123 Posted September 9, 2008 Share Posted September 9, 2008 Hi guys, I found this forum the other day, seems like a great place.I am working on the truck in my profile. I bought it this summer and am working on it when time allows. It's in decent shape, and it will not be in highway service anymore, just a yard truck.The air compressor seems to be putting out allot of oil. The first tank has oil coming out, a thick liquidy grease, gray in color. I'm guessing the pump needs rebuilding? How do I determine what model it is? I have a 350 mack motor. The pump is on the passenger side. Also, where is the governor? It seems to be working fine, it never really pumps over 120 psi. Should I be running a dryer/separator of some sorts? Do I need to flush the system with anything? How is that done?Thanks! Quote Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/ Share on other sites More sharing options...
Rob Posted September 9, 2008 Share Posted September 9, 2008 Hi guys, I found this forum the other day, seems like a great place.I am working on the truck in my profile. I bought it this summer and am working on it when time allows. It's in decent shape, and it will not be in highway service anymore, just a yard truck.The air compressor seems to be putting out allot of oil. The first tank has oil coming out, a thick liquidy grease, gray in color. I'm guessing the pump needs rebuilding? How do I determine what model it is? I have a 350 mack motor. The pump is on the passenger side. Also, where is the governor? It seems to be working fine, it never really pumps over 120 psi. Should I be running a dryer/separator of some sorts? Do I need to flush the system with anything? How is that done?Thanks!Hi Bolt, it sounds like you need to replace the compressor for sure. If the truck is not going to see road usage I would probably opt for a used one from a salvage yard to save dollars.I can't tell you if it right or not but the way I remove oil from compressed air lines is to run mineral spirits, or naptha through an engine washing gun with a small tip. After removing the wet tank, use the suction to blow compressed air through the line while at the same time sucking up the liquid from a can. Do this until the sludge or milky buildup is gone, then run fresh solvent again. These two solvent are mild enough that they will not attack the plastic parts like lines and such. Be sure to purge the system of the solven with water as hot as you can get it by the same method. The blow compressed air to dry the system. Flush the tank by removing the drain valve and pouring solvent into the tank. Put corks, or stoppers into the openings, and shake like hell for a bit, change solvent, then do it again! Sounds like fun at this point doesn't it? Reinstall all parts with replacement compressor, and charge the air up. Drain the system rapidly via the wet tank a couple of times, then when the discharge air is clear and dry, you should be ready to go. I would inspect all valves and rubber parts for decay and to ensure all works well before putting into usage.As far as a drier: In your projected usage I really don't think you will need it.Most likely the compressor you have is a Bendix Tu-Flo 500, or 501 as they were most common. Looking at the identification tag; It will either be red, or black silk screened. If it is black, the compressor has never been rebuilt. If it is red, at one time it has been gone through. All rebuilders that I have worked with follow this convention. If you elect to have yours rebuilt, REI Brake Service in Chicagoland does a good job reasonable for a hobby truck. I've used them a couple of times. Just be sure to let them know it is not a money maker. These compressors are easily picked up at any truck salvage yard also. Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-21901 Share on other sites More sharing options...
Freightrain Posted September 9, 2008 Share Posted September 9, 2008 My B was like that when I bought it. I finally bit the bullet and had it rebuilt(I think it was a TruFlo 500?). Mason Truck Parts in southern Ohio did the job. One day out, one day there, one day back and I was back in business. Wasn't cheap($500), but purrs like a kitten and uses NO oil. It came back painted black again, so wonder if they just duplicate what it was or should follow some "code"?It's taken a few years, but finally doesn't bleed oil down the dash!Welcome to the site. Hope you find it as useful/friendly as the rest of us. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-21904 Share on other sites More sharing options...
bulldoggin' Posted September 9, 2008 Share Posted September 9, 2008 Rob is right in need of a compressor bad. Quote KEEP THE BLACK SMOKE ROLLIN Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-21915 Share on other sites More sharing options...
David Posted September 10, 2008 Share Posted September 10, 2008 When you have the compressor off check the colant lines. I've seen them get old, rusty, and plugged. No cooling will cause a new compressor to go bad in a hurry. Quote Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-21916 Share on other sites More sharing options...
