AMT Ford C 900/Garwood LP 900 refuse truck

[Eric]

Brian the governor was a strictly mechanical device with mechanical linkage to the carburetor some may have had an electrical solenoid operated control to step up idle RPM

For PTO operations

In the picture of the back of that engine the electrical sending units you see below the governor are oil pressure sending

Units for the oil pressure gauge, maybe an idiot light and possibly a kisor system which would shut down engine in the event of a

No oil pressure or over heat condition ( these systems used to be common before electronic engines.)

For electrical to the rear of the truck there may have been work lights at the rear of the truck as well as things like a two speed rear end or differential lock which could be electrical solenoid operated.

Hope this helps 

Eric

Edited January 19 by Eric

[Brian Conn]

  First off , huge thanks! 

Here is what has me stumped w/ the engine governor...........I've blurred out the rest of the engine so as to focus on the governor itself......

Notice the very top of the governor....there is a cable that has a threaded end the screws onto the the governor.

This picture shows the cable attached to the governor.....from what I have seen with the other Ford truck  engines, it goes over to the Left side of the engine area and disappears,  It's that cable that I need to know where/what it goes to....I have everything else with the engine figured out,this is the last piece of the puzzle that is holding me up

 

[Brian Conn]

  Since it warmed up to 16`f I decided to do an outside picture..... 

  This shows the air tanks a little bit better as well as the correction that I made to the fuel tank by moving the fuel line back to the rear fittings and adding a line to the sending unit and running it back to the cab area.  

 

 

[Eric]

Brian 

Sorry I didnt get back to you earlier we've been on the road .

The cable you show on top of the governor is a mechanical tachometer drive cable very much like a speedometer drive cable.

[Eric]

Brian 

On your air tanks they would have been set up with two air tanks the first one would be a tank with a centre separator effectively making it two tanks in one.

In this center divider wall there would be a check valve the air from the compressor would be pumped into this first tank was known as the wet tank where the moisture in the air would collect as that compressed air cooled.

Each tank would have a mechanical drain cock to dump any water collected . The wet tank would not have any air lines running away from it as it was only used as a wet tank the other half of that tank was referred to as the primary tank this tank would be used to operate  half of the brake system we'll say the front brakes so there would be an air line running up front to the treadle valve.

From the primary tank there would also be an air line which ran from the primary tank to the secondary tank this air line would have a spring loaded check valve known as a priority valve it would allow the primary tank to pressurize to 70 psi before it would allow any air into the secondary tank this was done to separate the two brake systems front and rear so if an air line where to blow or be severed the other tank would still have air to operate it's related brake system.

The secondary tank  was used to operate the rear brakes and as such had an air line running to the treadle valve as well.

From the treadle valve there would be at least two air lines one running to the front brakes and one running to the rear brakes .

The front brake supply would have a QR ( quick release ) valve in line to aid in dumping air on brake release to speed up the brake release.

The rear brakes may have been the same way or which was more likely the case would have had a relay valve close to the rear axle/s this valve was sometimes mounted right on the secondary air tank next to the axle , the object here was to feed enough air supply to the rear brakes to run as many brakes as there are axles brakes at a faster rate.

This secondary air supply to the treadle valve would also be used to supply air to the yellow parking brake valve on the dash  this valve was pushed in to release the parking/ spring operated brakes and was setup so that in the event of air pressure lose the ( below 60 psi the valve would pop out and dump the air off the parking /spring brake chambers which would allow the springs brake chambers to apply the rear brakes.making the system fool proof.

This valve as mentioned would be either feed from the secondary tank directly ( screwed into the air tank or by a larger air line this relay valve would also have an air line which is run from the treadle valve as a signal line to operate the relay valve the relay valve would also have a QR valve built into it to speed brake release for the rear brakes as well.

The only other line connected to the secondary tank would be for accessories like air suspension,air wiper motors,air horns etc this air supply would be connected to another priority valve screwed into the air tank which would maintain 60 psi in the secondary tank in the event of a major air leak in any of the accessories.

If the vehicle had air suspension it would likely have another air tank feed by this supply.

