Technical Mystery vacuum switch/button on lower dash of 1947 Fleetmaster

Found a vacuum switch or button in the lower edge of the dash - wasn't connected to anything. My '47 Fleetmaster does have windshield washer nozzles in the cowl, but everything else for washing is gone. Was there a vacuum-operated washer pump, or was this for something else???? Thanks!

 

Hehehe! Loved that response! Say, does the presence of a nitrous button mean the crank was drilled and the rod bearings are pressure-lubed now? Hehehe! Seriously, I'm new to cars this old.... And ignorant.....

 

vacuum starter switch

 

I just helped do an engine swap on a '48 Fleetmaster, and it had an aftermarket horn/whistle on it that was vacuum operated.

 

I am assuming some aftermarket gadget, maybe wolf whistle? I had a 46 and a 48 that did not have switch of that type under dash.

 

Pretty sure an add on for a wolf whistle or oil eye or maybe a vacuum operated fan ?

 

Chevys of this vintage may have used a vacuum actuated shifter. I don't know if any of this vacuum system was located under the dash or if it was all under the hood and floor panel. I think it was pretty common for them to be converted to a direct linkage shifter.

 

Not sure about Chevys, but back a little earlier there was a vacuum shift two speed rear end , mostly for Fords. Maybe? But I’m betting on the whistle!









Bones

 

the vacuum shifter stuff was all self contained at the transmission, it did not require any buttons to make it operate. The windshield washer system used a button that was in the wiper knob, or a separate one on the floor. But that was for the Chevy accessory...there could have been an aftermarket washer that had a separate button like that.

 

Most likely for a wolf whistle or air horn. They did make vacuum operated trailer brakes but the control lever was different than that. Not a button but a lever.
Vacuum shift was standard equipment on Chevies from 1941 to 1948 but it was entirely self contained and worked automatically. When you moved the shift lever it opened a valve to a vacuum cylinder that assisted in shifting gears.

 

Someone told me some GM cars had a thingee sucked the ashes from the ash tray .

 

I'm not sure what it was originally for, but I ended up with the same button. I think it was in a 47 Ford I had, but not connected to anything.

 

You are correct, and there is at least 1 Youtube video about this fascinating shifter. The claim to fame was that the lever of the column shifter was shorter, having less mechanical advantage than the longer floor shifter. Cool old video. My car doesn't seem to have any remnants of the vacuum shifter, except maybe a vacuum tap sandwiched between the carb and manifold. I'm starting to wish for vacuum assisted steering!

 

When they went to column shift from floor shift they made a short shift lever convenient to the steering wheel with a short throw, and to make it easier to shift added the vacuum assist. On later models they made the lever longer and the throw longer for more leverage and dispensed with the vacuum cylinder. There was a kit to change them over, if you just take off the vacuum cylinder they are hard to shift.
About the steering, may I suggest you go over the front end, repair or replace any worn parts and have an alignment done? Your shocks probably need to be filled with oil too. Use hydraulic jack oil. To complete the job have your wheels trued up and tires balance, you will think you are driving a new car no kidding. Others have followed this advice and it took away all desire for power steering, suspension swap etc. at a fraction of the cost. Your car was easy to drive when new and it can be again if everything is put right.

 

Us Ford guy think that, as a rule, Chevys really suck. That vacuum button just allows a Chevy suck even more

 

Hehehe! Understood!

 

I had to get the front shock/upper control arm assemblies rebuilt - one had about 1/2" of lost motion in the fore/aft direction at the top of the king pin - most likely internal pivot bushings worn from years of driving with an out of round or out of balance tire. Replaced king pins, thrust bearings, and bushings - including the threaded bushings and link pins. Replaced the tie rod/ends on the passenger side and the tie rod ends on the driver's side - also because of lost motion. Rebuilt the steering gear and replaced the worm shaft tapered roller bearing that was bad and cleaned up the inner race (this is made onto the worm gear - not replaceable singly). Replaced the balls in the sector shaft roller because of rust. Cleaned up the rusty and pitted worm gear, but really needed a new one. Because I cleaned up the worm gear, I can't quite get all the lost motion out of the steering gear, even with the worm adjusted as near the sector roller as possible. Had to replace all the rims, as water had entered around the valve stems and rusted the old rims away. However, I appreciate the input about steering effort possibly still being greater than it should! One possible cause is that the tires are wider than original - not real wide, but a standard 16" modern radial tire easily obtained - maybe this was a mistake. I'm not a big fan of power steering, but I wonder if I can find a modern manual steering box with a sector gear (instead of roller) and recirculating balls that will work for this application - I would prefer this to buying new parts for the old gearbox. I do like the big steering wheel! I am certain the car is safe to drive, but could be improved. This is a low-budget build, and so far the rebuilding of the front shock/upper control arms was the greatest single expenditure. Front end kit with bushings and link pins was 2nd, and rims were 3rd. I've also replaced all the brakes lines, shoes, master and wheel cylinders.

