Warpman89 Posted May 12, 2010 Share Posted May 12, 2010 Gentlemen, i am in a pickle. In the the process of installing a rebuilt 12 speed in my r688 tractor, my "professional" mechanic cut and disconnected all of the air lines that go to the air shifter on the transmission. Thankfully, i marked on the end by the shifter handle, but the ends that connect to the tranny are not marked, so i am not sure where they go exactly. I am writing this with the hope that someone somewhere has a diagram of air lines for such a truck, God willing. My Mack dealership had nothing, so i am turing to the experts on this forum for help. Any help or leads will be greatly appreciated.On a side note, through thorough cleaning, i have found that the bottom of the shifter knob/selector has numbers and letters for each air line and the same numbers are on the transmission. However, on the shifter selector knob, there is an "E" for one of the air lines, which has thrown me off. Otherwise, the 1-4 on the knob matches up with a 1-4 on the tranny, which im hoping is a light at the end of the tunnel. I hope there is someone on this forum that knows what i am talking about. If this doesnt make sense i can get pics 1 Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/ Share on other sites More sharing options...
GreenGiant2 Posted May 12, 2010 Share Posted May 12, 2010 Gentlemen, i am in a pickle. In the the process of installing a rebuilt 12 speed in my r688 tractor, my "professional" mechanic cut and disconnected all of the air lines that go to the air shifter on the transmission. Thankfully, i marked on the end by the shifter handle, but the ends that connect to the tranny are not marked, so i am not sure where they go exactly. I am writing this with the hope that someone somewhere has a diagram of air lines for such a truck, God willing. My Mack dealership had nothing, so i am turing to the experts on this forum for help. Any help or leads will be greatly appreciated.On a side note, through thorough cleaning, i have found that the bottom of the shifter knob/selector has numbers and letters for each air line and the same numbers are on the transmission. However, on the shifter selector knob, there is an "E" for one of the air lines, which has thrown me off. Otherwise, the 1-4 on the knob matches up with a 1-4 on the tranny, which im hoping is a light at the end of the tunnel. I hope there is someone on this forum that knows what i am talking about. If this doesnt make sense i can get picstaking a wild guess, i would say that E would stand for exhaust port.GG2 Quote We the unwilling, Lead by the unqualified, are doing the impossible, for the ungrateful. Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55001 Share on other sites More sharing options...
BAD DOG Posted May 12, 2010 Share Posted May 12, 2010 I've got the book right in front of me. Is it a TRTXL107 or a TRTXL1070 ? I'm not any good at sending this stuff on computer but I'll see if I can get my brother to scan it and post it for you in a little bit. Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55002 Share on other sites More sharing options...
Warpman89 Posted May 12, 2010 Author Share Posted May 12, 2010 (edited) Here's what i am talking about in the second paragraph:This is the bottom of the shifter knob, the numbers and letters are somewhat visible, 1,2,3,4, "S", and "E"This is the air shifter that goes on top of the tranny, it has 5 air line connections going to it, 4 of which are numberedThis is a diagram i made up, which links 1-4 on the tranny with 1-4 on the shifter knob, "S" on the shifter knob is already connected, leaving "E" without a destination.Does anyone know where "E" goes? and where does the extra connecter on the tranny labeled "4" go? any help would be greatly appreciatedBy the way, the weird shape at the bottol of my diagram is supposed to be the top of the tranny shifter, as it appears in the picture above it Edited May 12, 2010 by Warpman89 Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55003 Share on other sites More sharing options...
Rob Posted May 13, 2010 Share Posted May 13, 2010 Here's what i am talking about in the second paragraph:This is the bottom of the shifter knob, the numbers and letters are somewhat visible, 1,2,3,4, "S", and "E"This is the air shifter that goes on top of the tranny, it has 5 air line connections going to it, 4 of which are numberedThis is a diagram i made up, which links 1-4 on the tranny with 1-4 on the shifter knob, "S" on the shifter knob is already connected, leaving "E" without a destination.Does anyone know where "E" goes? and where does the extra connecter on the tranny labeled "4" go? any help would be greatly appreciatedBy the way, the weird shape at the bottol of my diagram is supposed to be the top of the tranny shifter, as it appears in the picture above itThe "E" is for exhaust. The line terminates into free space under the truck cab. It does not connect to anything.Cheap insurance is to rebuild that "Selectair" valve while you have the truck down. Parts are less than $20.00 from Mack.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55006 Share on other sites More sharing options...
