MY Airpack Rebuild with Photos!

[scootertrs]

About 1 and a half year ago I replaced both my master cylinder and my airpack with NOS units. Used DOT 5 and all was well or so I thought... yesterday I was taking my Deuce fire truck to get a paint touch up when I saw a river of Dot 5 coming from the vent tube.. maybe it was an old unit that sat on a shelf for many years or maybe luck of the draw... Either way, I am rebuilding this one, making sure it is done right... Moral of this story... just because it is new, it does not mean it will be troublefree. Understand, mine did not come from Memphis.

http://www.steelsoldiers.com/showthread.php?3229-Deuce-Power-Bleeder-R4x4-Style




If money is not a problem (and it sounds like maybe it isn't) you can just buy a new airpack. http://www.memphisequipment.com/PartsDetail.aspx?id=10000259
(Memphis is just one parts dealer, I'm sure others have them)

 

[scootertrs]

Wow... just took my air pack and master apart... I took a lot of photos... if somene feels like they would like to see them, I can either send you a cd or post them. I don't know what max posing capacities are, but we are over the 216mb file size in my computer, but will fit on a cd just fine. I will be glad to dump on a cd and send if some member needs help. (no charge, just allow time-I will get it to you-I am a firm believer that what goes around, comes around) But I do not want to steal thunder from this great writeup (of biblical proportions) merely assist... if he (she) deems me worthy. please pm me with a snail mail address.

Of concern, are, how do I clean the crud off without damaging reuseable parts. Some of this stuff is real nasty... actualy loks like somebody went into an Alaskan outhouse, ladled out spme of the contents, and put it into the deuce's braking system... funny, I would swear I smell wienerschnizel in the mix as I pour it out... -

On a separate topic... what is the best way to clean these parts up? I know what is good for steel is not good for aluminum, an neither is good for rubber or leather... a little help ... please???

thank you and God Bless, Merry Christmas to all.

Raul

BTW echoing several other posters... I cannot imagine owning one of these beasts without our support group... Wow!!!! Thank you all.

 

[JCKnife]

Having rebuilt my airpack and bled the system twice, I had a firm pedal for a few days and then nothing--all the way to the floor. Also I was hearing a hissing at the firewall (presumably the vent line) that was not present before. So I must have screwed something up in the rebuild. I have no idea what it was. So rather than throw good money after bad and try it again, I decided to pick up a NOS airpack from a local vendor. I got a good deal. From this tag, do you suppose this is a 1993 manufacture date?



The desiccant pack that was in with it is HUGE. I'm going to hang on to that.

 

[scootertrs]

I don't know if or what the airpack had on the rebuild... If the pedal went to the floor, I would suspect the master cylinder. Either way, I have learned to believe that new... usually means New to Me -... I guess like Emos used to say about underwear... I chose to rebuild my own... this way. when (and if) it fails, I can look in the mirror and point right at the guy that screwed up. Try to follow the rebuild instructions... build yourself a backup-you have a core now-do not cut corners... These trucks do not get driven that often, so I try to get them worked out once a week if possible. Good luck, and God Bless +Happy new year.

 

[blisters13]

deleted

 

[brianp454]

Sorry to hear you had trouble. I'm planning to rebuild mine next week also. Was it the short or long version?

You could share the pics using a dropbox folder. PM me if you'd like the details on how to do it. If you don't already have online backup of things you don't want to lose it's a good idea.

Wow... just took my air pack and master apart... I took a lot of photos... if somene feels like they would like to see them, I can either send you a cd or post them. I don't know what max posing capacities are, but we are over the 216mb file size in my computer, but will fit on a cd just fine. I will be glad to dump on a cd and send if some member needs help. (no charge, just allow time-I will get it to you-I am a firm believer that what goes around, comes around) But I do not want to steal thunder from this great writeup (of biblical proportions) merely assist... if he (she) deems me worthy. please pm me with a snail mail address.

Of concern, are, how do I clean the crud off without damaging reuseable parts. Some of this stuff is real nasty... actualy loks like somebody went into an Alaskan outhouse, ladled out spme of the contents, and put it into the deuce's braking system... funny, I would swear I smell wienerschnizel in the mix as I pour it out... -

On a separate topic... what is the best way to clean these parts up? I know what is good for steel is not good for aluminum, an neither is good for rubber or leather... a little help ... please???

thank you and God Bless, Merry Christmas to all.

Raul

BTW echoing several other posters... I cannot imagine owning one of these beasts without our support group... Wow!!!! Thank you all.

 

[DeucesWild11]

Blisters, i read your original post but now since it's deleted did you fix your problem?

 

[blisters13]

Blisters, i read your original post but now since it's deleted did you fix your problem?

Yes, problem fixed with a $500 airpack.

I think I honed the hydraulic cylinder so much that the hydraulic piston (with check valve) was getting cocked (crooked) in the cylinder and sticking, preventing the air piston rod from advancing the hydraulic piston and applying pressure assistance.

A friend who has worked on these since the 1970's told me I probably got a rebuild kit with the next size piston diameter. I never heard of that; he said the parts house is supposed to ask you what oversize you want, just like engine cylinder pistons. That would only apply, of course, if you had a machine shop bore it out to a specific oversize.

 

[JCKnife]

I replaced my rebuilt (long) airpack yesterday with the new (short) one. The one I had rebuilt, spilled copious amounts of brake fluid out the air side, so clearly I either did something wrong in my rebuild, or got a faulty part. It's baffling me, because I followed 2 sets of instructions (the TM and that magazine article) plus this thread and all seemed to make sense. BUT, regardless, the new one is on now. Bled the brakes and felt a firm pedal. Fully expect to have to bleed them again but we'll see.

