Hello Trying to change a combustion blower of this old 25-PDVC ! ! ! Actually it is not that old MFG date is 12/07 but being ousted to a garage used by cold wet vehicles may not have helped. Sanding and painting the door and firebox worked out well and I put in a new convection blower whether it needed it or not! A new 3/4" graphite impregnated rope door gasket also gives it a new spark! The combustion blower seems to have gotten the bad end of the stick! LOL Wow just a little rusty! See pics. With some PB blaster and wire brushing, all of the exhaust blower housing bolts came out except the one closest to the back. When I started rounding the bolt head, I knew this was not getting easier! ! ! LOL Tried some heat with the MAP gas but no way Jose! Could not get any pressure from the lock washers to turn it, since after they started to grab, they would pop right off! Now what? I could not get the drill in there with normal titanium drill bits, I scooted over to Home Depot and purchased a titanium quick change drill bit set for $20. Luckily not very expensive. Got the 1/8" drill bit into the bolt head and after drilling for only a minute, POP! The bolt fell out and the whole blower dropped off! Yeah! I zipped down to the local hardware store for a M5-0.8 Stainless Steel bolt upgrade with washers to mount the new blower housing. While it was all apart, I wire brushed the exhaust plenum, vacuumed it out and then did the Dry Moly spray. Also I gave the new blower blades a little squirt with the Dry Moly too! I had to insert a larger screw in the hole that was drilled out, The screw used was like the screws used on the exhaust blower cover panel only stainless steel. It worked. How does it look? I will be testing it soon. Pic 1 - Quick change 1/8" drill bit thru bolt head Pic 2 - Old rusty blower Pic 3 - Shows big hole in exhaust flange! Pic 4 - Exhaust plenum cleaned and coated with Dry Moly spray Pic 5 - New blower with Dry Moly on fan blades Pic 6 - New blower motor Pic 7 - Stainless Steel upgraded bolts and washers next to original screws Pic 8 - new exhaust blower installed Click on pic to enlarge and see slide show.