Uamakua
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- Location
- Denver, Colorado
I have a 1985 M931A1, Cummins diesel and all of the usual attachements. The problem is the purge function of the air system stopped working recently. Now it will climb past 120 pounds where it usually purges and up to 130 where I shut the engine down and manually bleed the air out of the system.
My system builds air very well this is not a probelm. It sort of did this off and on for a short while then has stopped purging pressure for good now.
This system has the Haldex air dryer and this has been gone through. I put on a new Bendix governor. I have disconneted the line from the governor to the air dryer control port and pressurized the system, and at the supposed pressure cut off there is no air coming out of the line from the governor, so no signal getting to the purge valve on the air dryer to dump excess air.
Another oddity with this situation is that the air horn or the air wipers do not work, and I am aware the air line to the air horns also feeds the governor or so it appears, probably same pressure feed to my wiper motors. All of this worked fine before this situation came up so I am assuming they interconnected somehow.
The only air leak I see in the entire system is from the pressure relief valve at the front of the rear tank on the passenger side of the truck. It leaks all the time no matter the pressure so not sure if it got overpressured and now has this leak or if it is even working now.
If the air signal can get to the purge valve on the air dryer I am confident it would work, but why no air signal and no air to the horns and such that are in line with the governor?
Any help would be great I am baffled at this point! Thank you.
My system builds air very well this is not a probelm. It sort of did this off and on for a short while then has stopped purging pressure for good now.
This system has the Haldex air dryer and this has been gone through. I put on a new Bendix governor. I have disconneted the line from the governor to the air dryer control port and pressurized the system, and at the supposed pressure cut off there is no air coming out of the line from the governor, so no signal getting to the purge valve on the air dryer to dump excess air.
Another oddity with this situation is that the air horn or the air wipers do not work, and I am aware the air line to the air horns also feeds the governor or so it appears, probably same pressure feed to my wiper motors. All of this worked fine before this situation came up so I am assuming they interconnected somehow.
The only air leak I see in the entire system is from the pressure relief valve at the front of the rear tank on the passenger side of the truck. It leaks all the time no matter the pressure so not sure if it got overpressured and now has this leak or if it is even working now.
If the air signal can get to the purge valve on the air dryer I am confident it would work, but why no air signal and no air to the horns and such that are in line with the governor?
Any help would be great I am baffled at this point! Thank you.