 

Just a little good natured ass bustin'.
Actually, at 17, (1969) my first hot rod build was a '48 Chevy Coupe, 283, 3spd, 57 rear.

 

You don't mention getting an alignment, other than that it sounds like you did everything right. When new your car was easy to steer and to drive. Not up to sports car standards or modern car standards but easy and pleasant within its limitations. Pumping up the tires to 32PSI helps.

 

Nice hair.

 

Northing listed in the 47 accessories that would go with it pages (gmheritagecenter.com) I'd go along with a vacuum operated aftermarket accessory.

 

Back then I was a pot smoking, beer drinking, long haired hippy with a loud obnoxious hot rod...pretty much "checked all the boxes" for the local cops

Prom pic...


Nowadays, I'm a cigar smoking, beer drinking, long hair (ponytail) old fat guy with a loud obnoxious hot rod.

 

You caught me! I hate having other people work on my car, and have a hard time imagining that an alignment guy would take the time to do a good job when turning the link pins affect both caster and camber at once - especially on a car that looks this bad. I made a toe-in checking device several years ago, and used that, and studied the old Chevy manual for the caster and camber. Camber is pretty straightforward, but the caster is determined by measuring the change in the angle of the spindle while turning the steering knuckles from 20 degrees left to 20 degrees right. I'm least confident in my estimation of the amount I turned the steering, but I believe I got it close. Caster is such a small angle anyway, I figured having the steering turned more or less than 20 degrees would have minimal impact on it. I did successfully adjust it! The car rolls easily - I can push it in or out of my garage when I need to. Although the tires and rims on it now are average width, they are a lot wider than the original tires/rims. I drove about 30 miles today, and everything seems to be in order with the alignment. Maybe when the car looks better, I'll find an alignment shop that knows about link pins and such.... I was surprised when I found this car had IFS and coil springs - I was expecting a solid axle and leaf springs! And it has overhead valves, too!

 

I don't know what it's for either but I have one like it too......and I once had a 48 chev coupe. I think it's for vacuum operated windshield washers because it allows vacuum to pass only while the button is pushed...let go and the vacuum stops.

 

Sounds like a good possibility! My car had a bracket on the firewall that looks as though it might've held some sort of bottle - maybe that was the reservoir. Haven't researched washers yet - getting the old girl going - and logged about 30 miles today! Every time, I hit a bump, she loses another 5 pounds in rust flakes.....

 

You know, that car looks totally different with the bumpers removed!!!!!! It's awesome!

 

If it's anything like mine, the vacuum wiper valve (the one on the dash that looks like an afterthought) leaked like a sieve, and someone probably by-passed it and put a simple on-off valve. My oil-filled shock absorber/top wishbones had the same problem, when I first got the car, I poured the oil in at the fill plug, and it came out of the worn shaft seal/bearing , just as fast. Not wanting to sell a kidney to overhaul these, I put external cylinder shockers on, and am getting an IFS ready to install.

 

I had an old pontiac that had a canister under the hood for ashes and cig butts - it was activated by a vac. button and had a small chrome port on the bottom of the dash that you flicked your cig ashes at it and the vac would suck them into the canister - just a thought - Jaxx

 

I'm with you! This project has been full of issues that almost merit big changes. I'm still replacing 6V accessories (most lately the turn signal flasher) and wishing I'd started out with a 12V conversion! Always on the tipping point.....And yes, the afterthought wiper switch does leak - but I found I can stop the leak by moving it back very slightly toward the "run" position. The heater control in my '84 pickup is the same way - and both are made of pot metal....