MACKTRUCKS4 Posted March 28, 2009 Share Posted March 28, 2009 I have a 12 spd. (1070B) in my superliner. The problem I have is I have air leaking out of the vent in the high-low cylinder on top of the trans. I've rebuilt all the shift rails and pistons, checked all the plumbing, rebuilt the selector valve, changed the diversion valves, and can't seam to get the air to stop leaking. It only leaks when the selector is in direct, neutral, or reverse. It stops leaking when it's in high. I'm ready to blow it up. I need someone good with transmissions. Quote Live every day like it's your last, because one of these days, it will be. Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/ Share on other sites More sharing options...
fjh Posted March 28, 2009 Share Posted March 28, 2009 I have a 12 spd. (1070B) in my superliner. The problem I have is I have air leaking out of the vent in the high-low cylinder on top of the trans. I've rebuilt all the shift rails and pistons, checked all the plumbing, rebuilt the selector valve, changed the diversion valves, and can't seam to get the air to stop leaking. It only leaks when the selector is in direct, neutral, or reverse. It stops leaking when it's in high. I'm ready to blow it up. I need someone good with transmissions. Make sure you have the outer cylinder in corectly the snapring towards the rear!just pull the cylinder off in the truck and check it!also disconect the touque limit line from the reversing relay at the engine and plug it! both ways! Quote Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32713 Share on other sites More sharing options...
Swishy Posted March 28, 2009 Share Posted March 28, 2009 MT4GuddayM8Jist my 2 cents worth (TAX included) from the udder side of the worldQ: Did U apply sum lubricant to the 'O'rings in shift cylinder?Is the air escaping around the piston shaft?Could also B from the splitter contols on stikif these get dry they can let air escape into rong port @ the rong timeCya§wishyHasBeen Quote Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32715 Share on other sites More sharing options...
MACKTRUCKS4 Posted March 29, 2009 Author Share Posted March 29, 2009 I have all the rebuild manuals for mack transmissions that a friend gave me. With them, I made sure I put them together right. I tried to put it together wrong and you can't. I used mack o ring lube when I put it together. The torque limit lines are blocked. I think it may be the selector valve. I rebuilt it but it may be worn so I think I will put a new one on. I will order one on monday. Quote Live every day like it's your last, because one of these days, it will be. Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32772 Share on other sites More sharing options...
Rob Posted March 29, 2009 Share Posted March 29, 2009 I have all the rebuild manuals for mack transmissions that a friend gave me. With them, I made sure I put them together right. I tried to put it together wrong and you can't. I used mack o ring lube when I put it together. The torque limit lines are blocked. I think it may be the selector valve. I rebuilt it but it may be worn so I think I will put a new one on. I will order one on monday.PAI's complete "selectair" valve is not out of line on price as I think mine was about $60.00. I did not use it as I actually "boiled" mine in hot water, (yes, on the stove) to clean the accumulated garbage/buildup from it. It works as new now. Mine had probably never had the air filter changed in it's lifetime, (exaggeration).My shift cylinder kept leaking internally around the hi/low piston internal to the transmission. I found it by removing only one top cover bolt and it was like a tornado through a keyhole from the air escaping. I then removed the shift cover, tore it completely down again, boiled it, (same way on the stove), then honed the cylinder with a small cylinder hone and boiled it again. It was then put back together without any problems, (so far). I guess now you can see why "Momma" gets so angry with me. At least I changed the water before boiling the hot dogs in the same pan.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/8822-problem-with-12-spd/#findComment-32776 Share on other sites More sharing options...
MACKTRUCKS4 Posted March 29, 2009 Author Share Posted March 29, 2009 My air is leaking "only" from the vent in the bottom of the high-low cylinder. And because I replaced all internal parts, I think it may be the selector valve, which I only rebuilt. Quote Live every day like it's your last, because one of these days, it will be. Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32778 Share on other sites More sharing options...