Maybe this has been discused but it appears that the purple Dot 5 turns yellow when exposed to air? The fluid in my pressure bleeder is still purple but the stuff that came out is yellow, as is the residue around the lip of my pressure bleeder (where it has spilled and collected on the outside).

 

[brianp454]

Can you forward me the magazine article of a link for the short air pac rebuild? I found one for the long version, but not the short.

Yes, DOT 5 normally turns yellowish after some time period. I've made the same observation and the motorcycle community has numerous similar observations.

I replaced my rebuilt (long) airpack yesterday with the new (short) one. The one I had rebuilt, spilled copious amounts of brake fluid out the air side, so clearly I either did something wrong in my rebuild, or got a faulty part. It's baffling me, because I followed 2 sets of instructions (the TM and that magazine article) plus this thread and all seemed to make sense. BUT, regardless, the new one is on now. Bled the brakes and felt a firm pedal. Fully expect to have to bleed them again but we'll see.

Maybe this has been discused but it appears that the purple Dot 5 turns yellow when exposed to air? The fluid in my pressure bleeder is still purple but the stuff that came out is yellow, as is the residue around the lip of my pressure bleeder (where it has spilled and collected on the outside).

 

[JCKnife]

Can you forward me the magazine article of a link for the short air pac rebuild? I found one for the long version, but not the short.

The article I referenced was for the older, long airpack. I'm not aware of a rebuild kit for the newer / shorter ones, nor any instructions. I bought a NOS short one and installed it.

 

[Yarz]

the shortest version is my brakes are stuck on .

The brake lights are on so that makes me think the problem is in the airpack. If it was just a shoe sticking, the lights wouldnt be activated. The pedal is hard to depress but i can hear the air releasing when you let of the pedal.

WTF is going on?

Did this happen after you had the airpack apart? I recently rebuilt mine and had the same problem. Turned out I had one part in backwards. Took about ten minutes to set it right and the problem went away immediately.

Which part was this? The seal that some manuals had wrong? I'm pretty sure I got that one in right..

I just rebuilt my master cylinder and air pack, since I was redoing all of the brake lines. Neither really needed it, but I didn't know that until I opened them, and then decided to rebuild anyhow.

Now, I hear the pressure vent when releasing the pedal, and the drivers side glad-hand only has air when pushing the pedal. After some test pushing the pedal, my brakes will lock up, and the pedal will get hard, which I assume is due to air pressure leaking past something inside the air pack. To release them, I crack a bleeder. I didn't think to check the lights to confirm it's the air-pack.

I haven't fully bled them yet because of this, if that makes a difference.

I figured I have to open it up again, but would really prefer to have some idea of what to look for, if possible.

I'd really like to get this thing drivable again, as it's sat since December with me working on it when weather and time permit. Hopefully this thread isn't too old to be seen. Off to do some more reading..

 

[gringeltaube]

....... After some test pushing the pedal, my brakes will lock up, and the pedal will get hard, which I assume is due to air pressure leaking past something inside the air pack. To release them, I crack a bleeder. ...

It may be as simple as the MC-piston not fully returning? Read this post... and a few more, down to the end of that thread.



G.

 

[Yarz]

A NOS MC I installed did exactly that, so I rebuild the old one and re-installed it. It's returning quickly and completely. Thanks for the idea

 

[Motorcar]

I know this is an old thread but still quite valuable. I want to say thank you to the OP and all other contributors to the thread. After years of no problem operation my air-pak finally took a dive. This thread gave me the info I needed to get the job done. I got the kit from Erik's and did the rebuild myself. Thanks again to all.

 

[DeucesWild11]

No problem, glad it helped you out! My airpack is now venting air into the overflow tube or "slobber tube" in the engine compartment so I now have to take out and rebuild again. Oh well such is life with an old deuce, wouldn't change it for anything!����

 

[yolner]

So I have this long airpack that I'm rebuilding and I painted this end of the cylinder where the gasket is supposed to sit. Should I strip that part back to raw steel or will the gasket seal even if the surface is painted?

 

[rustystud]

So I have this long airpack that I'm rebuilding and I painted this end of the cylinder where the gasket is supposed to sit. Should I strip that part back to raw steel or will the gasket seal even if the surface is painted?View attachment 650196

I hope this picture is the "before" picture ! The paint won't hurt anything here though.

 

[yolner]

I hope this picture is the "before" picture ! The paint won't hurt anything here though.

No, I just used a picture from the first page to show what I was talking about. Unfortunately now that I painted the air cylinder I found a dent in the side which makes the whole dang thing useless. I hate how hard it is to find good cores that can be rebuilt. Just bought 2 and one was completely full of rust and this one had the dent.

 

[DeucesWild11]

I was going to say wow that looks as in as bad a shape as mine was! Lol. I think you'll be OK if you painted it so long as you got down to bare metal.

On another note I think I found the piece that's the culprit for most Airpack problems. See pics. Not sure what this piece is called but I believe its a valve that controls both the build up and release of the air in the airpack. So like my original problem with the brakes dragging this piece was stuck closed so the air wouldn't release. Just recently I had an issue where I couldn't build up the air pressure in the truck. I went crazy looking for air leaks and then took apart the Airpack and found this piece to be all corroded and suck Open which was just constantly releasing the air.

This is a great find because if your brakes are dragging or can't build up pressure, you can just unbolt this piece while the Airpack is still on the truck. That way you don't have to do a full rebuild to fix your problem!