessibility of course.

If its buggerred up by then, then I reach for the extractors.

Sometimes due to accessibility considerations I've had to cut slots in the bolt and use a screwdriver sideways to get more leverage.

Good luck

 

One tool that has not been mentioned is a hand impact tool. It is about 8 inches long with a bit on one end, the anvil mechanism is in the handle. The end of the handle is struck with a BFH. The impact keeps the bit anchored in the fastener head and the impact breaks the corrosion free. Still don't have one, but last time I looked they were under $30.

It is used for tight screws which are at risk of rounding. Commonly used for gearcases on motorcycles. Also used on alternator case screws.

Strange thing is that I have never hesitated with tight fasteners until I started reading JF

 

Hi Rag Jag

I've had some really amazing results with using 50/50 Acetone/ATF@ 'Greg in France'

On Stuff that I thought would never come undone!

You've just got to rig up something that keeps the mixture continually soaking the bolt in the stuff.

Like surrounding the bolt in cotton wool soaked in the mixture or something like that and then be prepared to wait for as long as it takes.

 

"considered" penetrating oil?? What is the point in considering it? Just spray penetrating oil all over it, let it sit for 15-20 minutes and take the damn things off!!

Only other tip I can give is use a breaker bar is adapters if you don't have a long tool set.
Other tip would be to double up on wrenches for leverage or use an extention on ratchet to get it out far enough to use a wrench on its end for extra leverage.

tighten it back up like a normal person and not the ******* that replaced them last. They don't need to be very tight. idk if there are specs but I wouldn't guess more than 20 ft/lbs, its probably closer to 12-15

 

Leverage is not the problem with 1/4" bolts. Breaking them off is the problem.
RagJag

 

If you strip the bolt heads or nuts try an outside easyout before drilling them.
With an outside easyout you can remove a rounded bolt or nut like nothing at all

 

Tap the top of the bolt with a small ball peen hammer. If you're doing right the hammer will seem to bounce off the bolt and listen for a ringing sound. Adjust the force of the blows until you get a resonant sound. That should cause micro cracks in the corrosion. Use the smallest ball been you can find and be sure you're transferring energy to the bolt itself by striking it in the center using the round side of the ball peen. Then try to tighten it ever so slightly before trying to back it out. A pretreat with some sort of penetrant couldn't hurt. Good luck!

 

icsamerica, I tried your method on the EGR bolts and it worked. I believe the hammer did the trick plus an overnight soak with Master Blaster. The bolts aren't accessible to hit with the hammer so I used a punch to reach them.
RagJag