The Stovebolt Site Forums The Shop Area Engine Shop Accelerator pedal sticking on 235 in '51

I've got a problem with my gas pedal sticking/hanging up, and after installing a new accelerator return spring, which I was hoping would solve the problem, it's just worse. I've had this truck for about 10 years now, and it's always been a bit funny in this area. Although it wouldn't stick all the time, I had gotten use to flipping it "unstuck" with the edge of my boot, to the point it was almost an auto response. It didn't stick all the time, and maybe not even most of the time, but it did, no matter what I tried. WD 40 at the floor board hole, spraying PB Blaster all over the linkage connections, etc.

So when I ordered some parts last time I went ahead and ordered a new return spring from classic parts. But now that it's on, it sticks everytime, and I'm fed up with it screaming every time I engage the clutch and pull my foot off the gas to switch gears.

One problem I'm noticing after fixing a stuck heat riser valve I finally got freed up this summer is that the down rod linkage from the carb to the pivot arm is so close to the flange of the intake/exhaust manifold connections, it's almost (maybe it is) rubbing. Let me say that this is a 235 engine in a '51. I bought it this way and it was my daily driver for about 7 years, so although it's sticking and not releasing now, it has worked well enough during that time, until now.

Is it possible the spring I got from CP isn't strong enough to pull it back? (anybody had that problem with one of their springs, I mean). I will say that the spring on it before was neither the correct spring nor was it attached at the correct points. (I had to order the tab that bolts on at the oil pan to hook it up the right way). Or is there something up with the linkage that I'm not thinking of? I've got both manuals for it, and with everything lubed up as well as I can get it, what is the normal troubleshoot for this? Thanks for any help on this problem. Lee

Take a look at every place a rod end goes through a hole, and the pivot point where the do-hickey attaches to the side of the block.
It would be best to remove everything from the truck so that you can carefully inspect for wear.
There are many pivot points on the gas pedal linkage assembly. If you have some wear on all of those points, they can add up to a lot of resistance in the pedal returning.
You may want to remove the spring and move the gas pedal up and down to see if the rod is passing through the toeboard for the full travel without dragging on the toeboard.

Make sure the carburetor itself is not binding up. Remove the linkage and cycle the carburetor butterfly several times. If ok then work backwards from there.

Look at the rod where the spring attaches. Is that where it hangs up? Next, which intake manifold are you running? The casting # is on top in front of the carb. See if you have a 3754644 low rise manifold.

Ok, I found the problem. Thanks very much for the replies. Jethro, the number on the manifold is '3838922 GM'. What's the difference between low rise and mine? How would it make a difference, I mean. JHA- The carb is free. It's been lubed so many times in the last year while I was trying to free up my heat riser valve, it's like snot on a glass door knob. But here's the problem, and I was aware that it was here, but until I installed the new spring and mounting tab, it was never really a problem. I'm now thinking that whoever rigged up the last return spring must have been trying to fix this severely ignorant problem.

I'm not sure if the flange on the exhaust pipe was put on by my (former) muffler guy, or if he just transferred it from the old one, but it's absolutely an error I need to fix as soon as I can. The flange is for something a lot bigger than my manifold flange, so now that the spring is heading downward instead of back to the firewall (actually, more like down to the pedal assembly area) it's not bringing the rod away from the flange, which is causing some serious friction at that point. I guess it was still too close before the spring change, because I've had occasional problems with it for years. I'm now thinking that this all started when I had the new exhaust put on not long after I bought it. Now that I think about it, it was never a problem when I bought it and for the few months I had it before I had a new exhaust put on it. So for all these years I've been fighting a problem that the muffler shop handed me. And I can't even go back and complain. The guy retired last year and sold his shop. Oh well, at least it's fixable and I can quit the pedal kicking soon. Thanks a lot, fella's, for the suggestions. Jethro, I'd still like to hear about that manifold, though. Thanks again, you guys. Lee

The design changes of the 235 that necessitated the lowering of the waterpump etc due to the lower hood designs of the '55 and up GM vehicles also created hood clearance problems for the intake systems. 3754644 was a partial solution as the heat riser box (which the carb bolts to) was lowered giving the oil bath air cleaner clearance with the hood. Dropping the carb lower created clearance problems with the carb linkage. A new linkage was designed to deal with that. I had installed the 4644 on my 54 3100 (57 235 rebuild) and couldn't get the old linkage to work without hanging up. I walked over to the '57 6400 261 to have a look and it also had a 4644. Took the linkage off and it worked perfectly. Compare the pic with your set-up and see the lower carb mount and dog-leg linkage.

Ok, I can see what you're talking about now. The "neck" is shorter, and the linkage is definitely formed around everything. I tried to post a couple of pics, but my old photo storage place went out of business, and I forgot I couldn't just pull them from my computer on this site. But where your manifold/exhaust pipe flanges meet, the flange on my pipe sticks out over 1/2" to the right of the manifold's flange. They actually had to elongate the bolt holes toward the inside to make the manifold's bolt holes to line up with them. Really an ugly fitting. I wonder where I can find an exhaust pipe flange that will fit this? Guess it's time to start searching the parts catalogs! Thanks for that pic and explanation, Jethro. That is interesting. Also, like so many others on here, you're engine compartment makes me ashamed of myself for not cleaning mine up to that level. But one day, after we get moved into the place we intend to build next summer, I'm going to restore it completely.

You can “just pull them from your computer” by following the instructions in the left margin of every page.

It's not that clean... I put too much oil in the breather and when I took it for a 3 mile run it puked out all over the place. Wiping it off made everything nice and shiny...

Thanks, JHA! Didn't know that was there. Let's see if I can do this.

Perfect, you got this whipped!