dds92780 Posted November 10, 2012 Share Posted November 10, 2012 So i just got all 4 drums and shoes and bushing and s cams done on my tractor last week. Well today it just started making a vibrating loud humming sound when braking but not applying fully. And its more pronounced when empty. What can cause this? I adjusted the slack adjusters to spec again and still when braking the loud hummimng vibrating is coming from somewhere. My thoughts are that the shoe isnt touching fully? im so sick of this truck at this point with all the repairs i do Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/ Share on other sites More sharing options...
theakerstwo Posted November 10, 2012 Share Posted November 10, 2012 Start were you left off and start pulling drums and you will find it. Which one? i dont know but sounds like the first one to me. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-145247 Share on other sites More sharing options...
Mike Posted November 24, 2012 Share Posted November 24, 2012 Start were you left off and start pulling drums and you will find it. Which one? i dont know but sounds like the first one to me.Glenn, I was looking forward to hearing back from this person and hearing some good results. Do you wonder if one or more drums had a ridge and could not adjust enough?Hope we hear from him or her soon.mike Quote Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-147922 Share on other sites More sharing options...
other dog Posted November 24, 2012 Share Posted November 24, 2012 adjusted too loose maybe? I always lock manual adjustors down then back off a quarter turn. I've known some drivers that only backed them off one "click". Quote Producer of poorly photo-chopped pictures since 1999. Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-147927 Share on other sites More sharing options...
David Posted November 25, 2012 Share Posted November 25, 2012 Adjust the brakes correctly on one axle and back them way off on the other. See if the noise is still there. Then do the opposite axle correctly and back the other one way off. This will at least tell you which axle is the problem. Then you can do it again only side to side and narrow it down to one drum. Quote Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-147961 Share on other sites More sharing options...
theakerstwo Posted November 25, 2012 Share Posted November 25, 2012 Glenn, I was looking forward to hearing back from this person and hearing some good results. Do you wonder if one or more drums had a ridge and could not adjust enough?Hope we hear from him or her soon.mike Yes and i may have run him off with the help i give to him. Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-148019 Share on other sites More sharing options...
dds92780 Posted November 29, 2012 Author Share Posted November 29, 2012 Well, here are some results. I am taking it into the shop tomorrow to have them attempt to fix it. All my brakes show anywhere from 100 to 140 degrees temperature. I have a heat gun and the culprit seems to be the passenger rear axle heating up to 330 degrees even in this cold weather. yeah thats a problem. only thing i can see is that the brake chamber from the chamber to the center of the pin has 4 inches of clearance and the others have 2 inches. this could be causing it. im not sure what it is. but every brake being close to 120 to 150 degrees shows that the right rear is doing all the work and thats where the sound could be coming from??? where would you guys start? Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-148524 Share on other sites More sharing options...
dds92780 Posted November 29, 2012 Author Share Posted November 29, 2012 here are my guesses and this is without having hardly any mechanical knowledge at all about this . Probably gonna be a brake chamber and something on it needs to be shortened, maybe a new slack adjuster? Its funny because the vibration goes away when you push the brakes down a lil harder. this has to be because the right rear is doing most of the work, so when i push down more the others start to do work. yep im a genius Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-148528 Share on other sites More sharing options...
rsb502 Posted November 29, 2012 Share Posted November 29, 2012 All the brake chamber push rods have to be the same length and the same slack adjuster and the same adjustment to apply the same braking effort, if you have one chamber that has been replaced and the push rod was cut too long it will not have the same geometry as the other brakes and either apply more or less effort depending on the slack adjuster angle. To properly size the push rods and adjust the slack adjusters, get the correct slack adjuster template for your slacks and adjust the slack to spec with the chamber removed then measure the distance from the mounting plate to the adjuster pin and cut the push rod to the correct size. I would guess you just need to trim that one to match the others or if the chamber is not retracting fully and thus building excess heat . 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/28258-what-heck-is-wrong/#findComment-148531 Share on other sites More sharing options...
rsb502 Posted November 29, 2012 Share Posted November 29, 2012 Oops.....building excess heat because its not fully retracting when the brakes are released replace the offending chamber, when the lines are removed make sure the air pressure applied to the chamber to release the brakes is not restricted at the quick release valve. Well I think that's it, I am just guessing so you know you should probably ask a professional. 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/28258-what-heck-is-wrong/#findComment-148534 Share on other sites More sharing options...
dds92780 Posted November 29, 2012 Author Share Posted November 29, 2012 awesome answer superdog! now if i could just copy and paste that to my mechanic so they dont charge me time for diagnosing the problem and taking longer than they should. i will post results though Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-148538 Share on other sites More sharing options...
