PEIFamily Posted January 20, 2017 Report Share Posted January 20, 2017 Trying to track down an air loss. The truck will cycle the compressor every 15 minutes just sitting idling and will drop you about 60psi overnight and if left 2 days, it's down to 20psi. Been all over the truck with soapy water, even tried shaving cream at a few things like the passthru. I do have a whisper and went over everything multiple times but couldn't find anything wrong. Bags are all good, no fittings seem to be leaking no noise of air leaks inside dash, etc.. Suggestions on what to do now? It has a new rear leveling valve and governor installed but this has been ongoing. Thanks Jason Link to comment Share on other sites More sharing options...
GlennWest Posted January 20, 2017 Report Share Posted January 20, 2017 That is better than mine. Link to comment Share on other sites More sharing options...
sclord2002 Posted January 20, 2017 Report Share Posted January 20, 2017 Better than mine, also. If I could get my air leaks to that point, I would be happy.......but that is just me. Charlie Link to comment Share on other sites More sharing options...
Nigel Posted January 20, 2017 Report Share Posted January 20, 2017 Did you check the air tanks? They are prone to rusting in between where they almost touch each other especially on our trucks that have seen salt. Also agree with the others your leak down is quite acceptable. When I bought mine it would hold above 60psi for a week but I knew that was unusual for a commercial truck. Nigel Link to comment Share on other sites More sharing options...
SIBERNUT Posted January 20, 2017 Report Share Posted January 20, 2017 Check the air line & fittings going to the fan clutch, that was one of mine Link to comment Share on other sites More sharing options...
bigstick Posted January 20, 2017 Report Share Posted January 20, 2017 If I went to our shop foreman with that "problem" he would laugh at me and tell me to come back when there is a real issue Link to comment Share on other sites More sharing options...
SuiteSuccess Posted January 20, 2017 Report Share Posted January 20, 2017 Jason, Air leaks are the bane of our existence. I have one on my front drivers frame rail that I just cannot locate. It is audible just with an ear from three feet. Have used the whisper and soapy water. The whisper even at the lowest setting gives a constant tone in the general area so I can't hone in on it. Also Sibernut is correct. I just had my fan clutch replaced due to a big leak around the front seal. Link to comment Share on other sites More sharing options...
Shallow Draft Posted January 20, 2017 Report Share Posted January 20, 2017 Jason, Air leaks are the bane of our existence. I have one on my front drivers frame rail that I just cannot locate. It is audible just with an ear from three feet. Have used the whisper and soapy water. The whisper even at the lowest setting gives a constant tone in the general area so I can't hone in on it. Also Sibernut is correct. I just had my fan clutch replaced due to a big leak around the front seal. There is T connector here that mine was leaking from. This leads to the valve that operates the exhaust brake. I replaced the T and the valve and solved a big hard to find leak. Link to comment Share on other sites More sharing options...
SuiteSuccess Posted January 20, 2017 Report Share Posted January 20, 2017 There is T connector here that mine was leaking from. This leads to the valve that operates the exhaust brake. I replaced the T and the valve and solved a big hard to find leak. Yes, I had a leak there also and replaced that T and line to the valve. Solved that one but the one left is further to the front and in a wire/airline bundle that I'm going to have to get to and remove about 20 cable ties. Being old and arthritic., just not easy to scoot up under the front of the truck and get to that bundle. Link to comment Share on other sites More sharing options...
Ronbo Posted January 20, 2017 Report Share Posted January 20, 2017 Most of us would love to have your problem. I still have 6 air bags to replace before I even start trying to find air leaks. But at $200 each and not feeling like doing the work, it will take time. Link to comment Share on other sites More sharing options...
SIBERNUT Posted January 20, 2017 Report Share Posted January 20, 2017 DOT max air leak engine off semi & trailer combo 4 lbs in one minute. 3 lbs straight truck or bobtail. Link to comment Share on other sites More sharing options...
rickeieio Posted January 20, 2017 Report Share Posted January 20, 2017 DOT max air leak engine off semi & trailer combo 4 lbs in one minute. 3 lbs straight truck or bobtail. That doesn't seem like much until you consider from full air (~120 psi) to having the maxi (spring brakes, for you younger folks) set is only 15 minutes. Most of the leaks I'm repairing are by replacing the o-ring in the fitting. No trimming of lines or other manipulations. In fact, when I find a leak, I nearly always replace the o-ring anyway. Link to comment Share on other sites More sharing options...
Darryl&Rita Posted January 20, 2017 Report Share Posted January 20, 2017 Most of us would love to have your problem. I still have 6 air bags to replace before I even start trying to find air leaks. But at $200 each and feeling like doing the work, it will take time. How are you paying that much? Cab bags are way under that, even dealer price, and suspension bags were less that $200 per. Link to comment Share on other sites More sharing options...