Freightrain Posted September 10, 2008 Share Posted September 10, 2008 Ya, I put all new lines on mine before re-installing it. Quote Larry 1959 B61 Liv'n Large...................... Charter member of the "MACK PACK" Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-21922 Share on other sites More sharing options...
123 Posted September 12, 2008 Author Share Posted September 12, 2008 Thanks for the input. I get about 1/4 cup of oilly stuff out of the first tank daily now. I guess I did get some of the accumulation cleared out. I can't find a number on the pump, I will try calling Mack and seeing if they can give me an ID based on the remaned engine's serial number. The pump and the block seemed to be painted at the same time. Quote Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-21936 Share on other sites More sharing options...
Gambi80 Posted September 13, 2008 Share Posted September 13, 2008 Just as another option since this won't be a road truck for you, try E-Bay for a compressor. My dad just picked up a reman for $150...versus the $500+ you'd pay for a rebuild or a new/reman one from a dealer. It's not a bad job to replace it. A few weeks ago, the accessory drive gear quit on my '97 CH. Replacing that involved dropping the oil pan, removing the power steering pump and also the air compressor. The compressor is pretty damn heavy, a two man job due to the ackwardness of the location, but it's do-able. Quote Ever wonder how a blind person knows when to stop wiping? Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-21981 Share on other sites More sharing options...
scooter Posted September 18, 2008 Share Posted September 18, 2008 Connect the Intake for the compressor to the boost side of the turbo and it will stop 90% of the oil. Mine was hooked up to the air filter side and used to get a lot of oil in the tanks, Air dryers are a must!! I drain my tanks every 2 months and get almost nothing Quote Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-22087 Share on other sites More sharing options...
Rob Posted September 18, 2008 Share Posted September 18, 2008 Connect the Intake for the compressor to the boost side of the turbo and it will stop 90% of the oil. Mine was hooked up to the air filter side and used to get a lot of oil in the tanks, Air dryers are a must!! I drain my tanks every 2 months and get almost nothingI don't think I've ever seen the intake piping to an air compressor plumbed into the suction side, (low pressure) of a turbocharger. Seems the flow of air would be fighting itself in operation for the compressor.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-22089 Share on other sites More sharing options...
terry Posted September 19, 2008 Share Posted September 19, 2008 Every older mack i have worked on had it hooked to the suction side. terry Quote Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-22106 Share on other sites More sharing options...
David Posted September 19, 2008 Share Posted September 19, 2008 Mack issued a service bulletin about this change many years ago. You can run a hose around the back side of the block and remove a plug from the intake manifold. So your getting air after it's passed through the aftercooler. Plug the hole on the ductwork so it doesn't suck in unfiltered air. You can also buy filter kit that bolts onto the compressor with replaceable filters. Quote Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-22108 Share on other sites More sharing options...
123 Posted September 19, 2008 Author Share Posted September 19, 2008 Mines plumbed to the intake side of the turbo. What would be better, running it to the boost side, or running it of a separate air intake filter?Does anybody have a link of the service bulletin where it was plumbed to the intake manifold? Quote Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-22127 Share on other sites More sharing options...
Gambi80 Posted October 2, 2008 Share Posted October 2, 2008 I don't think I've ever seen the intake piping to an air compressor plumbed into the suction side, (low pressure) of a turbocharger. Seems the flow of air would be fighting itself in operation for the compressor.RobFunny how you mention that...The handful of trucks I've been around all had the intake to the compressor plumbed into the suction side of the turbo...until I bought my CH. I thought it was a bit weird, but now I understand. The hose running from the intake manifold to the compressor developed a nice size hole and produced a loss of 5-8 lbs of boost until I discovered and fixed it. Weird how a small cigar sized hole could lose that much air. Some spare hose and a couple clamps and it's good as new. Quote Ever wonder how a blind person knows when to stop wiping? Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-22450 Share on other sites More sharing options...
Packer Posted October 2, 2008 Share Posted October 2, 2008 I do a little 4 wheeling in a much more than stock Jeep.My air compressor for the air lockers draw air from the air filter piping.Two reasons:Filtered air for the compressorand only one filter to change.Dry filters work great; oil bath may be another issue.But it works great on my B-61.Packer Quote Keep a clutchin' Link to comment https://www.bigmacktrucks.com/topic/4192-air-system-tune-up/#findComment-22455 Share on other sites More sharing options...
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