Bollweevil Posted March 29, 2009 Share Posted March 29, 2009 PAI's complete "selectair" valve is not out of line on price as I think mine was about $60.00. I did not use it as I actually "boiled" mine in hot water, (yes, on the stove) to clean the accumulated garbage/buildup from it. It works as new now. Mine had probably never had the air filter changed in it's lifetime, (exaggeration).My shift cylinder kept leaking internally around the hi/low piston internal to the transmission. I found it by removing only one top cover bolt and it was like a tornado through a keyhole from the air escaping. I then removed the shift cover, tore it completely down again, boiled it, (same way on the stove), then honed the cylinder with a small cylinder hone and boiled it again. It was then put back together without any problems, (so far). I guess now you can see why "Momma" gets so angry with me. At least I changed the water before boiling the hot dogs in the same pan.RobIt works very well on lawn mower carb's also, Just a suggestion, but if you boil the hot dogs first you won't have to change the water. And as an added benefit, you can also clean and lubricate the parts at the same time. If you save the water to wash your hands afterward they will smell like hot dogs and she won't complain about you coming in the house smelling like grease or mineral spirits. Leave the pan outside, and the dog will be glad to clean it up. Works for me. Quote Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32783 Share on other sites More sharing options...
Rob Posted March 29, 2009 Share Posted March 29, 2009 It works very well on lawn mower carb's also, Just a suggestion, but if you boil the hot dogs first you won't have to change the water. And as an added benefit, you can also clean and lubricate the parts at the same time. If you save the water to wash your hands afterward they will smell like hot dogs and she won't complain about you coming in the house smelling like grease or mineral spirits. Leave the pan outside, and the dog will be glad to clean it up. Works for me.Hi James, you bring up some very valid points. I wonder how the leftover water would work on my foot stench and fungus growth? That would really get rid of the complaints if successful.The dog sleeps with us at night. If we could just get it to quit raiding the next door restaurants dumpster, we would both be happy. He doesn't go hungry so don't know how appealing the water would be to him.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/8822-problem-with-12-spd/#findComment-32785 Share on other sites More sharing options...
HK Trucking Posted March 29, 2009 Share Posted March 29, 2009 Hi James, you bring up some very valid points. I wonder how the leftover water would work on my foot stench and fungus growth? That would really get rid of the complaints if successful.The dog sleeps with us at night. If we could just get it to quit raiding the next door restaurants dumpster, we would both be happy. He doesn't go hungry so don't know how appealing the water would be to him.RobRob!!!! Use extreme caution here!!!!!!!!!If you use the hotdog water to treat your foot problems, and then allow the dog to sleep with you, you might just wake up as an "amputee"!!!!!! Quote "If You Can't Shift It Smoothly, You Shouldn't Be Driving It" Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32787 Share on other sites More sharing options...
Rob Posted March 29, 2009 Share Posted March 29, 2009 Rob!!!! Use extreme caution here!!!!!!!!!If you use the hotdog water to treat your foot problems, and then allow the dog to sleep with you, you might just wake up as an "amputee"!!!!!! You have a point well tanken!! Maybe I should not try to keep the dog out of the dumpster!!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/8822-problem-with-12-spd/#findComment-32788 Share on other sites More sharing options...
other dog Posted March 29, 2009 Share Posted March 29, 2009 Little cooking tip here- you can also save that water and freeze it after you boil the parts and hot dogs, and you'll have an excellent stock to make soups and stews with.Wow, next door to a restaurant-with a dumpster outside! How lucky can you be? Reminds me of my first driving job. Drove a garbage truck- paid $2.75 an hour, plus all I could eat. Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32791 Share on other sites More sharing options...
