Junk Air-Packs

[militarysteel]

how many of you had issues with your air pac locking up on ya? we just when through 3 air packs, and the 3rd is not as bad, -- I'm thinking a lot of people have issues with these air packs.

 

[Recovry4x4]

Had that happen once. Rebuild took care of it.

 

[glcaines]

Never had any problems out of mine.

 

[militarysteel]

when you are hitting the breaks, is there a no no? like pumping them could that cause it to lock up if its one that is temperamental, another thing that gets my goat is dot5, i hate the price.

 

[Recovry4x4]

On mine it was like there was pedal resistance and once you pressed passed the resistance it was like jamming on the brakes. Rebuild fixed it.

 

[gimpyrobb]

Had that happen once. Rebuild took care of it.

Me too.


I don't think there are any "no-nos" but I do see a lot of people not draining their air tanks. The moisture in the air lines will rust up the insides of the air-packs and make them go bad quick!

 

[patracy]

Bingo gimp. That's why I spent $20 to add pull cable drains on mine. Best cheap mod yet.

 

[DieselBob]

Knock on wood I haven't had a problem with mine yet. 2 years and a couple hundred miles. I do drain the tanks religiously and squirt a small amount of air tool oil in it annually.

 

[DieselBob]

Whats an air pack? Thanks Jim

It's the brake booster unit.

 

[bugei]

powerstroken

one of the symptoms of an "improperly" rebuilt airpack is a hard pedal, and NO brakes. there is an error in the rebuild instructions in the tm, that causes this symptom. make sure if you are rebuilding them, that you make note of the "sticky" at the top of the duece section, that describes the error.

 

[cranetruck]

Lock-up may occur when the truck (brakes) aren't used very much. Non-use may cause the valves to stick.
Prevention means lubing now and then and/or using the truck more often.
My brakes were locked up one time back in '01 and resulted in a rebuild and the MVM article.
The error in the TM was first pointed out to me by David Doyle. The cup seal is shown backwards in the picture...
The lube oil is "hydraulic" or air tool oil equivalent to 10W engine oil in viscosity.

 

[FL_Frank]

The lube oil is "hydraulic" or air tool oil equivalent to 10W engine oil in viscosity.

Thank you very much for that tidbit!

(and the article too, of course)

-Frank

 

[stumps]

Bear in mind that all air-packs need the oil, but not all have an oil plug. On those newer air-packs without the oil plug, you have to either uncouple one end the "J" tube, and give it some oil, or uncouple the air inlet tube from the air pack, and give it some oil.

Those "J" tubes that don't have compression nuts on each end have an O-ring on the end without the nut that slides out when the other side is unscrewed. Be sure that the bore is clean of all paint and mud, and you probably will have to replace the O-ring to get a good seal.

-Chuck

 

[militarysteel]

how about some WD-40 ? squirting into the inlet like you said? how often does some lube fix a stuck air pack? should you always rebuild once it locks, just as a precaution even if lube fixed it?

 

[Junkyard Wars Crusher]

I have a question/comment related to this topic. I have occasionally added a small amount of air tool oil directly into the intake for the air compressor. I literally put in a “handful” at a time. I pour some oil into the palm of my hand and then I carefully place my cupped hand under the intake tube/port on the air compressor while the engine is running. The oil is sucked up into the compressor.

I have done this in the past when I noticed the air governor “sticking” and cycling repeatedly. It quickly remedied the governor problem. Does anyone know of any detrimental effects of this method?
It would seem that this would add a measure of air tool oil to the entire system, including the air pak right? I guess if you use your air powered windshield wipers that some of the oil could be exhausted from the wiper motor.

What say y’all?

 

[wdbtchr]

I added an automatic oiler to the outlet of the air tank on my DTC 8606 forklift to lube the air system. The throttle, creeper valve, and breaks get lubed constantly now.

 

[cranetruck]

I have a question/comment related to this topic. I have occasionally added a small amount of air tool oil directly into the intake for the air compressor. I literally put in a “handful” at a time. I pour some oil into the palm of my hand and then I carefully place my cupped hand under the intake tube/port on the air compressor while the engine is running. The oil is sucked up into the compressor.

I have done this in the past when I noticed the air governor “sticking” and cycling repeatedly. It quickly remedied the governor problem. Does anyone know of any detrimental effects of this method?
It would seem that this would add a measure of air tool oil to the entire system, including the air pak right? I guess if you use your air powered windshield wipers that some of the oil could be exhausted from the wiper motor.

What say y’all?

You may want to research this...here is one comment off a Donaldson filtration system promo (image below).
The oil in the airpak is eventually exhausted and will not effect other parts AFAIK.

 

[stumps]

You may want to research this...here is one comment off a Donaldson filtration system promo (image below).
The oil in the airpak is eventually exhausted and will not effect other parts AFAIK.

The reason you need to remove compressor crankcase oil from the air supply is it gets wet from the water in the hot compressed air, and emulsifies. It typically looks like mayonnaise in your water separator... not a good thing for the metal stuff down the air line.

Because the compressor feeds the wet and dry air tanks from the top of the tank, and draws off the air from the top of the tank, any air tool oil you feed into the compressor's inlet will get trapped by the air tanks long before it can find its way to the airpack. He really needs to feed the oil directly into the airpack's air inlet.

-Chuck

 

[Rustygears]

The reason you need to remove compressor crankcase oil from the air supply is it gets wet from the water in the hot compressed air, and emulsifies. It typically looks like mayonnaise in your water separator... not a good thing for the metal stuff down the air line.

Because the compressor feeds the wet and dry air tanks from the top of the tank, and draws off the air from the top of the tank, any air tool oil you feed into the compressor's inlet will get trapped by the air tanks long before it can find its way to the airpack. He really needs to feed the oil directly into the airpack's air inlet.

-Chuck

-Especially true on the A3, where all of it gets pulled out by the air dryer, if it isn't clogged by all the excess oil.

Also, feeding oil into the air compressor inlet is a good way to destroy the air compressor with hydraulic lock or even worse, to possibly detonate it if the oil combusts in a diesel cycle. This is a hazard with AC compressors used as air compressors. The excess refer lube oil in the intake lines burns from diesel combustion when sucked into the compressor.

 

[stumps]

You really don't have to worry about hydraulic lock in an air compressor because, unlike an internal combustion engine, compressors don't have a compression stroke where both valves are closed. Any liquid that fills the cylinder will just squirt out the exhaust valve and into the air tank.

Seems unlikely to me that dieseling would be a problem when you are only compressing the air to 120PSI at the most.... perhaps if the compressor was already really hot it might be.

-Chuck