The metal flap on the outside dryer vent cap completely rusted shut over the winter, meaning the laundry heat was trapped inside the pipe line. If the exhaust air can’t escape, the dryer starts overheating and becomes a total fire hazard. Picked up a standard heavy duty plastic louvered cap from the store to swap it out.
The old metal hood was practically glued into the exterior brick wall with thick layers of ancient, hardened caulk. Trying to pry the metal flange loose with a flathead screwdriver just stripped the plaster and made a giant mess of dust. Had to use a heavy hammer and a cold chisel to break the old seal away, which took forever just to get the wall sleeve to budge.
Once the old cap finally popped out, trying to slide the new vent pipe through the narrow wall opening was a major struggle. The brick hole was packed with old debris and jagged mortar edges that kept catching on the new plastic edges. Had to use a wire file to manually grind down the interior stone border until the sleeve would actually slide in flush against the house.
Ran a thick bead of exterior silicone sealant all around the new plastic flange to keep the rain out. Screwed the frame directly into the masonry anchors and verified the flaps swing open easily when the air hits them. The exterior vent cap is fully replaced.