Ford fu*ked up big time in the design of the plenum chamber of the escort as we all know!Reason being that the drain hole for it sits about 8mm above the plenum floor,so the water was trapped below the bottom of the drain hole, causing the plenum floor,bubble and top of firewall panel to corrode and rust out. As a result, water enters the interior and soaks into the carpet . Result... floors then start to rust out.
A removable bubble is a good idea, but it wont look original, which in some cases will be an issue. When I removed the bubble on my RS2000,I rebuilt the floor of the plenum chamber welding in new metal , the bubble itself was good so all I done was cut out that 8 mm base of the drain hole so no water could collect ever again.I re welded the bubble back on again as original and fitted the drain pipe as normal.Drain pipe still fits as most of the circle of the hole remains, but any water that enters the plenum drains out below it. Problem solved. It also give you enough room to remove leaves and crap( when pipe is removed)
Hope this helps.
Regards,
Liam