Alie&Jim's Carrilite Posted January 20, 2017 Report Share Posted January 20, 2017 Dig behind the dash. I had several small air leaks on the dash valves, johnson bar, and dash gauges. My air ride seats also leak. The driver's side bad enough that I put a valve on it to turn the air off to the seat. Link to comment Share on other sites More sharing options...
Ronbo Posted January 21, 2017 Report Share Posted January 21, 2017 Darryl it is a kenworth with 8 suspension air bags. I have already replaced 2. I have also replaced the cab air bags. Link to comment Share on other sites More sharing options...
Darryl&Rita Posted January 21, 2017 Report Share Posted January 21, 2017 That makes more sense. I knew you were either 4 or 8 bag suspension, but couldn't remember if you were singled or tandem. I dug out the truck receipt book, and paid $138 per bag, at the local GreatWest Kenworth. Firestone manufactured. Link to comment Share on other sites More sharing options...
PEIFamily Posted January 21, 2017 Author Report Share Posted January 21, 2017 Thanks everyone. I was worried it was still excessive. The fan clutch was replaced just before I got the truck. One place I never checked yet that was mentioned, my air seats. I have 5 air swats in it and I will pull back the carpet to listen. The carpet or underlay likely would muffle it if there was a leak there at any fittings. Thanks Link to comment Share on other sites More sharing options...
Alie&Jim's Carrilite Posted January 21, 2017 Report Share Posted January 21, 2017 Thanks everyone. I was worried it was still excessive. The fan clutch was replaced just before I got the truck. One place I never checked yet that was mentioned, my air seats. I have 5 air swats in it and I will pull back the carpet to listen. The carpet or underlay likely would muffle it if there was a leak there at any fittings. Thanks When you finish finding your leaks, come find mine. I still have 1 mysterious leak that I cannot track down. It all depends on how the truck sits, with no rhyme or reason. Flat parking lot, 3 hours 30lbs down, on an unlevel gravel campsite, hold air for days. Then the opposite will occur, park somewhere slightly unlevel and it leaks down, but fine in Walmart for 2 hours. HeWhoKnowsLittle- Roger, suggested this as well, with your brakes off, knobs pushed in, wheels chocked, check your brake circuits. Might find a leak on an active line, brake can, fitting, etc. Link to comment Share on other sites More sharing options...
billr Posted January 21, 2017 Report Share Posted January 21, 2017 Check the firewall pass through connectors. They are notorious on Volvos. Fairly easy to replace. I've done almost all of ours. The orings in them are not standard. Almost impossible to find. So end up buying the connectors from Volvo. Link to comment Share on other sites More sharing options...
Ronbo Posted January 21, 2017 Report Share Posted January 21, 2017 Is that the Greatwest Kenworth in Canada? Link to comment Share on other sites More sharing options...
Alie&Jim's Carrilite Posted January 21, 2017 Report Share Posted January 21, 2017 Check the firewall pass through connectors. They are notorious on Volvos. Fairly easy to replace. I've done almost all of ours. The orings in them are not standard. Almost impossible to find. So end up buying the connectors from Volvo. Already replaced it. No leaks inside or out. It's a mystery leak... Link to comment Share on other sites More sharing options...
Darryl&Rita Posted January 21, 2017 Report Share Posted January 21, 2017 Is that the Greatwest Kenworth in Canada? Yup. Used the Grande Prairie branch. Link to comment Share on other sites More sharing options...
StubbleJumper Posted January 21, 2017 Report Share Posted January 21, 2017 When you finish finding your leaks, come find mine. I still have 1 mysterious leak that I cannot track down. It all depends on how the truck sits, with no rhyme or reason. Flat parking lot, 3 hours 30lbs down, on an unlevel gravel campsite, hold air for days. Then the opposite will occur, park somewhere slightly unlevel and it leaks down, but fine in Walmart for 2 hours. HeWhoKnowsLittle- Roger, suggested this as well, with your brakes off, knobs pushed in, wheels chocked, check your brake circuits. Might find a leak on an active line, brake can, fitting, etc. Sounds like a leveling valve. Sometimes if they aren't adjusted just right they will exhaust out. Link to comment Share on other sites More sharing options...
kkesp Posted February 7, 2017 Report Share Posted February 7, 2017 Mine turned out to be turbo control valve. When it starts leaking it vents out the exhaust so can't be heard and didn't show up with the soapy water. They also can't be rebuilt and are in the $800-$900 range. I finally gave up looking and took it to the volvo repair. Link to comment Share on other sites More sharing options...
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