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Dave Shepard

2674 not making air.

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Parked the truck last week, was working fine. Now it won't make any air pressure. Changed governor, no effect. Compressor gets up to water temp of engine, so I don't think it's got any ice in it. Any suggestions appreciated. Thanks. It's on an NTC350.

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1 hour ago, Dave Shepard said:

Parked the truck last week, was working fine. Now it won't make any air pressure. Changed governor, no effect. Compressor gets up to water temp of engine, so I don't think it's got any ice in it. Any suggestions appreciated. Thanks. It's on an NTC350.

What compressor; Bendix, Midland, or Cummins? Sounds as if you have a valve/unloader hanging open and if the governor is ruled out, remove it from the compressor, (if direct mounted) and ensure the compressor is/is not pushing air out of it's head by disconnecting the discharge line while the engine runs. All compressor heads are easy to service or repair with a kit. To cease making air without degradation of air output sounds like a Cummins compressor as they are single cylinder. 

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If it’s a true flow compressor take the inlet manifold off (either behind little air filter or hooked to a hose to big air cleaner) couple little valves in there that like to rust and stick open. Usually can free them up with penetrating oil and a little tapping. 

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Thank you for the replies. I'm not sure who made the compressor,  but it does have the inlet hose that comes down from the engine air intake. It goes into the left side of the comp head, and there is a little line from an alcohol tank that goes in there, too. After thinking about it all afternoon, I've decided there must be some sort of valve on the intake side that is not closing, as there is no air coming out anywhere when I take the lines off. 65806, your comment confirms my suspicions. As the truck has been working up until this week, im hoping a little lube will do the trick. Again, thanks. 

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There does appear to be an issue with stuck valves. I need to pull the head, but didn't have any plugs for the coolant lines. You can see the tops of the valve stems in the one picture. The left one is stuck. The valve stems are in the top of the head just in front of the outlet air fitting. It's a two cylinder compressor. I don't know the make,  it has a Like-Nu tag on it, so it's a rebuild.

20190104_165126.jpg

20190104_165122.jpg

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Can you spray them with lube and wiggle them loose without removing the head?  I’ve been able too most times but not every time 

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I don't think so. The left one is stuck down, and I can't get it to come back up. I suspect that one's been down for some time, as the truck doesn't make air very fast. I think the other one has just gotten sticky recently, maybe because of the cold. I've recently become the person keeping an eye on this equipment. I'm going to get this back into proper working order while it's apart. I may not be able to fix all the broken stuff, but I'm going to tackle every problem that comes along. I'll know more tomorrow. Thanks. 

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It’s a bendix tu-flo 501 I think.  There is a kit from bendix with both the valves springs and the gasket.  

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Keep in mind I know absolutely nothing about the Midland 1300, or 1600 series air compressor on your truck but here's a link for parts you'll want to replace: https://www.amazon.com/Midland-El13111-El16111-Compressors-Interchange/dp/B00V5APV3K

Drain the coolant down in the truck and remove the compressor head. Clamp the head to a bench, warm the socket headed screw in plugs, (softening the loctite compound) retaining the exhaust valve disc(s) with a propane torch and screw them out using an  Allen wrench. Discard the sealing plates. The intake check valve housings have three eliptical slots and you will need to fashion a wrench to remove them but they unscrew also after warming to soften the loctite compound retaining them. DO NOT beat on these as if you deform their seats, they are scrap. Discard the sealing discs there also. Remove the unloader pins/pistons from the head with a pair of needle nose pliers or needle nose vice grips if stuck good. They are under the top plate already removed in your prior photo. Clean everything up good and reassemble using blue loctite to lock the sealing disc seats into the head casting. Use the barium grease in the kit and nothing else to lubricate sliding parts. 

The kit in the link has everything you need to service the head correctly. It will take a novice about an hour to rebuild it and then reinstall. Those stems suffer from corrosion and if you clean them up you'll have the pleasure of the doing the job a time or two again on pretty short order.

Just for chits and grins, here is a Midland compressor head on my bench showing the sealing valves:

image.jpeg.a54abab97ab8c6d332625d553df8d9e2.jpeg

"Like-Nu" is Haldex's remanufactured naming convention.

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Thanks. I'll look into getting the kit before I pull the head off. 

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6 hours ago, Dave Shepard said:

Thanks. I'll look into getting the kit before I pull the head off. 

Also acquire a couple sheets of 220 grit silicone carbide, (wet or dry) sandpaper and a smooth steel bench top. Tape the sandpaper securely to the bench top with abrasive side up. Oil it up a bit with hydraulic oil or something thin and scrub the bottom of the head while the valves are out. Polish it good till the scratch pattern is smooth and even by moving the head casting in a figure 8 pattern across the sandpaper. I then either place the cylinder head and small parts into the kitchen dishwasher running in the overnight hours and get up REALLY early, (to not get caught) so any "grit" is washed clean of the casting, or run it through my parts washer if I have more to load with it:

image.jpeg.5668c4ff1873abdf212c1214a0ac2643.jpeg

It's not a bad idea to polish up the sealing disc seats also with 400 grit wet or dry using the same technique. Bore brushes run through the unloader stem bores should also be done to remove any foreign material accumulated over the years.

