Coenut Posted January 9, 2016 Share Posted January 9, 2016 While driving a r model home the air pressure gauge started to climb right to 150 psi. For some time the truck was spitting at 120. Then it stopped and it would climb right to 150 psi. I changed the governor and it was fine for 10 miles or so. It now climbs right to 150psi. I was bob tailing and ran with the trailer valve open. There's a finned canister behind the cab. It has air in and air out along with some wires all cobbled together. Any info or ideas would be greatly appreciated. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/ Share on other sites More sharing options...
mrsmackpaul Posted January 10, 2016 Share Posted January 10, 2016 sounds like the governor is not working if you have changed that maybe its a crook air line or a blockage in a air line ????Paul Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319217 Share on other sites More sharing options...
Popular Post MHfred Posted January 10, 2016 Popular Post Share Posted January 10, 2016 Frozen air line? 3 Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319223 Share on other sites More sharing options...
turckster Posted January 10, 2016 Share Posted January 10, 2016 There are 3 ports on the air governor- exhaust, signal and unloader. The signal line is from the wet tank, its the air tank fed directly from the air dryer. When the pressure in the wet tank reaches 120 psi the air governor sends an air signal to the unloader port which goes to the air compressor head and dryer. If air continues to build to 150+ psi then either the signal line from the wet tank is plugged or the air governor is bad. On the older R models the signal/unloader lines were usually stratoflex line. It could be coming apart inside the line.To test the air governor install a test gauge inline or into one of the "Signal" ports on the air governor (gauge should go up to at least 150 psi). If the test air gauge is not showing the same value as your dash air gauges then the line is plugged from the wet tank. If the air psi is the same as the dash gauges move the test gauge inline or into a "unloader" port on the air governor. There should be no air psi on this line until at least 120 psi (depends where the air governor is set). Once that pressure has been reached then there should be air pressure (same as system psi). If this never happens then you have a bad air governor. Make sure there is no oil or water in the signal line, That can destroy an air governor in no time 1 Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319242 Share on other sites More sharing options...
Coenut Posted January 10, 2016 Author Share Posted January 10, 2016 I will check those lines. I suspect they are plugged or failing. Thank you very much. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319276 Share on other sites More sharing options...
Vladislav Posted January 12, 2016 Share Posted January 12, 2016 I have almost the same issue with one of my R688. The pressure goes up to 150 pci and than some protection valve opens in the air dryer (or somewhere below the chassis) and drops the pressure to 120 psi. I took the governor apart and than swapped it with the other off the second truck wich worked correct but had no good result. Haven't go on the fight path already yet, need to collect enough of info to start. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319652 Share on other sites More sharing options...
Timmyb Posted January 12, 2016 Share Posted January 12, 2016 Is the problem that it sits at 150 now instead of 120? Or does it continually build to 150 then drop to 120 and repeat every few minutes? Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319671 Share on other sites More sharing options...
Coenut Posted January 13, 2016 Author Share Posted January 13, 2016 It builds right to 150 psi and the relief valve opens but the compressor continues to build pressure. The pressure doesn't drop it stays high. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319749 Share on other sites More sharing options...
Mcrafty1 Posted January 13, 2016 Share Posted January 13, 2016 If it's below freezing ambient in your area I would find a quart of airline anti freeze and take the air intake line off that runs to the compressor and , with the engine running/compressor pumping slowly pour about half of a quart into the intake line, wait a minute and repeat with another half quart....this should open any frozen lines and let the system operate as designed. If this doesn't work, dig deeper, but for my money....I'd try this first. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319751 Share on other sites More sharing options...
Coenut Posted January 13, 2016 Author Share Posted January 13, 2016 When this was happening it was above 40f. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319753 Share on other sites More sharing options...
Mcrafty1 Posted January 13, 2016 Share Posted January 13, 2016 When this was happening it was above 40f. Chances are it wasn't frozen then, at the very least you should find an relief valve on one of your air tanks (mines on my wet tank) that won't let the system pressure build beyond a set point (Usually 20lbs. or so0 above the governor cut off) so you have multiple malfunctions.... Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319755 Share on other sites More sharing options...
Coenut Posted January 14, 2016 Author Share Posted January 14, 2016 There was a valve on the air dryer, almost like a turkey timer that would pop up and release some air but nothing from the went tank. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319865 Share on other sites More sharing options...
Timmyb Posted January 14, 2016 Share Posted January 14, 2016 My mate had a new governor that was set high at 1000kpa which is about 150psi. He pulled the black plastic cover off the bottom and set it lower. Seems funny that your old one done it too. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319942 Share on other sites More sharing options...
Coenut Posted January 14, 2016 Author Share Posted January 14, 2016 It worked fine for 10 miles then went back to building right to 150. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319988 Share on other sites More sharing options...
Back In Black Pulling Posted January 14, 2016 Share Posted January 14, 2016 Unloader valve in compressor might be stuck or blockage between Governor and valvesValves are usually behind air intake on side of compressor 1 Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-319989 Share on other sites More sharing options...
Trucking Ducking Posted March 18, 2022 Share Posted March 18, 2022 What was the solution Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492588 Share on other sites More sharing options...
Onyx610 Posted March 18, 2022 Share Posted March 18, 2022 6 years ago….what do you need help with? Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492631 Share on other sites More sharing options...
Joey Mack Posted March 18, 2022 Share Posted March 18, 2022 sounds like a govnah issue.... 6 year old post with a new question, I rekon.... jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492632 Share on other sites More sharing options...
Onyx610 Posted March 19, 2022 Share Posted March 19, 2022 40 minutes ago, Joey Mack said: sounds like a govnah issue.... 6 year old post with a new question, I rekon.... jojo More then likely Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492634 Share on other sites More sharing options...
mechohaulic Posted March 19, 2022 Share Posted March 19, 2022 kinda makes you wonder doesn't it. looking for the solution =WHY! do you have the same problem or just catching up on the 6 yr old topic. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492642 Share on other sites More sharing options...
Joey Mack Posted March 19, 2022 Share Posted March 19, 2022 my question is.... how do you find an old post? however I have typed it in to google and it will show a BMT listing... maybe thats how??? jojo Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492644 Share on other sites More sharing options...
Onyx610 Posted March 19, 2022 Share Posted March 19, 2022 3 minutes ago, Joey Mack said: my question is.... how do you find an old post? however I have typed it in to google and it will show a BMT listing... maybe thats how??? jojo Probably, and I’m gonna guess he never comes back. Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492645 Share on other sites More sharing options...
mechohaulic Posted March 19, 2022 Share Posted March 19, 2022 4 minutes ago, Joey Mack said: my question is.... how do you find an old post? however I have typed it in to google and it will show a BMT listing... maybe thats how??? jojo i find alot of old post by going to whos on line -then see what the guest are viewing. that turns up past history of topics. becomes a situation when finding yourself wanting to respond to old old topics Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492646 Share on other sites More sharing options...
Joey Mack Posted March 19, 2022 Share Posted March 19, 2022 I think a filter or a "Flag" on post's that are a year old and older would work,, no need to delete them just inform the viewer that they are older post's... jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492648 Share on other sites More sharing options...
Onyx610 Posted March 19, 2022 Share Posted March 19, 2022 3 minutes ago, Joey Mack said: I think a filter or a "Flag" on post's that are a year old and older would work,, no need to delete them just inform the viewer that they are older post's... jojo Right, just lock them out. I also think we need to start a thread with parts numbers/diagrams Quote Link to comment https://www.bigmacktrucks.com/topic/43446-air-pressure-runs-to-150/#findComment-492649 Share on other sites More sharing options...
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