BAD DOG Posted May 13, 2010 Share Posted May 13, 2010 Not having any luck posting the schematics for you but I followed your drawing and it matches my schematic in the book for the TRTXL1070 and the E on the shift knob is always the exhaust port on all 12 speeds I hope it works, I'm sorry I wasn't able to post the schematics I have for you . Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55010 Share on other sites More sharing options...
BAD DOG Posted May 13, 2010 Share Posted May 13, 2010 The "E" is for exhaust. The line terminates into free space under the truck cab. It does not connect to anything.Cheap insurance is to rebuild that "Selectair" valve while you have the truck down. Parts are less than $20.00 from Mack.Rob Yeah selectair kits are pretty cheap. I would also put an O-ring kit in the air shift cylinders on top of the transmission while I was at it too. Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55011 Share on other sites More sharing options...
Warpman89 Posted May 13, 2010 Author Share Posted May 13, 2010 Not having any luck posting the schematics for you but I followed your drawing and it matches my schematic in the book for the TRTXL1070 and the E on the shift knob is always the exhaust port on all 12 speeds I hope it works, I'm sorry I wasn't able to post the schematics I have for you .Thank You! I am still unsure of one port on the top of the transmission part. On my diagram, I labeled it "5", although it had no number. It is actually part of the number "4" port. Do you have any idea what this is for and more importantly where it goes? Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55047 Share on other sites More sharing options...
Warpman89 Posted May 13, 2010 Author Share Posted May 13, 2010 I've got the book right in front of me. Is it a TRTXL107 or a TRTXL1070 ? I'm not any good at sending this stuff on computer but I'll see if I can get my brother to scan it and post it for you in a little bit.TRTXL1070B Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55069 Share on other sites More sharing options...
counterman6 Posted May 13, 2010 Share Posted May 13, 2010 (edited) TRTXL1070BThe line you have labled number five should go to a limiting valve on the intake manifold.I hope this helps,Phil Edited May 13, 2010 by counterman6 Quote Thanks,Philphil@globaltrucktraders.comwww.globaltrucktraders.com603-239-7008 Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55078 Share on other sites More sharing options...
BAD DOG Posted May 16, 2010 Share Posted May 16, 2010 How did you make out with your air line hookup on the tranny, did it work? Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55254 Share on other sites More sharing options...
Warpman89 Posted May 18, 2010 Author Share Posted May 18, 2010 yup, she's almost all back together now and all the air lines are back where they belongthanks to all replies Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-55345 Share on other sites More sharing options...
mackniac Posted October 12, 2012 Share Posted October 12, 2012 HI !Is it normal for the E port (exhaust) to leak all the time when the tranny is on neutral and the selectair knob is also on neutral ( there is always a hiss of air under the cab , then if I select D or H or Reverse it stop hissing under the cab . Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141372 Share on other sites More sharing options...
e9500v8 Posted October 13, 2012 Share Posted October 13, 2012 I am guessing your shift knob needs rebuilt. Mack has a kit but it is outrageously priced. PAI has it for around 50 bucks I think Mack gets around 100. Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141456 Share on other sites More sharing options...
mackniac Posted October 15, 2012 Share Posted October 15, 2012 HI !Thank you I will try to find-out what is the kit part #is it PAI INDUSTRIES by any chances ? Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141805 Share on other sites More sharing options...
just macks Posted October 15, 2012 Share Posted October 15, 2012 Those trannies are expensive to repair, how much did you invest in repairing it? Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141812 Share on other sites More sharing options...
mackniac Posted October 15, 2012 Share Posted October 15, 2012 HI !The tranny is fine ( at least all goes good ) but the only problem I have with it is the hissing , the rest iswell and good running . Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141816 Share on other sites More sharing options...
