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View Full Version : stuck gas tank strap bolts


colo525i
11-25-2006, 06:55 PM
Replacing my crushed and rusty tank, and had both bolt heads shear off as i was removing the straps. I couldn't get them to move with vise grips and as much pb blaster as i could put on them. Drilled out the passenger side one, as i can just put a nut on the back end. The one nearest the tow hook is another story.. It won't budge with vise grips, and there is nowhere to put a nut on the backside if drilled.. I have a tap set is that my best bet?
nizmainiac
11-25-2006, 07:08 PM
this might sound like a bit of a long shot , but seeing as your tank is pretty screwed anyway, why not drain all the petrol out of it, disconnect the fuel lines and fill it with water, that way you can use an oxy torch to heat the nut and expand it, i used to do this on motorcycle tanks to get rid of large dents
colo525i
11-25-2006, 09:30 PM
Tank is out btw, the heads of the bolts came off, and the straps are in pieces. so it is away from the area. Just cannot find anything to grip the stupid remaining stud!
shogun
11-25-2006, 09:37 PM
Look at this pic
http://bmwe32.masscom.net/sean750/engineRebuildM70/Dsc01420[1].jpg
Bolt came out with a screw extractor
http://bmwe32.masscom.net/sean750/engineRebuildM70/Dsc01421[1].jpg
http://bmwe32.masscom.net/sean750/engineRebuildM70/Dsc01423[1].jpg
http://bmwe32.masscom.net/sean750/engineRebuildM70/Dsc01425[1].jpg
http://bmwe32.masscom.net/sean750/engineRebuildM70/Dsc01426[1].jpg
colo525i
11-26-2006, 04:39 PM
Propane torch took care of the stuck bolt, glad i had that tank off, otherwise that'd be a no go.
Tank holds the full 21 gals, but oddly the fuel pump is quite noisy now. I made sure to fill the tank before running the pump at all, so it would not pump air. Pressure seems ok, car runs and accelerates as normal, but what would make the pump go noisy all of a sudden? I made sure the pump was clipped into the piece at the bottom of the tank,so i don't think that is the problem.
Jimbo
11-26-2006, 10:37 PM
Those bolts are one of the worst things i have encountered on this car. Stripped out both the shitty allen heads in about 2 turns. Then I spent about two hours with vise grips slowly backing them out about 1/4 turn at a time, and this is after soaking them in PB Blaster for several hours. I cannot figure out how these things get stuck in there so tight or why BMW didn't use normal bolts that you could actually grip from the outside.

Sorry, just had to vent a bit of frustration:) . I'm glad you got yours out finally.