You seem to want to do this correctly and it's the way I've done a few over the years. Don't matter the brand, they're pretty much the same with the valves needing attention every now and then. Always a pretty good idea to run some alcohol mist through the intake port to remove any sludge accumulation in the bores, or unloader working areas.

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Got the parts today, and no barium grease. Not sure where to get that. Head is off, I'll work on getting everything apart and cleaned. 

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Update. One piston goes up and down, the other just stays up. Now pricing rebuilt compressors.

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On 1/14/2019 at 2:31 PM, Dave Shepard said:

Update. One piston goes up and down, the other just stays up. Now pricing rebuilt compressors.

Without your original numbers:

13CFM part# KN 13040X  $281.55 cost with no core charge shown

16CFM part# KN16040X   $368.89 cost with $182.50 core charge AND 14 day lead time

Those compressors use aluminum rods and usually the rod cap comes loose from lack of Loctite on the retention fasteners during the rebuild process. Although rare to occur with a "Like-Nu" branded rebuild, it can happen. The compressors are presure lubricated by the engine oil supply so they are not starved for oil.

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It's an EL13040X pump. Where are you getting that price? NAPA wants $350 plus shipping from MO. IH wanted $550.

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Just now, Dave Shepard said:

It's an EL13040X pump. Where are you getting that price? NAPA wants $350 plus shipping from MO.

Buddy of mine owns a parts store and usually treats me right. You have a very common compressor.

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Thanks. I'm surprised nobody has one in stock. 

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35 minutes ago, Dave Shepard said:

Thanks. I'm surprised nobody has one in stock. 

Try your somewhat local "Fleetpride" store. I seldom use them but they are plentiful around the country. I prefer the independent "small guy" still trying to make a living.

You can get parts and rebuild that compressor for a couple hundred. You could also send it to REI in Chicagoland for a reasonable rebuild: https://www.rebuildersenterprises.com/  I've had them rebuild several over the years.

Here is an ebay link if you'd like to go that way:   https://www.ebay.com/itm/HALDEX-EL13040X-COMPRESR-COMPRESS/302901625115?hash=item468658011b:g:TEYAAOSwESZbNPNy:rk:4:pf:1&frcectupt=true

I quite using Napa stores back in the 70's when internal corporate politics started mandating the way the independents conducted business.

 

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I am replacing the compressor on the 250 Cummins in my 1964 Emeryville. Problem was like yours, building up pressure slowly then not making pressure.Compressor is a Bendix-Westinghouse Tu-Flo 500. $330 plus core at Napa. problem with my truck is it sits so much.

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On 1/14/2019 at 2:31 PM, Dave Shepard said:

Update. One piston goes up and down, the other just stays up. Now pricing rebuilt compressors.

That happens more than you think. If your valves wouldn’t have stuck you would have lost air when the other rod broke off. That other piston has probably been not moving for a while

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So, what's the trick to getting this thing unbolted from the engine? I can't even feel the bolt on the backside of the compressor, and I can put a wrench on the back bolt of the PT pump, but I can't turn it. I have a reman pump. Thanks for any input. 

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1 hour ago, Dave Shepard said:

So, what's the trick to getting this thing unbolted from the engine? I can't even feel the bolt on the backside of the compressor, and I can put a wrench on the back bolt of the PT pump, but I can't turn it. I have a reman pump. Thanks for any input. 

Special bent wrench’s and it isn’t fun. Goggle snapon or someone’s compressor or obstruction wrench. 5/8 and 3/4 I think.

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But how do you get the bolt back in if you can't see it or touch it? Can it be done with the oil pump and power steering pump in place?

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8 hours ago, Dave Shepard said:

But how do you get the bolt back in if you can't see it or touch it? Can it be done with the oil pump and power steering pump in place?

Yes here are pictures of wrenches you need . Stick your head in and you can feel around to get at bolts. It is painful process.

D39166E3-551C-41B8-AEDA-2404B18C207C.png

52573718-6C3E-415A-955E-9CBB25321C33.png

B3B9A783-28DF-4EE1-82C0-EAE40C097D87.png

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I already had the 9/16 X 5/8 wrench. yes it took a while to get that one bolt out.had to feel for the bolt head with one finger and use left hand to work wrench. real slow process. is going to take a while to put back on.. then the injector pump bolts to back of compressor and it has a hard to get to bolt also. good thing I am not in a hurry for truck.

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