doubleclutchinweasel
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Status Replies posted by doubleclutchinweasel
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I have a treadle valve leaking air. 3 years ago I changed the original treadle valve out. And ran the truck for 2 summers. The new one started losing air thru the bottom. I changed this one out also because the reservoir holding the air brake anti-freeze & rust guard was empty. Thinking the valve got contaminants in it. But this 3rd valve is leaking air also. I changed out both check valves that did not help. This is a 1978 U600 single axil dump truck.
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Not sure if your unit has a single system or a dual system. Older ones had a single air system. Air went from the wet tank to the dry tank and then to a single point on the treadle valve. Newer stuff had a dual system. Air was split into 2 separate systems so that, if one system failed, the other would still operate. I think those used a different treadle valve setup. I think those were split front/rear. Those dual systems were a little after most of what I had experience with.
There shouldn't be a difference in air pressure between the wet and dry tanks.
Here is a Bendix chart showing a typical dual system. I can hook you up with their troubleshooting guide (see link).
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I have a treadle valve leaking air. 3 years ago I changed the original treadle valve out. And ran the truck for 2 summers. The new one started losing air thru the bottom. I changed this one out also because the reservoir holding the air brake anti-freeze & rust guard was empty. Thinking the valve got contaminants in it. But this 3rd valve is leaking air also. I changed out both check valves that did not help. This is a 1978 U600 single axil dump truck.
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I have a treadle valve leaking air. 3 years ago I changed the original treadle valve out. And ran the truck for 2 summers. The new one started losing air thru the bottom. I changed this one out also because the reservoir holding the air brake anti-freeze & rust guard was empty. Thinking the valve got contaminants in it. But this 3rd valve is leaking air also. I changed out both check valves that did not help. This is a 1978 U600 single axil dump truck.
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There are only a few ways air could get to the treadle. First thing to do might be to block the main supply line coming to the treadle. If that stops the leak, it probably is another bad treadle valve. If there is still air coming out, you could then try to see where it is coming from.
You eliminated the parking brakes leaking through, so that's good. In some systems, there is a line connecting the yellow valve to the delivery side of the foot valve. This is an anti-compounding setup. If air were to leak past the yellow valve, it could exhaust through the foot valve.
If changing the foot valve has corrected this issue in the past, there is a good possibility it will correct it again. Then the question becomes why the valves keep dying on you. One of the biggest culprits is oil in the air system. That tends to kill the seals in the valves.
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I have a treadle valve leaking air. 3 years ago I changed the original treadle valve out. And ran the truck for 2 summers. The new one started losing air thru the bottom. I changed this one out also because the reservoir holding the air brake anti-freeze & rust guard was empty. Thinking the valve got contaminants in it. But this 3rd valve is leaking air also. I changed out both check valves that did not help. This is a 1978 U600 single axil dump truck.
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Is it POSSIBLE that air is leaking through the system from somewhere else? For instance, if parking brake release air is leaking past the seal into the service brake chamber, it would exhaust out of the treadle while the pedal is released.
Does it leak when pressed, released, or all the time?
With parking brakes applied or released?
More info makes for easier troubleshooting!
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need insite on diesel fuel treatment for todays fuel in yesterdays trucks
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