last night I moved the truck, brakes worked fine 100psi or so, honked the air horn for fun, today the air pressure wont build at all. Any ideas? I'm new the these air systems. I wonder if the horn is stuck and letting it all out or if some valve is stuck in the compressor......
Cool truck! I have a 1950 F-8 air brake tractor, as well as a 1950 F-7 Coleman 4X4 (http://www.ford-trucks.com/forums/99...7-coleman.html).
You are fortunate that you don't have "split rims", but the lock ring style that you do have are not 100% safe either. Finding tubeless wheels that only fit 1956-62 F-750 and F-800's as optional equipment will be very difficult. It took me many years to find my 2 sets. You will probably have to have a set made.
You must be leaking air somewhere. The air horn valve could be stuck open, but you should be able to hear the leak.
Compressor was turning, brakes did not seem to work (you can hear the air release when you take your foot off the brake, I didnt hear anything last night, I didnt dare try to drive it) Pressure gauge was at like 10psi or less. I couldnt tell if air was escaping the compressor because it was night and I dont know what the normal sounds of the are truck yet. I'll give it a good inspection on sunday during the daylight. Just wondering if this is a commom problem with a commom fix. Thanks
with any thing that is old you will have repairs to do , and with air brakes any thing that is rubber will rot over the years and most likely when you used it for a short time some thing just ruptured ! could be the brake canisters the diaphragm in them went out , could have rust holes in your air tank , lines could be shot !
Thanks for the replies. I think i'll try to charge the air system with a remote air source in order to hear the leaks without the engine running. I'll have to see if I have the right fittings and try to rig it up.
Ill bet the unloader valves (2) are stuck. If the compressor is the original
style the unloaders are external and need to be sprayed now and then.
Next I would take the air output line of the compressor and see if is pumping. If not the unloaders have to be up (pry with screwdriver) if up
then to to the governor (round thing on left side of firewall) should be a
bendex type O1. Take cover off and move the valve up and down. Up
means no pumping-Its satisfied, Unloader valves will be down. Valve down
Unloaders will be up pumping. Then the next step will be to charge the
system with shop air. Also to note on these trucks the service brake linkage and or valve gets stickey and you gotta pick up the pedal. If this
is sticky just a little (foot valve) it will bypass and exahaust at the bottom
of the valve. I have one truck that does this all the time, and if a driver
does not lift the brake pedal up >all the airs gone. Just another thing for
the old man to fix. Sam
Thanks sam! I had messed with the part on top of the compressor, looks like a rocker arm, and the air pressure began to build again. (coincidence or not, I dont know) Ill check the foot valve too, and all the other parts you mentioned. Thats some great info right there!
Not a coincidence Its the nature of this style with external (rocker arm)
unloaders which should have about .010 clearance. Also I forgot to mention, on the compressor see if it has a dipstick like a lawnmower to
check its oil. It takes regular engine oil. There are about 3 styles they
used like> air cooled self oil lube-water cooled self lubed water or air
cooled engine oil pressure fed. I got no clue what you have, no doubt
it may have been replaced after all the years of service. Myself I
positively despise or hate hydraulic brakes. I trust you still have the
worthless hand brake. Put spring emergencys cans on there and you
will have that extra supply air line for a trailer if you are going 5th wheel.
Napa is just about giving them away. Use 30-30"s good luck sam
#1. Is this how the "VIN" plate is supposed to be mounted ( in the photo below)... in the glove box door with screws? I was expecting those fancy VIN rivets...
By the way, the Engine number begins with 98EQH. anyone care to decode it?
#2. All the documentation I've found says that the GVR of 1948-1950 Ford F8's is about 21,500 lbs single and 37,000 combination. The tag on mine says 32000 lb and I dont know if thats single or combo. I was told by the previous owner that my truck was made from the factory as a dump truck, he said they riveted an extra heavy steel plate on the chassis of only the dump trucks. Thats why I dont know if this one could possibly be 32000 max. single.
For 1950, Ford increased the maximum GVW on all F-8's from 21,500 to 22,000 lbs. Normally, I would have ended my comment there, but your rating plate is very unusual. I have never seen one with a blank area where the GVW could be stamped in. The picture is very blurry, but I assume you are sure that 32,000 is stamped in? If that's the case, then I'm sure the body company (it wasn't Ford) that installed the dump body, and riveted on the fish plates must have done it. They installed the truss under the rear axle as well. Whatever they did, unless they added a tag axle under it, there is no way they legally increased the GVW by 10,000 lbs!
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