Stripped / Rounded Sump Bolt

[Lukas]

This is for someone at work, and not on an MB:

The sump bolt head has been rounded by a failed attempt to remove it with a ring spanner. A subsequent attempt with a pair of multigrips also failed.

Does anyone have any ideas for how to get it off?

It's a conventional protruding bold head. Obviously the bolt will need to be replaced once removed, but the objective is to not damage the sump.

Ta

Lukas

 

[WGB]

I would try a small pipe wrench as the jaws tighten the more you put pressure on it and bite into the metal.

Obviously you will need a new sump plug and seal - whatever happens.

Bill

 

[John S]

An option is to drill the head with a drill smaller than the threads, then break the head off. Once the head is off there is no load on the threads so the rest should screw out fairly easily.

 

[-bb-]

Maybe try a set of locking pliers...

 

[SELfor50]

On the drilling idea.. what about using an easy out? A small one.
Or is the sump plug too small for that?

 

[s class]

I had this problem on my wife's W202. It has a head taking a standard 13mm spanner. What I did (after trying all the standard butchery techniques) was to grind the had down on two opposing sides until it measured about 10mm across (still 13mm across in the 90 degree direction), and then I got good purchase on it with a plumbers pipe wrench. It looked terrible when it came out, but there was no damage to the sump. IIRC, I hammered on it a modestly as well while applying force with the plumbers wrench.

 

[B13]

I've got the same problem on my 190E, rounded 13mm sump bolt/plug.

Does anyone think its worthwhile hitting it with CRC Freeze-spray to cool it right down and then try to get it out with vise-grips?

Or has this been tried and doesn't work? I'm reluctant to grind if at all possible...

Ian.

 

[Lukas]

Ta all for the suggestions - going to try the pipe wrench first (least chance of accidentally drilling or grinding the sump). Will advise of progress.

I'd suggested several of the same things you guys did, which is reassuring I suppose.

What's an easy-off? Am hesitant to Google it.

Re freezing - the bolt to sump contact would be fairly good, so both things would cool at a similar rate I'd think?

Lukas

 

[John S]

An Easy-Out is a hardened steel type of drill with the opposite thread. You drill a hole in the bolt or plug, select an Easy-Out the correct size and screw it in; it will only go so far in before it locks up and (in theory) screws the plug out. They were readily available once but I haven't used one in years.

 

[BenzBoy]

I believe the travelling Heli Coil man also does the Easy-Out. Of course the following may be a little overkill - http://www.donhad.com.au/Easy_Out_Bolts.asp
Any time I have had a problem like this I have taken my car to my favourite independent who calls mobile service.
Regards,
Benz-Boy

 

[Lukas]

Update: no go with the plumber's wrench, next step is to file some sides back onto the bolt head (the angle grinder approach but with less chance of things going wrong).

 

[B13]

A die-grinder or dremel maybe?

I

 

[WGB]

It's either very tight or you cannot get clearance to use or a decent purchase with a pipe wrench.

I was looking at mine on the bench yesterday and couldn't imagine a sump plug withstanding it as the jaws would cut into the metal.

Are you sure you were using what I know as a pipe wrench?

Any way yes - more Dremel or Die grinder than angle grinder - and please don't catch fire.

Bill

 

[SEL_69L]

Easy Out is the way to go! I had 3 bolts which attached the exhaust manifold to the head in a Skyline. The bolts sheared off flush with the face of the head. There was no way the remains of those 3 bolts were going to be removed with ordinary tools! 3 new bolts were used and the whole assembly is now just fine.

Apparently, the cast iron exhaust manifold and the alloy head with their different thermal co efficients of expansion were easily enough to shear the bolts.

 

[Lukas]

The pipe wrench used was one that looked like these. I can't vouch for how it was used though. Apparently the wrench to bolt head interface area ("purchase") was not great.

 

[WGB]

Yes that's what I was meaning.

Pity it didn't work.

They have to go on the correct way around so that the jaws tighten as you put pressure on them but if it didn't work it didn't work.

Bill