other dog Posted March 29, 2009 Share Posted March 29, 2009 PAI's complete "selectair" valve is not out of line on price as I think mine was about $60.00. I did not use it as I actually "boiled" mine in hot water, (yes, on the stove) to clean the accumulated garbage/buildup from it. It works as new now. Mine had probably never had the air filter changed in it's lifetime, (exaggeration).My shift cylinder kept leaking internally around the hi/low piston internal to the transmission. I found it by removing only one top cover bolt and it was like a tornado through a keyhole from the air escaping. I then removed the shift cover, tore it completely down again, boiled it, (same way on the stove), then honed the cylinder with a small cylinder hone and boiled it again. It was then put back together without any problems, (so far). I guess now you can see why "Momma" gets so angry with me. At least I changed the water before boiling the hot dogs in the same pan.Robso THAT'S where i've been going wrong-i've been boiling my parts in cold water! that's a good one right there...anyway, women get bent out of shape over the littlest things. Reminds me of the time Jo got pissed off just because I used the good dish towel to wipe my stew pot down after i'd just reseasoned it with Crisco Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32793 Share on other sites More sharing options...
Rob Posted March 29, 2009 Share Posted March 29, 2009 so THAT'S where i've been going wrong-i've been boiling my parts in cold water! that's a good one right there...anyway, women get bent out of shape over the littlest things. Reminds me of the time Jo got pissed off just because I used the good dish towel to wipe my stew pot down after i'd just reseasoned it with Crisco Crisco is good sprinkled with cimmamon by the tablespoon. Sorta like eating seasoned oysters. Constipation is a thing of the past and never troubles me further.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/8822-problem-with-12-spd/#findComment-32797 Share on other sites More sharing options...
MACKTRUCKS4 Posted April 1, 2009 Author Share Posted April 1, 2009 You guys are no help but you sure are entertaining. I got the problem fixed (with a 20 lb. sledge) no really, I took the top housing off yesterday for one last time and after some closer examining I discovered that someone installed the wrong o-ring on the hi-lo piston which was letting air by-pass it enough to cause my head to ache. I got all the new parts last fall and let someone else put it together so I would have something to do in the winter time (fixing it again). It's a good thing I procrastinate because I did not clean off my bench for all the old parts were still on the bench to compare. Lo and behold the two o-rings were not the same, one was thinner which made for a not so good seal. I can put this one to bed. Quote Live every day like it's your last, because one of these days, it will be. Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-32966 Share on other sites More sharing options...
Rob Posted April 2, 2009 Share Posted April 2, 2009 You guys are no help but you sure are entertaining. I got the problem fixed (with a 20 lb. sledge) no really, I took the top housing off yesterday for one last time and after some closer examining I discovered that someone installed the wrong o-ring on the hi-lo piston which was letting air by-pass it enough to cause my head to ache. I got all the new parts last fall and let someone else put it together so I would have something to do in the winter time (fixing it again). It's a good thing I procrastinate because I did not clean off my bench for all the old parts were still on the bench to compare. Lo and behold the two o-rings were not the same, one was thinner which made for a not so good seal. I can put this one to bed. Hi there, that is what I was trying to relay. The air was escaping around the "O" rings on that piston. It is a common area to give problems. I've seen several rings scored or cut upon installation or inadequate lubrication by experienced mechanics. Unfortunately, it happens to the best of us. I proved mine leaking in that are by removing the top cover, inverting it on a bench with 60 psi of air pressure applied, and feeling the escaping rush of compressed air. A new ring kit from Mack and all is good.Glad to hear you got it repaired again. It should serve you well for a long time.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/8822-problem-with-12-spd/#findComment-32969 Share on other sites More sharing options...
MACKTRUCKS4 Posted April 17, 2009 Author Share Posted April 17, 2009 Ok, now that I got the air problem fixed, now the trans seems to shift very sluggish between hi and lo. Could it be to much lube in the cylinders, and restricting the air flow? Possible slowing down the shifting? Quote Live every day like it's your last, because one of these days, it will be. Link to comment https://www.bigmacktrucks.com/topic/8822-problem-with-12-spd/#findComment-33953 Share on other sites More sharing options...
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