Old Man Posted March 11, 2023 Share Posted March 11, 2023 9 Speed T2090 replaced gear shift knob with new one with range selector, new O rings in range selector cylinder on top of transmission, no air leaking by when line is removed. What's next, slave cylinder? Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/ Share on other sites More sharing options...
Joey Mack Posted March 11, 2023 Share Posted March 11, 2023 the air cylinder at the top of the rear case will cause this air leak. you can check it by removing one of the lines to see if air is by-passing.. Replacing the orings and gasket is easy. you do have to remove the top cover on the rear case in order to remove the yoke bolt, then the whole unit pulls out of the rear case, and you can re-ring it on the bench.. it is reccomended to replace the yoke bolt, of course you can put some patch lock on it and put it back if the end of it is not deformed.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527067 Share on other sites More sharing options...
Old Man Posted March 12, 2023 Author Share Posted March 12, 2023 I removed the small plate with cylinder underneath with shifting fork . Replaced all 6 o rings with new. Started truck, built up pressure, still leaking at shift knob. Pulled airline off top with system full charged no leaking by new o rings. Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527079 Share on other sites More sharing options...
Joey Mack Posted March 12, 2023 Share Posted March 12, 2023 (edited) seems odd, I assume you hooked the spaghetti lines up to the knob correctly? when you replaced the shuttle valve, did you inspect the little plunger for wear? I forgot to ask... will it range shift? Damn, I'm getting rusty.... I need to hit the books.. Edited March 12, 2023 by Joey Mack more content needed 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527080 Share on other sites More sharing options...
Old Man Posted March 12, 2023 Author Share Posted March 12, 2023 This is the new that replaced the old, both look exactly the same. I switched one line at time with both knobs side by side. Air leaking out of round dark hole at the bottom of the image. The range selector works just fine and is audible. Thanks for your help. Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527081 Share on other sites More sharing options...
Joey Mack Posted March 12, 2023 Share Posted March 12, 2023 did the original shift knob have a blue range button? That is a 2070 shift knob in the picture. I forget if there is a different knob for the 2090.. I will go to my book tomorrow morning and try to find the trouble shooting guide.. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527082 Share on other sites More sharing options...
Old Man Posted March 12, 2023 Author Share Posted March 12, 2023 I have already thrown the old one away, can't remember the color for sure but the reason I purchased a new knob is because it's was doing what it's doing now and thought it might have been my problem. I've owned the truck for about 10 years and this problem has just popped up. Again thank you. Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527091 Share on other sites More sharing options...
Joey Mack Posted March 12, 2023 Share Posted March 12, 2023 I seem to be at a loss, outside of a bad oring or swapped lines. Im going to get the book and see if there is a plumbing picture that I can post for you.. Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527092 Share on other sites More sharing options...
Popular Post MACKS Posted March 12, 2023 Popular Post Share Posted March 12, 2023 Different trans but I had the same problem with my 12 speed and it was the shift cylinder on top of the tranny that was causing it,new o rings fixed the problem.. 3 Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527093 Share on other sites More sharing options...
Joey Mack Posted March 12, 2023 Share Posted March 12, 2023 I hope these pictures help you.. I clearly forgot that tranny has an internal range cylinder.. I was thinking about some 300 series tranny's. Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527094 Share on other sites More sharing options...
Old Man Posted March 12, 2023 Author Share Posted March 12, 2023 Thank you, thank you, thank you, these are the diagrams I've been looking for. I'll double check the spaghetti line placement in diagram 1 tomorrow. I installed all new o rings in diagram 3, purchased them as a kit. Diagram 2 & 4 looking for a rebuild kit, just haven't come across it yet. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527122 Share on other sites More sharing options...
Joey Mack Posted March 12, 2023 Share Posted March 12, 2023 Sweet... I am glad that I was able to help you, sorry about the incorrect info about range cylinder location.. Its been a few years since I worked on a 200 series.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527125 Share on other sites More sharing options...
MACKS Posted March 12, 2023 Share Posted March 12, 2023 47 minutes ago, Old Man said: Thank you, thank you, thank you, these are the diagrams I've been looking for. I'll double check the spaghetti line placement in diagram 1 tomorrow. I installed all new o rings in diagram 3, purchased them as a kit. Diagram 2 & 4 looking for a rebuild kit, just haven't come across it yet. Thanks Easy to find online,just google it..good luck. Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527128 Share on other sites More sharing options...
Solution Joey Mack Posted March 12, 2023 Solution Share Posted March 12, 2023 Hopefully, OldMan, your next post will be the one that says its fixed.. 👍 jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-527138 Share on other sites More sharing options...
Joey Mack Posted April 13, 2023 Share Posted April 13, 2023 That is great news.. can you post the solution for others to see, in case someone comes along with the same issue? Awesome...... Quote Link to comment https://www.bigmacktrucks.com/topic/72598-air-leaking-out-of-gear-shift-knob-99-ch613/#findComment-529129 Share on other sites More sharing options...
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