The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Ok i will start disconnecting thd maxi lines but will have to keep truck running i suppose to see which ones leaking. I still dont understand how the air leak stops when i turn engine off. Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501214 Share on other sites More sharing options...
Joey Mack Posted June 25, 2022 Share Posted June 25, 2022 I am at a bit of a loss.. i dont know how , truck off or on has an effect, unless there is an electric over air switch.. Im sorry, it is also 9:30 PM here and I need to hit the sack.. I will check back tomorrow... jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501215 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Heres a picture of a spring brake thats on truck Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501216 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Now the damn leak is stopped. Its intermittent. Tried pumping brakes and park brake and dumping air tank and I cant get it to leak. But it will wait till another time then leak again. Guess I just need to try wait till its leaking then undo the hoses and see. while its leaking I see all the brakes try come on for a couple seconds and while the brake rods are jumping in and out a bit that flap valve has aic coming out the bottom then it just stops leaking and brakes return to off. no luck today for a fix as I cant hone in on the problem unless its leaking Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501218 Share on other sites More sharing options...
Swishy Posted June 25, 2022 Share Posted June 25, 2022 Yup do what Genn sez disconect one by one hose a leaking 'O' ring between the spring brake chambers will send a bit of air to all spring brakes and also the valve where the air is delivered from splash sum soapy water allover the culprits cya Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501222 Share on other sites More sharing options...
MACKS Posted June 25, 2022 Share Posted June 25, 2022 Swap them all out and be done with it.. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501229 Share on other sites More sharing options...
Joey Mack Posted June 25, 2022 Share Posted June 25, 2022 replacing all the brake chambers is a good idea, maybe as you do it, perform the test that Glenn suggested, so that if you find the issue, you get the answer to the mystery, and the brakes have all new cans of equal quality.. good luck, Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501236 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 I opened the box with new cans in it and the rods are a mile too long. Even if i screw the eye all the way down to end of thread it would still be too long. See on my can pic above the rod barely sticks out of can before the eye and the eye is welded to rod with no threading visible its just plain rod. The new cans rods are threaded to within say 3 inches or so of cans. Will have to take them back and see if they can get shorter ones with welded on eye or threads that go all the way to can and cut excess off. Dang it. Thanks for the help. Will post back when i find the problem Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501243 Share on other sites More sharing options...
Onyx610 Posted June 25, 2022 Share Posted June 25, 2022 You need to cage it and cut it to length. There is nothing wrong with them. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501245 Share on other sites More sharing options...
mrgumby Posted June 25, 2022 Share Posted June 25, 2022 Wait. Don’t return them yet. They are that long to fit different vehicles. You need to measure your old cans asumming they were cut correctly and cut the new ones to that length. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501246 Share on other sites More sharing options...
MACKS Posted June 25, 2022 Share Posted June 25, 2022 1 hour ago, Onyx610 said: You need to cage it and cut it to length. There is nothing wrong with them. Why cage them,I just cut them? 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501249 Share on other sites More sharing options...
MACKS Posted June 25, 2022 Share Posted June 25, 2022 2 minutes ago, MACKS said: Why cage them,I just cut them? Looking at your picture I’ve never seen them cut that short,ther is a correct way to set them up,that doesn’t look right to me.. Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501250 Share on other sites More sharing options...
MACKS Posted June 25, 2022 Share Posted June 25, 2022 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501252 Share on other sites More sharing options...
Mark T Posted June 25, 2022 Share Posted June 25, 2022 (edited) They need to be caged to cut to the correct length, or the brakes'll never work. Are you sure there's not some issue with traction control or something ? Seems odd it comes and goes with the key. (if it even has traction control ?) one thing for sure it's not a common set up for a 2004. Maybe some pictures of the whole back of it from behind and looking down from in front of the drive axles ??? Edited June 25, 2022 by Mark T more information 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501272 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 The truck has meritor axles all round but have mack stamped on the tags on diffs. the drive axles are 160 series meritor running dx225 disk brakes and the cans are located on the front side of axles. Here is a picture with brakes released. Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501279 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Heres a pic with brakes on. The truck mechanic said he adjusted them a couple months ago when he inspected it for rego saying they arent allowed to go past 90 degrees on lever brakes applied. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501280 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Here is new 2024 cans. See how the thread doesnt allow the rod to become as short as the brakes on truck. I would have to cut the shaft right near can and weld the old eye on with only the weld holding and no threads. This makes me nervous. Im hoping to get shorter cans that look same from factory without me welding. They are MGM brand on truck Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501281 Share on other sites More sharing options...
Joey Mack Posted June 25, 2022 Share Posted June 25, 2022 the last pic, with brakes 'on' is the measurement you need to duplicate..it looks like pre-made brake chambers, with welded yokes.. he is right about not going passed 90 degree's.. my guess is the new maxis you have dont have threads all the way down to the service side housing?? Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501282 Share on other sites More sharing options...
Joey Mack Posted June 25, 2022 Share Posted June 25, 2022 Wrong maxi's.. those are for drum brakes... Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501284 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Front drive diff tag: Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501285 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Theres 2006 on tag on one diff so i think someone has maybe replaced diffs from drums and springs to airbags and discs at some point but i dont know what truck the diffs came from Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501286 Share on other sites More sharing options...
Joey Mack Posted June 25, 2022 Share Posted June 25, 2022 if you have a good Mack parts guy, he can tell you what it was built with... when major components are replaced, like the engine, tranny, and rears for example,, you need to use the serial number of the part and not the v.i.n.,,, just sayin'...jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501287 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 Old owner said that a previous haulage company that bought the truck new was pulling 2 trailers behind it and put a new motor in it around 2007 (different year engine i suspect due to weird wiring in behind dash along with the dash cluster from donor truck i suspect as theres abs light in dash but no abs i can see on truck) its got the ea7470 motor with no polution gear or exhaust recirculation that i can see and has the powerleash brake i think as theres no spacer between tappet cover and heads. its a grain tipper with sleeper cab. Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501288 Share on other sites More sharing options...
The Nitro Posted June 25, 2022 Author Share Posted June 25, 2022 The mack dealers have no idea whats in it as their build sheet shows drum brakes all round and spring suspension. I had to ring meritor to find out what brake pads to suit as mack dealer send me drum brake shoes according to records with vin number. Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501289 Share on other sites More sharing options...
Joey Mack Posted June 25, 2022 Share Posted June 25, 2022 sir,, with respect, I have to bow-out.. seems to me you have a home made truck, and the only way to get parts is like I said, with the component serial numbers.. and I am sure you will always have to remove the bad parts and take them with you, to the parts store.. I pray that you have NON-Mack parts store's that know what they are doing.. I suggest you record all of the data of of any data plate you find, ie: tranny/ engine/ rears/ axle housing's/ front axle beam/ steering box/ the v.i.n. on the frame rail/ the v.i.n. on the cab shell/ etc... this effort will help you later on.. God Bless you sir.. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69911-air-leaking-out-of-bottom-of-this-thing/page/2/#findComment-501290 Share on other sites More sharing options...
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