Low-Air warning

[RBH]

Can any one tell me if a 1953 A40 with factory air brakes has a low-air warning system.  I have been dismantling the truck for a restoration and have yet to see any devises like a light or a mechanism that makes an audible sound. All I have seen at this point is the air pressure gauge located between the engine gauges and the speedo indicating to me that the truck was built with them by Mack.  I will presume that DOT would require such a system if the truck were to run the public highways .  Even if they didn't, I would for safety reasons.    Where would the low-pressure switch be located (in general) if it does have one?

Thanks 

[MHfred]

I do not know about your truck specificly but I would guess it had a wig wag which would have been mounted in front of the driver above the wind shield. When air pressure got low, a red arm would fall giving a warning. School buses had them for a long time and would be a good source for one.

[j hancock]

There is possibility the truck did not have a warning device besides the driver watching the gauge.

DOT then was not like the DOT today.  A lot of old trucking pictures show plenty of bald tires and fenders held on with baling wire.

A low pres. switch installed on the air tank or a firewall mounted air manifold running to a cab buzzer would work or you could plumb a wig wag.  Only problem with a wig wag in front of the driver is that the header trim in an A model is sort of narrow to work with.

I would go for an electric buzzer.

[Hobert62]

9 hours ago, j hancock said:

 

I would go for an electric buzzer.

Same here.   The buzzer is simple, cheap, and easy to hide under the dash out of sight.  

[RBH]

Thanks fellas.