Having Trouble Removing a 12mm Triple Hex Head Bolt OM 617.952 300D
 

Over heated the Engine twice and am Removing the Cylinder Head; likely warped.

I am using a US made K-D 2603 in the attached picture (KDT2306 Features: -Install and remove 12 point (triple square) metric socket head screws with these tools. -Made from heat-treated alloy steel. -Turn with socket or wrench. -12mm Serrated Wrench. Size: -12mm.) Which I bought when I overhauled my Volvo Diesel Engine way back.

When I put the Tool in a 1/2 inch socket it has a overall length of about 4-5/8"

The problem I am having is it worked fine on all but 2 of the bolts. I need to use 2 hands on the end of the breaker bar but the bolts are so tight that the length of the tool+socket cause it to cock. If I had a third arm and hand to keep it straight it would work.

I hate to do it but I am going to cut the tool short so the over all length will about 2 inches. I hate to do that to a US made tool.

I am wondering if someone else has had a similar issue.

I ordered another one on eBay where they are fortunately only around $6 each (K-D Tool 2603) But the replacement is likely to be made in China.

The original Mercedes tool (Mercedes number 617589001000 617 589 00 10 00 144mm long) is even longer and would have the same cocking issue if I used 2 hands on the breaker bar handle.

Can you wait to cut the new one? Would an extension on the triple hex-head get you high enough away that you could hold it with one hand and then use a pipe extension on the breaker bar to pull it with one hand?

Don't cut the tool just yet!!

Spray penetrant on the head bolt.
Use the closed ends of two (6 point) 12 mm combo wrenches on your triple square tool.
Stack one on top of the other.
Tap the triple square tool lightly to seat it in the head bolt (and release tension on the head bolt)
Insert the open ends of the combo wrenches into a pipe or floor jack handle.
One hand on the triple square tool and the other on the pipe, apply a bit more tightening torque, then apply loosening torque.

This hopefully should preserve the triple square tool.
In effect you are shortening the tool without cutting it, when you use the combo wrenches .

It is the other way around the Camshaft with towers and Rocker arms are removed. What is happening is the 4-5/8 inch height is causing it to tilt side ways when I use 2 hands on the breaker bar handle. On the ones that loosened it did not get a chance to tilt much. On the 2 stuck ones it tilts.

If I shorten it it is not going to tilt much.

The tool does not need to be tapped in because it slides easily. It took considerable strength to remove the ones I got out with a 2 foot breaker bar.

Part of the issues is I am bent over the Engine and cannot use any upper body weight. It is all arms and shoulder muscles and nearly 70 year old muscles.

What I think I am going to find is that the head is warped and that is what is making those particular blots so tight.

Concerning cutting the Tool. I ordered one from eBay but you can't entirely count it will get here when it is supposed to.

I have an order from eBay that was supposed to be here on May 13 and it seems like it is stuck in New Orleans.

I have in fact procrastinated on this job and since the bolts are the only thing holding it up I need to get it over with so I can get the parts I need ordered (I need to know if the cylinder head is cracked or there issues with any of the valves).

I used a 10 pc Wintools xzn triple square kit off Amzn. Worked pretty much fine when I pulled my head last year. Removing the rocker arm assemblies and cam stuff helps.

Might consider using a cheater bar on a cheater bar. I put a metal pipe over my 3/8” breaker. Then again, ya could just use an impact gun.... Drop me a line if ya need me to walk ya through it. That nut/bolt on the turbo to block bracket is stupidly difficult to access. Hope your ride is on a lift!

1) Give a thought to fabricating a T-handle 1 1/2 feet on each side. A T-handle eliminates the tilting force.
2) Insert a 3/8" diameter drift into the top of the bolt, and hit it hard with a hammer. That impact acts to release some of the tension in the bolt.

Did you loosen the head bolts in reverse of the tightening sequence?
Failure to do so may cause the last few bolts to bind.

I shortened the tool at the top of the picture and it worked.

I did spray PB Blaster on all of the Bolt heads. However, the problem Bolt even after it broke loose still turned hard all of the way out. As the Bolt got above the head I was able to squire the PB Blaster down past the bolt shaft into the Hole but as you see at the bottom of the picture the PB Blaster never reached the threads. A bunch of scum kept the PB Blaster above the threads.

I have a breaker bar (somewhere) like the one in the picture. The part that is in the center of the picture actually slides. If I found it and used it I could add pipe or tubing on each side.

I got the Bolts out with my shortened tool and a pile on the Breaker Bar to give me more leverage. The shortened tool did not tip.

However installation is going to be different because the head bolts go through the Camshaft Towers and I think I need to get above the towers. Hence the real tool is 144 mm long.

Ya I followed the Manual.

Good you didn't booger the bolt head by just pulling on the breaker bar. Whenever using a long socket (or extension), put one hand on the socket end of the bar and the other on the handle, then push & pull with equal forces. That applies a pure "couple" to the bolt with no tilting force. Similarly, you could use a 2-handle breaker bar (post 8), like the one in my 3/4" drive Harbor Freight socket set.

I've only removed one OM617 head. I bought a special socket tool (1/2" drive, $18 I recall). It has a shaft about as long as yours. I recall it was termed "double square" (8 pt?), but maybe "triple square" is correct which suggests 12 pt. There are normal 12-pt female sockets, but perhaps as a male tool they don't term it "12 pt". I recall seeing that later M-B engines have more common 12-pt "male" bolt heads which take a normal 12-pt socket (female). 12-pt bolts are common in aerospace components, probably because they save a little space and weight and perhaps can handle more torque. It was a bit scary loosening the head bolts, wondering if the high force would strip the bolt head. Might have taken 90 ft-lbf to loosen. If a bolt head got boogered, you might drill off the bolt head, remove the engine head, then remove the bolt stub with vise-grips.

I did not have enough strength bent over to use only one hand to pull and one to hold and I was buy my self. What I did modifying the tool worked fine.

The descriptions of the tool were copied from the sellers.

I measured the some of the lengths of the bolts as per the Manual and 4 cannot be reused some can be reused.

Some people have drilled off of ground off the bolt head but if that does not loosen it or you cannot get the bolt to turn when you remove the head you have to lift the head straight up above the length of the bolt.

Kroil Penetrating Oil has never failed.....
 

use a syringe with a needle to carefully apply Kroil penetrating oil to the bolt. The Kroil will seep down to the threads. Just before you go to bed, put some more Kroil Oil on the bolt using the syringe with a needle. Next day, use MAP gas heat to heat up the bolt. This method has not failed yet......

Once you try Kroil Penetrating Oil you will wonder how you ever got along without it.....


https://www.amazon.com/Kano-Kroil-8oz-Can/dp/B00DR7F4AO/ref=sr_1_25?crid=748DHVODRGOF&dchild=1&keywords=kroil+penetrating+oil&qid=1621799334&sprefix=kroil%2 Caps%2C321&sr=8-25