rsb502 Posted October 16, 2012 Share Posted October 16, 2012 Yeah E for exhaust, and no air shouldnt leak out of the exhaust in any position, your shifter needs to be recuilt and the kit at Mack was $26 when I got it for mine.Warpman, make sure you supply clean dry air to that trans, it will save you some issues down the road like sticky shift solenoids and slow or erratic shifting. Mine had a spin on air filter on the trans that I changed every time I changed the oil, I also added an Air dryer (bendix AD-9 $175) it makes the whole air system happier and it cost you about $140 to get a new purge valve and a dessicant cartridge to rebuild it so I did mine once a year, Bendix recommends once a year or every 100k mi. I wish you luck thats the best transmission Makc ever built in my mind you always have the right gear with that one. Quote "Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin"If your gonna be STUPID, you gotta be TOUGH" "You cant always get what you want, but if you try sometimes you get what you need" Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141863 Share on other sites More sharing options...
mackniac Posted October 16, 2012 Share Posted October 16, 2012 Hi !84 Superdog , so what you are saying is that you are adding another air dryer over and above the one on the truck only for the tranny ?I search for the rebuilding kit for that tranny and I can't find any p/n anywhere , anyone knows the p/n please Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141919 Share on other sites More sharing options...
rsb502 Posted October 17, 2012 Share Posted October 17, 2012 Hi !84 Superdog , so what you are saying is that you are adding another air dryer over and above the one on the truck only for the tranny ?I search for the rebuilding kit for that tranny and I can't find any p/n anywhere , anyone knows the p/n pleaseNo my truck did not have any form of air dryer, most 80's trucks didnt have them, I added one in line from the compressor to the tank and it all but completely eliminated any moisture in my air system, and that is a good thing with a 12 spd. oh.... and air brakes! Quote "Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin"If your gonna be STUPID, you gotta be TOUGH" "You cant always get what you want, but if you try sometimes you get what you need" Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141981 Share on other sites More sharing options...
turckster Posted October 17, 2012 Share Posted October 17, 2012 (edited) TRTXL107 Prior to Serial Number 9G90711. Air Control Reference Locator 2. Air Control Select Lever 3. Gear Select Lever 4. Quick Release Valve 5. Exhaust 6. Reverse Shift Cylinder 7. Port No. 4 8. Port No. 3 9. Back-Up Switch (normally open) 10. Amber Indicator Light (on in reverse) 11. Pressure Reducing Valve (60 psi delivery) 12. Port No. 2 TRTXL1070, Serial Number 8S6798 and later 12. Hi/Direct Shift Cylinder 13. Pressure Reducing Valve (70 psi delivery) 14. Air Filter 15. Air Supply 16. Selectair Valve 17. Exhaust A. Section A - A B. Piston Port C. Pressure D. Exhaust 11. Port No. 1 Hope this helps Edited October 17, 2012 by turckster 1 Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-141990 Share on other sites More sharing options...
e9500v8 Posted October 17, 2012 Share Posted October 17, 2012 Kit number is 14rc1131 that is the mack number and the pai number is FKT1148 Hope this helps you out! Quote Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-142028 Share on other sites More sharing options...
mackniac Posted October 17, 2012 Share Posted October 17, 2012 thank you fotr all the help I will check all that . Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-142036 Share on other sites More sharing options...
mackniac Posted October 18, 2012 Share Posted October 18, 2012 Hi !is the reducing air valve is adjustable or are they are factory set ?I see some tranny needs 60 psi some need 70 psi ! Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-142148 Share on other sites More sharing options...
rsb502 Posted October 19, 2012 Share Posted October 19, 2012 Hi !is the reducing air valve is adjustable or are they are factory set ?I see some tranny needs 60 psi some need 70 psi !could be either, most are adjustable,put a guage in line adjust it then remove the guage, or just leave it there if you dont want to remove it, bendix has preset regulators you can get at most truck parts places for less than $20. Quote "Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin"If your gonna be STUPID, you gotta be TOUGH" "You cant always get what you want, but if you try sometimes you get what you need" Link to comment https://www.bigmacktrucks.com/topic/13871-calling-all-mack-12-speed-experts/#findComment-142238 Share on other sites More sharing options...
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