I'm new to the 1940 Special Deluxe, its been sitting for years and I'm going thru the brakes, replacing tubing, hoses, wheel cylinders and ran straight into a wall - how do I get the Master Cylinder out? Theres this other gizmo connected to the transmission that I can't fathom and its right in the way not mention the pedals seem to pivot in the Master Cylinder, I just can't get my head around it. I looked for an access panel in the floor but there isn't one. Am I missing something? how do I get the M.C. out?
I have the Chevrolet 1940 Service Manual coming but it won't be here until next week and I've got my hands dirty now and want to get things done.
Can somebody explain to me what all I'm looking at?
Thanks, Oj

The gizmo you are looing at is the vcuum power gear shift cylinder,
Master cylinder has two bolts holdingit on to the frame member.
Is the car a convertible? That master cylider is more difficult to get at duue to the X frame.

This is for 41-48 but I assume the 40 is similar, if not disregard. In addition to the tubing and the two bolts Gene mentions, the lower halves of the pedals usually need to be removed from the master cylinder prior to removal. Disconnect the upper halves of the pedals under the hood on the face of the firewall. On the front of the cylinder where the lower pedals rotate, there is a plug. Remove the plug and there is a retainer in the hole. The retainer is tapped to screw in what I believe is a #10-24 machine screw. You can use the screw to pull out the retainer. Once removed the lower halves of the pedals will slide out of the master cylinder. Mike

Here is a link to the online service manual. Doesn't show the 40, but the 39 or 41 should work.

http://chevy.oldcarmanualproject.com/

1939 is different,,,1940-1948 the same.

Thanks guys, when I quit last evening I was trying to figure out what that plug was intended for in the front of the M.C., I had pulled the screw out for a looksee and ran it back in before I lost it, I thought it was some kind of adjuster that I'd have to deal with. I'll get back on it this morning.
So far I have found 5 snake skins, what gives me pause is that if they aren't in the car they must be in my shop.

Well, it is out and on the bench, thanks again. Now to dig into it, it is a mess, I hope the cover screws will yield.

....and where are the snakes???

I pretend they dropped off onto the rollback that brought the car and he can deal with them!

Ah! Yep! I hope for your sake one wasn't having a sleep when the rest decided to drop off onto the rollback!

Believe me, when I open the shop in the mornings now I make a lot of noise and rattle stuff around before I even get close to that car, I kinda creep up to it and shine a light into the engine bay to see if anything is in there moving around.
On an more positive note I have the MC out and disassembled. It was a mess, but very rebuildable, I media blasted it and have it in primer now. That little pressure release hole was totally crudded over, I ran a .028 drill bit thru it by hand to reopen it. A couple of the linkage bars need to be replaced and some of the non-bushed bolt holes are too wobbly now, I'll resize them back to stock with bushings. I don't think I'd be overly critical but there is factory level crude engineering on this car.