Onyx610 Posted December 6, 2022 Share Posted December 6, 2022 1 hour ago, Freightrain said: Yes. Ties into the water pump and returnd to the side of the block. Typically no air drier on these trucks from factory. Ahhh ok, yea typically when air dryer cartridges/filters get plugged truck won’t build air. With the head gasket on the compressor that would show up in the cooling system. I’ll step back and watch now. Looks like you and hayseed got this. Quote Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517512 Share on other sites More sharing options...
Freightrain Posted December 6, 2022 Share Posted December 6, 2022 Need to confirm it is a 500 pump. Then make sure it doesn't have a drier hung on it? About the size of a coffee can with line coming from compressor and going back to tank. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517530 Share on other sites More sharing options...
CalebB Posted December 6, 2022 Author Share Posted December 6, 2022 39 minutes ago, Freightrain said: Need to confirm it is a 500 pump. Then make sure it doesn't have a drier hung on it? About the size of a coffee can with line coming from compressor and going back to tank. Yes it is a 500 pump. It does not have an air dryer. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517535 Share on other sites More sharing options...
CalebB Posted December 6, 2022 Author Share Posted December 6, 2022 10 hours ago, Hayseed said: Welcome, Caleb. I'm Sure We'll get your Truck issues sorted.. After sitting for that length of Time the entire Air/Brake system will need a good dose of TLC, to ensure It's safe to use.. I'd see if you can use some "Shop Air" to pump up the Tank & Test if the Brakes ect are working as they Should. I'd also ensure that the Brass/Steel line directly out of the Compressor isn't Carboned up. The unloader valve sticking has already being Mentioned.. Just methodically go through all the Basics before spending money on a another Air compressor. would be My advice...Tax free Today..lol I hadn’t thought of pumping up the tank with shop air. I’ll try that when I get off work! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517536 Share on other sites More sharing options...
doubleclutchinweasel Posted December 6, 2022 Share Posted December 6, 2022 Try this on for size... bendix-tu-flo-400-500-1000-air-compressor-user-manual.pdf 1 Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517541 Share on other sites More sharing options...
CalebB Posted December 7, 2022 Author Share Posted December 7, 2022 Well I got all the air lines cleaned out and it makes 120 psi, but I’ve got a new problem. When pressing down on the brake pedal, there is air shooting out of what looks to be an exhaust for the air brakes. There are two of them but only one is spewing air. I can provide a picture if needed. Quote Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517681 Share on other sites More sharing options...
D-Day Posted December 7, 2022 Share Posted December 7, 2022 It may be a quick release valve I hate it when I find a quick release valve that someone put in to split the brake line down to the service brakes they can stick open while driving and then you have no brakes there should just be a T there, quick release valves are more suitable for the parking brake if equipped with the bigger double brake chambers Quote Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517688 Share on other sites More sharing options...
CalebB Posted December 7, 2022 Author Share Posted December 7, 2022 5 minutes ago, D-Day said: It may be a quick release valve I hate it when I find a quick release valve that someone put in to split the brake line down to the service brakes they can stick open while driving and then you have no brakes there should just be a T there, quick release valves are more suitable for the parking brake if equipped with the bigger double brake chambers Ok so what do I need to do to fix it? Quote Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517690 Share on other sites More sharing options...
Hayseed Posted December 7, 2022 Share Posted December 7, 2022 2 hours ago, CalebB said: I can provide a picture if needed. Please. It will save a Lot of second guessing..! 1 Quote "Be who you are and say what you feel...Because those that matter...don't mind...And those that mind....don't matter." - Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517691 Share on other sites More sharing options...
D-Day Posted December 7, 2022 Share Posted December 7, 2022 A picture would be good to make sure that it is not a brake relay valve of some type old trucks have a lot of unusual modifications over they're life span Quote Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517694 Share on other sites More sharing options...
Freightrain Posted December 7, 2022 Share Posted December 7, 2022 Quick release is a small box with a 1" hole in the bottom that releases air pressure when you let off the brakes to "quickly" release the brakes. They are mounted right at the axle with the two air lines going to the cans (There two, one for service, one for parking brakes). They do fail, and like you mention, it will leak air on application instead of release. The front axle brakes will have a similar item. It is what gives that air Woosh sound when you release the brakes. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517699 Share on other sites More sharing options...
doubleclutchinweasel Posted December 8, 2022 Share Posted December 8, 2022 (edited) Quick Release Valves... Edited December 8, 2022 by doubleclutchinweasel 1 Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517736 Share on other sites More sharing options...
doubleclutchinweasel Posted December 9, 2022 Share Posted December 9, 2022 On 12/7/2022 at 5:13 PM, CalebB said: Ok so what do I need to do to fix it? Any news? Anything? Anything? Quote "Eagles may soar, but weasels don't get sucked into jet engines." Link to comment https://www.bigmacktrucks.com/topic/70825-b61-low-air-pressure/page/2/#findComment-517816 Share on other sites More sharing options...
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