farmer52

Excellent show and venue.  Too bad it was so stinkin' hot but at least the A/C in the museum was working.  Kudos to Doug and the Museum staff for their efforts.  Always something "new" to see at the Museum.

Affirmative...I plan to arrive around noon on Thursday and depart Saturday afternoon.  Going to "rough it" and sleep in the trailer both nights.  Not sure if Capt. Barry will be there.

You all missed a great Trucktoberfest on Saturday.  But it was HOT!

If you license it as an "antique", most states restrict the usage (i.e. parades, shows, etc.) but cannot be used "for hire" or commercial service.  Check with your state BMV to be sure.

On ‎9‎/‎5‎/‎2016 at 10:11 PM, BC Mack said:

 

have someone make a full brake application, when stabilised no more than 3psi per minute air loss is allowed, again go around and check for leaks.... before your helper's leg spasms..!!

Sean,

I did a full brake application for about five (5) minutes (my leg was getting tired) and the needles never moved.

I think I found the cause of my air leaks.  First there is to be a check valve in the line from the RH primary tank to the LH tank (at the LH tank).  I cannot see one, unless it is an internal check valve in the line.  That might resolve my "parked" leak down.  Now for the big one, my moving leak (hopefully) is at the trailer gladhand port on the trailer.  I replaced the gladhand seals but there is still a major air leak behind the clamping mechanism (don't know the correct nomenclature).  Is there a gasket/o-ring between the stamped steel bracket and casting?  If so is it replaceable?  Or is the glandhand seal the "gasket"?  I searched the Great Dane parts catalog and Sloan but I do not see anything concerning a gasket/seal.  Anyone know what I am talking about?  Or do I need to replace the complete "port" on the trailer?  See attached pic, do I need to loosen two (2) torx screws and reposition the gladhand seal?

UPDATE: Being the inquisitive engineer I could not sit back and do nothing.  So I removed the torx screws and the hex bolt (at the top of the picture).  This allowed movement of the red bracket but not able to remove (round head rivet at the bottom of the bracket).  But I could see behind the bracket and there is no gasket.  I removed the gladhand seal, cleaned the casting and seal, used white lithium grease, and reinstalled the seal and screws/bolt...NO LEAK.  So now comes the road test on Friday.  Stay tuned for the continuing saga of "Roll Hauler Express Air Leaks".

BTW, I checked the tractor brake cans and there are no leaks.  In all the "excitement" I forgot to check the trailer.  I will do that on Thursday.

Thanks Rob and Sean for the diagnostic info.  Not sure if I will get it done this week before I leave for Trucktoberfest.  It is only me, myself, and I but will do my best to check things and report back with the results.  Maybe I can enlist the help from someone at the Museum on Friday.  Hmmm, wonder who that might be?  And I will take a spray bottle of soapy water with me.

BTW, I don't think there is a check valve between the compressor and primary air tank.  The parts book does not show one.  I will know when I break the line at the compressor.

The low air alarm works, at least when building air pressure.  I think the buzzer goes off about 60psi.  I will confirm on the down side.

I just hope the leak is obvious and simple to repair.  I would add "cheap" but that may be too much to ask.

15 minutes ago, gearhead204 said:

Ken chalk the wheels and release the brakes then feel around the air cans (double chambered only) and see if any air is escaping from the bleed holes.

 I'm thinking maybe you have two problems and a blown maxi diaphragm could be your moving (driving) air leak. and then a smaller one for the other loss.

Also have you removed the compressor discharge line to make sure air isn't bleeding back thru a bad check valve in the primary air tank?

 

Rob,

Thanks for the suggestions on what/where to check.  I will try to check them this week before I leave for Allentown or Friday when I am at the Museum for Trucktoberfest.

FWIW, I had this issue (leak down while driving) before both tanks were replaced.  I have not noticed any change in the leak down rate since.  Although both tanks were in "poor condition", I was hoping my air leak was resolved when changing the tanks.

16 minutes ago, AZB755V8 said:

I would say that a 4psi drop an hour is Great!

I am loosing air at the rate of ~15psi per hour sitting and 60+psi per hour driving.

1 hour ago, gearhead204 said:

Ken, check the trans breather and see if you feel or hear air coming from it, a range piston air leak can cause lots of hours of misery  while looking every place else on the truck. 6 hours to loose 80-100 lbs. will be a pain to find, also does the mh have air operated functions in the heater box? I know my superliner looses air fairly quick because of a leaky piston  for the defroster door.  

T2050 transmission so no range piston.  Yes the HVAC doors are air operated.  What about the issue of loosing more air while I am driving (~30psi in 20 minutes =1.5psi per minute)?  Sitting the air leak is way less at approximately 0.27777psi per minute.  Or should I just say "fluff it" and move on?