thomastractorsvc Posted November 29, 2012 Share Posted November 29, 2012 who did the brake work the first time around and did they replace any brake chambers and slack adjusters? Have you caged that brake and see if the others are working? Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-148540 Share on other sites More sharing options...
dds92780 Posted November 30, 2012 Author Share Posted November 30, 2012 I just got it back but it was late at night and i dont know what they really did yet. The secretary told me that they had to shorten rods and change 3 brake chambers though so i will bring my heat gun tomorrow and see what happens Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-148685 Share on other sites More sharing options...
dds92780 Posted December 6, 2012 Author Share Posted December 6, 2012 Well, here is an update and im still pretty confused. UP to this point my brakes still had a vibration sound when braking so we took off one of the wheels and noticed the wheel bearing was slightly too tight so i can honestly say that it doesnt do that sound anymore. All the brake chambers up to this point have the correct geometry and the s cams and slack adjusters are new as well. Here is the problem still though. I have a heat gun , so i test the heat of each drum on the tractor and im stumped as to why this is happening and so is my mechanic and my dad who is very smart about mechanics too! The problem is that the heat for all 4 drums is significantly different.LEFT FRONT 125 degreesLEFT REAR 225 degreesRIGHT FRONT 170 degreesRIGHT REAR 315 degrees!!!I don't get it because everything is new. My dad things that i just got harder shoes on the one that is getting to 300 degrees but what i dont understand is why i cant just get them to all work the same and do 150 each lets say!PLEASE HELP cause i dont know what to do other than just drive it and not care anymore. thanks Quote Slow and Steady Wins the Race! Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-149632 Share on other sites More sharing options...
Lmackattack Posted December 6, 2012 Share Posted December 6, 2012 It may help if you put heat stickers on the drums. They do this with race cars to see if they are all reaching the correct temp. You will not get a good reading if you have to stop,Jump out and take a reading off the drums. The temps will drop fairly quick in the cold....Its more important that they all reach say 300 deg under a normal loaded stop. If 3 corners hit 300 but one corner is 600 then you know one is grabbing harder. Also test when the truck is loaded, limited wind and warm weather. This will give you more accurate readings. Quote Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-149636 Share on other sites More sharing options...
thomastractorsvc Posted December 6, 2012 Share Posted December 6, 2012 Does the hub get as hot or does it get hotter then the drum? If the hub is geting hotter than the drum readjust the bearings.I would pull that drum and check that the brakes and s-cam go back to a neutral postion when bakes are released and they dont hang somewhere. I would recheck the drum and for thickness or out of round and same with the shoes. If thats the only hub/drum that is causeing problems it is more than likely the cause, the second would be the making sure that air evacs from the brake chamber the same as the others, this delay could cause the extended drag. Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-149698 Share on other sites More sharing options...
rsb502 Posted December 9, 2012 Share Posted December 9, 2012 I think I put in one of my other posts to check the quick release valves right? Im too lazy to go back and look, check the QR valves to make sure your brakes arent hanging and check to make sure the application pressure reaches all the chambers(take the service lines off the brake chambers and make sure there is equal air flow to all the chambers. I have actually seen a line that was pinched in a frame behind another piece that was replaced that caused one brake to act a fool. I think other than that the hub bearings are the next big thing have you checked the torque on all the hub nuts to ensure they are equal? spun them in the air by hand to make sure none of them are tighter than the others? 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/28258-what-heck-is-wrong/#findComment-150309 Share on other sites More sharing options...
Vladislav Posted December 13, 2012 Share Posted December 13, 2012 Adjust the brakes correctly on one axle and back them way off on the other. See if the noise is still there. Then do the opposite axle correctly and back the other one way off. This will at least tell you which axle is the problem. Then you can do it again only side to side and narrow it down to one drum.Make better this way. If no results you will continue with bearings. Don't mix the sources of the issue up. Divide them and follow step-by-step. Quote Никогда не бывает слишком много грузовиков! leversole 11.2012 Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-150984 Share on other sites More sharing options...
Jjj Posted March 13, 2021 Share Posted March 13, 2021 Any fix on the brake vibration? Im having a similar problem and noone has a clue. Loud vibration-humming noise when Appling the breaks, only every other application but seems to get more frequent as days pass. Quote Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-470568 Share on other sites More sharing options...
Joey Mack Posted March 13, 2021 Share Posted March 13, 2021 check for loose rivets in the linings... Quote Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-470575 Share on other sites More sharing options...
theakerstwo Posted March 13, 2021 Share Posted March 13, 2021 I had a crack drum making a noise a few months ago. 1 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/28258-what-heck-is-wrong/#findComment-470590 Share on other sites More sharing options...
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