Removing Freeze Plug - secrets???

[rogerh113]

Hi,

In the last phases of installing the heat exchanger, and having an impossible time removing the freeze plug adjacent to the injector pump.  I've applied penetrating oil liberally, waited, and then applied my 27mm hex key (with added leverage), and it won't budge.  It is pretty clean looking (only been in for a few years).  Are there any secret approaches to getting this guy loose??  I plan to continue to apply the penetrating oil hoping over time it will break down whatever is locking this guy up.  I believe the plugs are designed to bind in the hole - hopefully it is not permanent.  I am concerned about stripping the hex hole in the plug if I apply too much leverage, and then really being up the creek......

Any suggestions appreciated

Roger

[ctaylor738]

When you say "leverage," what do you mean?  I use a 3 foot length of pipe in such situations.    There is a lot of metal-to-metal cotact, so you can apply a lot of force as long as you can keep the hex bit straight in the hole.

The other technique is to heat the block with a propane or welding torch.

Chuck Taylor
107 Addict
Falls Church VA

[rogerh113]

Yep, a 3 foot length of pipe is the leverage I am talking about.  Part of the problem may be that the hex key twists a bit, making it impossible to keep it straight.  I am looking now for a 17mm hex bit (1/2" drive) that I can use with my long handled torque wrench.  I am thinking that having the rotational stress centered on the bit may keep it more centered than the hex key.  That plug is really in there - the car is shifting around with the stress of the pipe, but not that plug. No access for the torch unless I take out the injector system - at some point (well before that) the heat exchanger will end up not being installed.

Any good 17mm bit sources would be appreciated - looks like one more useful, but hard to find, tool.  Seems like mail order may be the only route (guess it gives the penetrating oil a few more days to make an impact).

Regards -- Roger

[66andBlue]

quote:Originally posted by rogerh113
... Any good 17mm bit sources would be appreciated - looks like one more useful, but hard to find, tool.  Seems like mail order may be the only route (guess it gives the penetrating oil a few more days to make an impact).

Roger,
there are always some for sale on eBay. Right now check item #s 260006031199, 160004885724, 170005716042.
Also have you tried "PB Blaster" (http://www.pbblaster.com/store/moreinfo.cfm?Product_ID=1) to loosen the plug? You can get it at any O'Reilly automotive supply store.

Alfred
1966 blue 230SL automatic

[rogerh113]

Thanks - just purchased one of the ebay offerings (how can you miss from a seller called 'benzguy'??)  Wonder if PBBlaster is any different than the other penetrating oils??  I've been using some by Gunk/Liquid Wrench that touts the same thing - can't say that it has helped much in my situation, but maybe it is not a fair test........  

Regards -- Roger

[psmith]

Hi Roger,

Several here on the list said that PB Blaster is more effective than the others.  I can't say for sure, but since my can of Liquid Wrench was about 30 years old, I bought some Blaster at the local Kragens.

Pete S.

[rogerh113]

Well, Kragen's is just around the corner, and 4 bucks is cheap if it helps get that plug out.....  

thanks -- Roger

[ctaylor738]

PB Blaster and Kroil Aircraft are the best for this.  You can get a 17mm hex-bit socket off the Matco or Snap-On trucks or at Samstag Sales on the Web.

Chuck Taylor
107 Addict
Falls Church VA

[Naj ✝︎]

Hello Roger,
I tried everything you've tried except heat. :oops:
In the end I drilled 20 to 25 3mm holes round the circumference of the plug and eventually broke it up with a chisel.
Be careful not to drill the block !!

naj

68 280SL

[ejboyd5]

Make an effective 17mm hex driver using a 10mm bolt and several 10mm
nuts jammed together.  When assembly is complete simply insert it a 17mm socket with the bolt head protruding and, presto, you have a 17 mm hex driver - much cheaper than Snap-On.

[rogerh113]

Thanks for the suggestions.  The hex driver turns out to be about $10 delivered, so not so bad - I can also use that on the drain plugs for the Mercedes and BMW, so not a one-time shot.  I imagine the snap-on version significantly more dear.

Has anyone tried using some of the freeze spray sold at electronic stores to cool parts??  Perhaps instead of heating the block (expanding the hole size) I can cool the plug (decrease the plug size).

[ctaylor738]

Yes, the chiller spray does work, at least on smaller bolts.  In fact there is even an official MB part that combines a chiller with penetrating oil.

Chuck Taylor
107 Addict
Falls Church VA

[Raymond]

The NAPA store here had 17mm hex drive bit in stock when I went looking.

Ray
'68 280SL 4-spd Coupe

[rogerh113]

Thanks for the tip, and I will look at Napa for tools next time (already ordered a 17mm hex).  All the other auto/hardware stores had 10mm as their largest, so I figured it was one of those obsure tools nobody actually carried in stock.  Considering how many cars have 17mm plugs on them I am surprised the hex bit is not more available (of course, I guess not that many people work on their own cars anymore......)  

I'll post an update when I get the 17mm bit and try and dislodge the plug.  Giving it liberal doses of PB Blaster while I await my bit!!

Roger