There would also be a smaller air line from each tank one primary and one secondary these would run directly to the dash to operated either a dual all in one air gauge or two air gauges on the dash.

Hope this helps

Eric

Edited January 26 by Eric

[Gary Chase]

13 hours ago, Eric said:

Brian 

On your air tanks they would have been set up with two air tanks the first one would be a tank with a centre separator effectively making it two tanks in one.

In this center divider wall there would be a check valve the air from the compressor would be pumped into this first tank was known as the wet tank where the moisture in the air would collect as that compressed air cooled.

Each tank would have a mechanical drain cock to dump any water collected . The wet tank would not have any air lines running away from it as it was only used as a wet tank the other half of that tank was referred to as the primary tank this tank would be used to operate  half of the brake system we'll say the front brakes so there would be an air line running up front to the treadle valve.

From the primary tank there would also be an air line which ran from the primary tank to the secondary tank this air line would have a spring loaded check valve known as a priority valve it would allow the primary tank to pressurize to 70 psi before it would allow any air into the secondary tank this was done to separate the two brake systems front and rear so if an air line where to blow or be severed the other tank would still have air to operate it's related brake system.

The secondary tank  was used to operate the rear brakes and as such had an air line running to the treadle valve as well.

From the treadle valve there would be at least two air lines one running to the front brakes and one running to the rear brakes .

The front brake supply would have a QR ( quick release ) valve in line to aid in dumping air on brake release to speed up the brake release.

The rear brakes may have been the same way or which was more likely the case would have had a relay valve close to the rear axle/s this valve was sometimes mounted right on the secondary air tank next to the axle , the object here was to feed enough air supply to the rear brakes to run as many brakes as there are axles brakes at a faster rate.

This secondary air supply to the treadle valve would also be used to supply air to the yellow parking brake valve on the dash  this valve was pushed in to release the parking/ spring operated brakes and was setup so that in the event of air pressure lose the ( below 60 psi the valve would pop out and dump the air off the parking /spring brake chambers which would allow the springs brake chambers to apply the rear brakes.making the system fool proof.

This valve as mentioned would be either feed from the secondary tank directly ( screwed into the air tank or by a larger air line this relay valve would also have an air line which is run from the treadle valve as a signal line to operate the relay valve the relay valve would also have a QR valve built into it to speed brake release for the rear brakes as well.

The only other line connected to the secondary tank would be for accessories like air suspension,air wiper motors,air horns etc this air supply would be connected to another priority valve screwed into the air tank which would maintain 60 psi in the secondary tank in the event of a major air leak in any of the accessories.

If the vehicle had air suspension it would likely have another air tank feed by this supply.

There would also be a smaller air line from each tank one primary and one secondary these would run directly to the dash to operated either a dual all in one air gauge or two air gauges on the dash.

Hope this helps

Eric

That is some great info and explanation, going to print this out. Question: I have seen an air tank for each rear axle, 2axles, 2tanks, 4 axles, 4 tanks. As I understand these where for air brakes and air suspension?

[Eric]

Yes the extra tanks where to make sure there was enough reserve air for multiple brake applications and in the case of vehicles which were used off road such as logging trucks they where common to have more air tanks dedicated to the suspension systems one per axle to help with the extra air usage by the ride control valves over uneven terrain the alternative to this was to use ride height valves with a damper to slow their reaction time to changing ride height. Remember that air suspension was considered an accessory and would only receive air after the brake air tanks where filled above 70 psi requiring separate tanks to maintain the separation .

On trailers such as  a low boy it was common to have dump valves to lower the deck for loading ,these systems often used larger or more air tanks with relay valves and larger air lines to the air bags to help speed the recovery of ride height when loading was complete as this operation would use more air volume than could be supplied from the tractors air compressor quickly .

[Brian Conn]

   Finished up the rear axle.....

 Huge thanks to Driptroit 71  He did a post at Modelcarsmag.com forum in regards to different types of truck air brakes  https://www.modelcarsmag.com/forums/topic/175424-different-types-of-truck-air-brakes/   I used some of his pictures for reference on this build.