So I got this 52 GMC truck that was all apart when I got it. The firewall has a ton of holes in it. I'm working on the cab, I'd like to know which holes are supposed to be in there so I can weld up the ones that aren't supposed to be there. Also the accelerator pedal pin is rusted in. The pin should slide out from right to left , correct? Trying to understand what holds it in place other than a single cotter pin. Paul
The accelerator pin does slide out from right to left. Mine was rusted in place. I used PB Blaster for about a week and then tapped it out with a punch.
Here is a page from the 47-54 Factory Assembly Manual that I used for my 52 Chevy. I believe its the same as the GMC.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
Don’t remember which way the pin slides, but there is nothing but the cotter pin holding it in place. Soak it down with penetrant like Liquid Wrench or Kroil, then you should be able to tap it out.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
The pin can only come out from the left. The hole in the right side of the bracket is not round. That is where it is likely rusted tight. It is a snug fit when new.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
Only cavemen still weld firewall holes. Cut to size patches for all the holes, rough up around the holes on the inside of the firewall with 36 grit disc, rough patch up with 36 grit, butter around holes with 3M Panel Bond and stick patch in place. Next morning your DONE with no warping and about two hours total time. Panel bond holds together airliners and the 2000mph SR71 so it should be sufficient for firewall holes.
Evan, can I assume your making the patches bigger than the holes, bonding, then then filling the front with bondo?
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
Yes, patches are bigger but zero chance of rust since panel bond squishes out all around patch. One can even used the panel bond as a filler since the firewall is only .060 thick.
3M panel adhesive is wonderful to work with as Evan has described. It is like butter to work with, sets up hard, but sands out smooth as glass. Its a little pricey, but so is welding and fixing warps.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
You can also use JB Weld's "Quik-Weld" in the same way if you are on a budget. It sets up faster and sands smooth also. Hold vertical patch pieces in place with common masking tape until the JB Weld is cured. I used the regular JB Weld to repair the seam between the roof and pillar on my 1952 40 years ago and still have no problems.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Yes, any two part epoxies will work. We have a case or magnets for holding vertical patches. My rating is: Best---Marine Tex (expensive) 3M Panel bond (designed for the job) JB Weld Here is a shot of a Model A Tudor that the soft top replacement panel was Panel Bonded in around 2005. Has been street driven since then and still zero flaws at the bonded joint.
