M211 airpack questions

[davesgmc]

Well, It got warm enough to go out and work on Elmo this weekend. I decided I was going to at least make sure the breakes were working on him. The master cylinder as almost completely dry. I filled it full of fluid and started looking for leaks. I was told when I bought him that the previous owner installed all new wheel cylinders and a master cylinder. Well, The right front lower wheel cylinde is leaking very bad. I went ahead and bled the rest of the system, they all seem to hold fine. I pulled the right fornt wheel. The lug nuts were VERY tight and rusted. Nothing that a bit of heat from a torch, a 6 foot cheater bar, and my 300 pounds standing on the end of it couldnt get loose. I took the leaking wheel cylinder out, It had some gunk in it and a slight bit of rust in it. I cleaned it out real well, put it back together, and it works fine now. Now the whole hydralic system is working fine, so I thought..............

I put air to the system via an adaptor and my shop air hose. IT stops fine. Although its not running and the trans is still trashed, i was just pushing it back and forth in the driveway to test the brakes. BUT after about 2-3 stops they are locked up!

When the air is released and you stomp on the brakes one more time, they release and work fine. I checked the air pack, it is venting air just fine, the dash valve is working ok too. I would assume that the air pack internal valving is not working? Is there a place to lube it and a simple way to fix it without removing it? Or anything I should try before removing and and trying to rebuild it? It does look like a rebuilt unit,. as its not as crusty as all the other stuff mounted around it. I understand that the rebuild kits a n/a now.

What gets me is that after the airis released it wont immediately roll, but after you stomp on the brake pedal one more time, then it roills fine. Sould I remove the inlet line and put some light oil in it and bang on it with a hammer?

 

[acetomatoco]

Are you sure your Mico Brake is released?

 

[acetomatoco]

The oil for use in the air side of the booster is OHT... air cylinder oil and should be introduced in 1/2 OZ quantity every six months.. be sure to drain all air pressure before removing tube to put oil in....ACE

 

[acetomatoco]

I would check to see if the system is still pressurized when it will not roll, by opening a bleeder on one wheel... It may just be a coupla lazy shoe return springs... ACE

 

[firefox]

As was posted, ONLY use OHT, which is not petroleum based oil, or you will have problems.
Remove the 1/8 pipe plug from the rear of the larger cylinder of the air pack and squirt 3 shots of OHT in there. This is per an article from PS mag which is somewhere on this site.

 

[davesgmc]

OHT? what is it? where can i get it?

 

[davesgmc]

oh and yeah, I am sure the micro lock is releasing, and is all wheels locked up, not just one ro two, Had the whole thing off the ground on stands to check it today.

There is still pressure when they are locked up, i opened a bleeder screw and a bit came out, then that wheel turned. I also gave the air pack a few taps with a hammer an it did start to release, but not all the way

 

[doghead]

OHT is mentioned in this PS mag article. Hydraulic Fluid, Petroleum Base for Preservation and Operation (OHT) MIL-H-6083

http://www.steelsoldiers.com/index....rpak_lube&name=gallery&include=view_photo.php


It is listed here also, about 3/4 of the way down the page.
http://www.globalsecurity.org/military/library/policy/army/fm/9-207/appa.htm

If you google"oht mil-h-6083" you will find that it appears to be hydraulic fluid.

MSDS, http://msds.ogden.disa.mil/msds/owa/web_msds.display?imsdsnr=125471

 

[acetomatoco]

There is no plug on the M211 Pac.. unlike the M35 Pac.. You have to remove the air tube going to the back of the pac and indroduce the oht into the hole there...Spruce Mountain Surplus was selling the OHT in small bottles.. probably www.sprucemountainsurplus.com as I remember it.. ACE

 

[firefox]

Now I am worried, I just got a replacement airpack from alpha heaven for my M211 and it has
the plug in the back. I am wondering if this wasn't an upgrade. Any one know?

 

[doghead]

Did you see the pics in this post? maybe they can help you. http://www.steelsoldiers.com/index.php?name=PNphpBB2&file=viewtopic&t=10188&highlight=oht

 

[mo-mudder]

Mine also has the plug on the back, but it was gone-thru by Memphis equipment years ago. Probably an upgrade of some sorts. Have you contacted them to see if they have any units there? But judging by their price on a new centersection ($900), I think they believe that we MV-er's are millionaires.

 

[davesgmc]

there is a plug in the back of the pack on mine. The MSDS sheet prety much describe the same thing as marvel mystery oil. I went ahead and gave a few squirts of it in there and removed the inlet air line and put some int there too. didnt make much of a difference, but this this has been sitting for a LONG time. I would imagine that it is all rusted and stuck inside. I will go ahead and take it apart (someday) and see if I can free it up, hopefully.

 

[firefox]

I believe that someone said that the rebuild kit for M35 or the M54 had all the right parts for the M211 except for one seal, but I can't find the email.

 

[davesgmc]

probably the ONE seal that I would need huh?