Removing or installing the sight glass nuts on an Olympia machine is no problem with the front plate off the machine....any 17mm wrench will do....but tightening those nuts with the face plate on the machine requires a special tool. This is the wrench we use for this job. Customized from a full size 17mm wrench, the open end is reduced to a fork shape and the box end modified to act as a thin walled tubing wrench. Remove the pstat, and use the box end to tighten the upper and the fork to tighten the lower. Between the two ends of this wrench those hard to get at nuts can always be tightened even with the front plate on the machine....saves a lot of hassle if you just need a touch up.
I always re tighten the sight glass nuts after heat cycling for the final pass through the machine and use this wrench all the time....it can also be used in place of the 17mm for all the other tasks normally done with the standard wrench.