Went to the Shortway Truck Show; Washingtonville, PA on Saturday, nice turnout of trucks and show (great ice cream BTW).  The primary air (green needle) after six (6) hours sitting was down to about 20psi (secondary red needle at about 90psi).  So still have an air leak.  Someone mentioned perhaps the brake "cans" are leaking.  Does this make sense while the truck is parked?  Is there an easy way to check them?  Soapy water?  Any particular area to spray?  I replaced the dash valves last year and there are no leaks there.  Guessing it is outside somewhere since I cannot hear air leaking.  Also while driving the air will drop (both needles at the same rate) from ~120psi to 90psi in 20-30 minutes (then the compressor kicks in and recharges).  Thanks for any suggestions/help.

Yea, I was curious who was the "crazy biker" trying to pass me.  I did not remember pulling out in front of anyone.  Sorry I did not have more time to talk.  I wanted to get south of State College before the Pedo State game was over.

7 hours ago, Tbear said:

Ok Jhancock says the red knob should not pop out when you pull the yellow you say it should I'm confused!        

My old freightliner the red always come out with the yellow my Mack is about 50/50 my trailer is a2007 Kaufman. I'm thinking the older trucks and trailers are the way JHancock says and maybe the newer stuff is like my old freightliner.The reason I think that is I had a delevery from saia and when that guy set his brakes I heard one pull but saw 2 dust could 1 from the truck and 1from the trailer at the same time. Let me know . 

FWIW When I pull the yellow knob, I get a "puff" of air from both the tractor and trailer.  But the red knob does not pop out.

1 hour ago, Hobert62 said:

There is also supposed to be an allusive black superliner in the area that likes to do burnouts but I haven't ran across that one yet.  

Back in Black Al?

2 hours ago, david wild said:

I would like to see more pictures of your truck ????

David,

Some older pics are in my gallery

http://www.bigmacktrucks.com/gallery/album/1033-1992-mh612/

Bob,

Thanks!  At first I thought it was a snow thrower then realized it is a reel mower.  Looks easier, simpler, and probably less expensive than working on a Mack truck.

A question for the Mack Museum and its staff to answer.  Wasn't the Gen I Superliner manufactured in Hayward?  Did Hayward have a design studio?

7 hours ago, AZB755V8 said:

I got actually three tanks, one for a spare, from, www.truck parts inventory.com  for $125 each.

Thanks for the link.  I will take a look.  This morning I decided to use the new tank I bought rather than "squirrel it away".  I disconnected the air lines and removed the fittings from the old tank.  I need to install the fittings, plug four (4) ports, and then it is ready for installation.  I was going to powder coat it but will just install with "factory" paint.  Hey the original one lasted almost 25 years.  So the new one will likely outlast me.  As with the RH tank, I will put a rubberized strap between the aluminum step and tank.

6 hours ago, j hancock said:

The red knob should not be popping with the application of the yellow knob.

There probably is a time for brake release but 3 seconds seems OK for the air to overcome the spring brakes.  5 seconds maybe a little long?

My red knob does not pop out with the yellow knob so I think my system is functioning correctly.  I was only guessing at the time delay but it is a few seconds before the trailer brakes release.

Thanks everyone for the comments and information.

5 hours ago, carlotpilot said:

if your trailer has maxi-spring brakes yes pulling the red knob is what locks your trailer brakes when you are parked. a properly working system will automatically kick the red valve out when you pull the yellow one. however if you have a really old trlr.which does not have maxi-spring brakes then your trailer brakes will only hold when parked until the air in the tank under the trailer leaks off

My trailer is a 2005 Great Dane single axle.  When I pull out the yellow parking valve the trailer purges air and the red trailer valve does not automatically pop out.  Also, I notice when I release (push in) the yellow parking valve I cannot move until the trailer brakes release.  There is about a 3-5 second delay.  Is this normal?

New replacement (22QE31179M) tank bought from Barry but has several more ports and does not match exactly.  I can make it work if I can't find a nice used tank.

We have a movie star...one of our own...can you guess who?

https://www.youtube.com/watch?v=Gc6anukym9s

https://www.youtube.com/watch?v=ENCQNfSIHuI

Barry - Great show (as always).  And if it was not hot enough...there was the "flame thrower" that raised the temperature another 20 degrees or more.  Did I miss the BMT nooner?

Larry - congrats!  You scored two (2) pics.  If you need someone to spend the gift certificate...give me a call.

Air leak identified - LH air tank between tank and step...duh!

I was not able to drive the "roll hauler" in a deep or cement pond so I got out the trusty water/soap bottle.  Sprayed all the fittings and then soaked the tank at the step bracket (see photo).  I put my ear to the area and even before the bubbles started I could hear a slight air leak.  The bubbles confirmed what I suspected.  So definitely in the market for a nice used LH steel tank.

Still need an answer to my question...when parking the tractor-trailer combination, do I just pull the yellow knob and leave the red and blue knobs pushed in?  The red knob states "Not for parking" so I never pull it when connected to the trailer.

Thanks for the suggestions.

Have you checked the spray pattern of the nozzle?  If it is burning in a small area outside the piston bowl, that might indicate a poor spray pattern.

Still looking for a nice used LH single chamber steel air tank (part number 22QE1269M or 22QE4907M).  I will be at Trucktoberfest, Hagerstown Power Day, Winchester, and Gerhart's.

Carl - I may need to contact Dave.  Midway tanks are gone.