Expert: Brad Sears - 6/23/2009

Question
I had my '66 Oldsmobile Delta 88 with 2-barrel carburetor in to the corner auto shop today to have the carburetor replaced by a remanufactured same model carburetor.  The Mechanic used a socket wrench (not a torque wrench) to tighten down two of the easily accessable bolts.  The other two bolts he used a box wrench.  I was sitting next to the car when I saw him put a lot of twist in the wrench that looked excess (maximum effort).   (I had two years auto mechanics class in High School).  The bolts torque spec says 15 ft/lbs.  Should I have the carburetor removed, a new gasket put in, and then have another mechanic use a torque wrench to apply the correct ft/lbs.?  I'm wondering if over tightening a carburetor can cause damage to the base.  The Lead Mechanic said the reason why the bolts are tightened so much on old cars (at this shop) is to prevent them getting loose and causing a vacuum leak.  That's his reasoning, but he just admitted allowing over-tightening of the carburetor.

Answer
I am glad that what we auto shop teachers imparted to our students has stuck with some. I spent a good part of my work life as an auto shop teacher. Well that said I would do the remove re gasket and torque job. Over tightening especially uneven tightening such as without a torque wrench can distort metal and cause vacuum leaks. Also you could remind the mechanic that there was a device invented several centuries ago that prevented fasteners from loosening. It is called a lock washer. Also the nuts that are hard to reach can be reached with a crowsfoot and the torqued.
Brad