'71 M35A2 air compressor lubrication

[rustystud]

Could a screen be added to the compressor mounting bracket to catch the debris in case of a failure? I haven’t seen the inside of a bracket in a long time.

Actually back in the 1970's, a lot of commercial trucks had a gasket on the bottom of the compressor that had a built in "mesh" to catch any debris if the compressor failed. I haven't seen any since then, though I'm sure you could make one up.

 

[texas30cal]

Sounds like a good project for the weekend if I can find some fine mesh screen, found #20 mesh stainless but have to order that in. Thanks for the idea!!!

 

[rustystud]

Sounds like a good project for the weekend if I can find some fine mesh screen, found #20 mesh stainless but have to order that in. Thanks for the idea!!!

Glad to help. Hope it works out OK.

 

[TAZZJR]

It never actually stopped working it just started to make some horrible squealing/scraping noises. I will definitely change fluids and filters to be on the safe side. Are you saying the oil pan needs to be dropped or just fluids changed?

I am wondering if the noise ever returned. My truck is having a similar problem and I'm trying to decide what to do. I might disconnect the lubrication supply line and check for a plug in my line and go from there.

 

[chadtrees]

I am wondering if the noise ever returned. My truck is having a similar problem and I'm trying to decide what to do. I might disconnect the lubrication supply line and check for a plug in my line and go from there.

I ended up replacing the compressor and all is well now.

 

[nchittendon]

It's funny I stumble across this thread.

Went out to start my truck the other day in preparation for the snow we had inbound. I'm doing my walk around, get back to the cab, and notice the air buzzer still going loud and proud. That's never happened. The gauge is still reading zero. I climb down, and pull the air tank cords. Nothing.

This is the first time she's done this to me. No weird noises, no warning.

We currently are not talking to each other. I'm sure at this point she knows i'm upset with her. Had to drive the wife's subaru in the snow storm instead.

 

[cattlerepairman]

Nchittendon, she may just have a frozen governor from a bit of humidity in the line. Running the engine until the compartment warms up would do the trick.
You did not mention any weird noises, so the compressor is most likely just running unloaded.

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[davidb56]

Nchittendon, she may just have a frozen governor from a bit of humidity in the line. Running the engine until the compartment warms up would do the trick.
You did not mention any weird noises, so the compressor is most likely just running unloaded.

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that happened to me last month in cold weather too. thats why I replaced it, but I kept the old one for back up, because I figured it just froze.

 

[nchittendon]

No weird noises that I could tell anyway. So I'm hoping it's just frozen.

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[TAZZJR]

I'm currently trying to replace my air compressor. I cant get a tool on the front two nuts mounting the air compressor down. It's the single piston compressor. Does anyone have advice?

 

[tommys2patrick]

TAZZJR--I did a head job and replaced all the gaskets. several accessory mounts, the air compressor included, presented some challenges. If you are referring to two of the four large nuts on the compressor mount studs holding it to the mounting flange on the block, you have two options. One--remove the mounting flange from the block and leave the compressor attached for now. open end wrenches work best on the upper mount cap screws to the block, while a woble end 6" plus extension on your ratchet works best on the rest. 1/4" extension or 3/8" as its a tight squeeze. I think there are 7 or 8 of them. one is tucked up in there pretty far to the bottom front. looking at the manual for the removal instructions you can see the location better. two-- removing the four stud nuts on the compressor . an open end wrench works well but tedious as you can only swing it a very short stroke. the worst is the one that also has the tach drive cable attached to a short arm from the stud. its is relatively soft metal and can be slightly bent down to get a short/stubby open end wrench on it. I don't have any stubby box wrenches but that could work if such a thing exists. the bottom of the compressor itself is aluminum. it soft and the lock washers dig in pretty good. its a casting so its relatively fragile. no a lot of torque is required in mounting it or taking it off. I actually took the fender off to make my overall project a bit easier. I had to pull the injectors so removing the fuel lines gave more access as well. hope my two cents helps.

 

[TAZZJR]

TAZZJR--I did a head job and replaced all the gaskets. several accessory mounts, the air compressor included, presented some challenges. If you are referring to two of the four large nuts on the compressor mount studs holding it to the mounting flange on the block, you have two options. One--remove the mounting flange from the block and leave the compressor attached for now. open end wrenches work best on the upper mount cap screws to the block, while a woble end 6" plus extension on your ratchet works best on the rest. 1/4" extension or 3/8" as its a tight squeeze. I think there are 7 or 8 of them. one is tucked up in there pretty far to the bottom front. looking at the manual for the removal instructions you can see the location better. two-- removing the four stud nuts on the compressor . an open end wrench works well but tedious as you can only swing it a very short stroke. the worst is the one that also has the tach drive cable attached to a short arm from the stud. its is relatively soft metal and can be slightly bent down to get a short/stubby open end wrench on it. I don't have any stubby box wrenches but that could work if such a thing exists. the bottom of the compressor itself is aluminum. it soft and the lock washers dig in pretty good. its a casting so its relatively fragile. no a lot of torque is required in mounting it or taking it off. I actually took the fender off to make my overall project a bit easier. I had to pull the injectors so removing the fuel lines gave more access as well. hope my two cents helps.

Awesome. I was thinking about it last night . I might have to go to harbor freight and buy a 11/16 wrench to cut it in half. I'll keep trying next chance I get.

 

[TAZZJR]

Well I do believe we fixed my air compressor and cured the temperamental rattle..

I ended up getting a set of short wrenches. I was able to work 11/16 around the compressor pully to turn the nut holding the compressor on. at times the wrench was at a 45 on the nut. Very awkward but manageable when climbing all over the motor. The wobble socket was never able to fit on the front two nuts.

After getting the compressor out and on a bench I was able to see inside the compressor and found no damage to the cylinder. The only thing that was found was an absence of an abundance of oil residue. With no belts attached and everything pulled away from the drive pully we decided to see if we could make the M35A2 produce oil. DO NOT DO THIS IN A CLOSED SPACE, NEAR ANTHING THAT CAN PRODUCE A SPARK OR FLAME, NEAR ANYTHING YOU CARE ABOUT, OR LIVING THINGS. My 70 y.o., disabled, father and my wife looked at the motor as I turned on the truck. For a while nothing happened. I jumped out of the truck and decided to take a look. As I leaned in to take a look under the hood, a 15' geyser of oil shot in to the air. With much screaming and laughter we were all able to get out of the way and I was able to reach the shut of for the motor.

I believe there was a clog in my oil supply to my air compressor. I was able to attach the belt and run the motor for a while with out producing the rattle. I ran out of time today to finish putting the truck back together. I will need more run time to see if it is fixed or if I need to find a check valve that has failed. The only casualty of today is the copper crush ring under the 1 & 1/4 nut on the top of the motor. That easier on the wallet than the price of a new compressor.