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David Layton
David Layton

Repairing a Rust Hole on the Firewall and tasks along the way...

While we have driven my 73 tii a bit this summer with the revised the ride-height, suspension and wheels tires; the motor was not quite right.  Performance was down and Jacob Marley was rattling the timing chains. 

In late September, my chief mechanic and brother Chris decided for various reasons to pull the motor, drop the sub-frame and transmission.  This was going to give us the opportunity to clean up the engine bay, revise any questionable wiring, totally clean the accumulated oil and grease and make any repairs prior to repainting the engine bay in Atlantic.  This will resolve the issues around painting the engine bay when the car was to be painted this winter.   (The hoist he put in his garage a couple of years back has been a great investment.)

While the motor has been out, the timing chain and oil pump chain and sprocket were replaced; after the timing marks, including the K-fischer pump, were painted in yellow.  We suspect that Scrooge’s late partner was rattling the oil pump chain as there was a full knuckle’s slack and back stagger in the alignment with the oil pump sprocket.  The stagger was from the sprocket which had been attached with the spacer between it and the nut in front causing wear on the back side of the teeth.   Chris found the correct answer on the FAQ, the spacer goes behind the sprocket and the planets were now aligned.

While the motor is sitting on the stand, we replaced all of the Kugelfischer hoses with Ireland silicone items.  Replacing these would have been ‘difficult’ if the motor was in the engine bay.  The Oil pan was in need of paint, so it was removed, stripped and repainted as were the sides of the block.  The oil pan was clean of metal and the crank looked fine.  Crank and bearings looked good, so these were not disturbed. 

We have also attached a new Sanden 509 AC Compressor on a Hobie Dave Bracket.  The AC will be new items under the hood flowing to a Behr Evaporator and Console.  The car had a Frigiking unit with a Sanden compressor that had a packed up clutch on a heavy dealer bracket.  As the Frigiking lines run dead center over the transmission, we are going to seal these up, clean up the metal and paint.  The lines for a Behr run a few inches to the right of the heater box (also being rebuilt).  We are taking many suggestions from Rob Siegel’s book and will use hose fittings on the firewall rather than running the AC lines straight through the firewall.  

Now to what’s behind the curtain where Carol Merrill is standing…..

The old firewall padding was pulled away revealing a rust area above the pedal box that had been partially patched from behind.  There is a bit of surface rust all along the firewall with bits of the foam and glue residue.  The firewall matt has been the perfect sponge to hold water against the firewall for the last 45 years.   I figured that somewhere in the project, there was going to be a rust surprise, here it was.   Left unnoticed it would have been a nastier surprise sometime next year when the pedal box would have begun to flex.
I now know why the engine was so loud.   Pedal box rebuild and shift linkage kits were ordered.  This will also lead to the pedals, pedal box, brake booster and support getting cleaned and painted.

Fortunately, Chris has a 72tii project (0440 – Colorado) which entailed the acquisition of a couple of parts cars.  One of these is a ’74 carburetor that is slowly returning to nature but the piece of the firewall above the pedal box was sound.  So a patch was made with this cut of firewall flank steak and pedal box surround was cut from 16 gauge steel.



And the patch is welded in and primed and surrounded in 3M paintable sealant.
We also put down the sealant in all of the crevices where water likes to collect and sit on both sides.
The sealant excess will be cut away and after it is painted over will blend it and keep the water out of the seams.

Inner Fender cleaned up.  Note the bead of 3M sealant where the inner fender and the frame rail meet.  This was done throughout to eliminate the collection spots.
The Firewall repaired with POR rust converter on the surface where water collected behind the firewall padding.  (In the background is one of the two parts cars.)

Primed Firewall.  The 2 new vertical holes are for the firewall fitting for AC lines.  System will use Behr Evaporator and Console.  Two holes over the transmission were from the earlier Frigiking AC and these will be plugged.    
The Painted Inner Fender.  The garage lighting and the camera flash makes the color appear lighter than it actually is.  In the sunlight, the color compares well with an original Glasurit paint chip book.
Engine Bay ready to sit for at least a week before we start re-assembly.  We have a new factory firewall pad and the various gaskets and clips.  Throttle linkage is being upgraded with one of Harry’s play-less Pull Rods, new return spring and bushings.  This will also be the time to sort out the wiring and add the wires for the new air conditioning.  Other items to tackle before the engine comes back include replacing the parking brake cables and the rear transmission mount.  


02 FAQ Blog on firewall.docx

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