Mark T Posted March 23, 2023 Share Posted March 23, 2023 47 minutes ago, MACK321 said: Mark T chamber is brand new put it in 2 weeks ago Was that by any chance when all this started ? Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527710 Share on other sites More sharing options...
MACK321 Posted March 23, 2023 Author Share Posted March 23, 2023 2 minutes ago, Mark T said: Was that by any chance when all this started ? No my mechanic said it might be it and replaced it Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527711 Share on other sites More sharing options...
MACK321 Posted March 23, 2023 Author Share Posted March 23, 2023 6 minutes ago, Joey Mack said: I know,,, I'm sorry.. at this point, I guess we will just pray that someone figures out your issue.. It's hard to do this one from 1200 miles away.. thank you Joey your the man thanks for all your help and the other guys too for taking the time and trying to help me out I will give you guys in update once I find the problem 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527712 Share on other sites More sharing options...
mechohaulic Posted March 23, 2023 Share Posted March 23, 2023 I didn't think the two pin slack/ clevis arrangement was still used. is that the style having a direction arrow ?? don't remember .. I see one rubber hose going to the can, plastic coming out other size. did anyone disconnect the service lines at the can side and install gauges to watch pressures?? agree with latest comments discussing push rod angle ; there's a situation . Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527713 Share on other sites More sharing options...
fjh Posted March 23, 2023 Share Posted March 23, 2023 So was There any work done just prior to the start of this situation A brake job? The ware on the push rod indicates that the( Brake can )may be mounted a little off in the mount in my mind! I notice the brake is close to needing adjusted! I HATE them gunite slacks! That said its over 90 cause it needs adjusting in my mind that is not the issue here just me! The slack should be keeping up on the set! my observation its not! How ever If the shoes were change and they used Recon shoe I have seen the cut outs where the roller sits worn so bad they tend to roll up the ramp so to speak on the cam side and cause the brake to lock up! I also ,when we were using this recon junk I would inspect the shoes I was handed And Reject them if I didn't like what I saw I told them I would mount this shit on a customer truck! I'm not saying this is the case here just stating an experience I have Even seen some new shoes the cam side roller cut out is NOT cut deep enough and can do the roll up thing after a short while of operation! you need to pay attention to what you are handed! I always look for at least 1/3 depth of the roll seat! just an observation! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527728 Share on other sites More sharing options...
Joey Mack Posted March 23, 2023 Share Posted March 23, 2023 FJH.. you got me thinking.. doesn't 4515 Q, shoes an 4707 Q Plus, use different hardware? Maybe they got shoes in one box and the wrong hardware in the other box.. Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527731 Share on other sites More sharing options...
fjh Posted March 23, 2023 Share Posted March 23, 2023 Possible Joe !Original post states new brakes ! Did this problem start at that point???? That slack in my mind is not keeping up on the adjustment That said ! I'll bet the original slacks were Meritor with the button on them! The adjustment pin setting on the style of pushrod that is shown there is for the Meritor style NOT Gunite ! Two different clevises! hence not adjusting properly! you can't mix auto slack styles with the welded clevis! The button style should always be used! 2 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527740 Share on other sites More sharing options...
Mark T Posted March 23, 2023 Share Posted March 23, 2023 Didn't Macks usually come with Haldex on them in that era ? Gunites are junk...but usually work until they're backed off at least. I don't have much faith in any form of gold brake chamber either. There's differences in those two pin clevises too. Is that miss matched ? Also wondering about the suspension. Is the bushing wiped out in the spring eye ? Does the truck have aluminum hubs ? if so, are they rotted ? SO hard to figure from texts and not looking right at it. Just a side note on the Gunites. It's worth loosening the air chamber from the mounting pad so as to back off brake adjustment, then after removing drum turn the adjustment on the Gunite slack in the adjust direction to get it back to where it needs to be with new shoes and drums. At least they still work if you only adjust and not back off it seems like to me anyway. (lol) some nice Gunites, some cheap gold air chambers and those new RSD shoes, makes for one fine stopping truck 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527759 Share on other sites More sharing options...
mrsmackpaul Posted March 23, 2023 Share Posted March 23, 2023 MACK 321 you really need to disassemble the whole shooting match and go thru it from front to back If you dont know were everything is at you need to start at the start so you actually know all is okay with each component that makes up the braking system other wise your just guessing like us what is right and wrong And am I'm trying my hardest to not come across as rude and been a smart ass, I am genuinely trying to help and explain what I would do Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527761 Share on other sites More sharing options...
MACK321 Posted March 24, 2023 Author Share Posted March 24, 2023 (edited) Yeah I understand it's at a shop getting looked at Edited March 24, 2023 by MACK321 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527837 Share on other sites More sharing options...
mechohaulic Posted March 25, 2023 Share Posted March 25, 2023 On 3/23/2023 at 10:15 AM, Joey Mack said: FJH.. you got me thinking.. doesn't 4515 Q, shoes an 4707 Q Plus, use different hardware? Maybe they got shoes in one box and the wrong hardware in the other box.. never had that problem either when the hardware came in same box as shoes. every where you look things are being broke down more and more. one day if you go to get something to eat , the fork and knife will cost extra. I don't buy anything without opening a box to inspect item that is suppose to be inside. Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527873 Share on other sites More sharing options...
Joey Mack Posted March 25, 2023 Share Posted March 25, 2023 So true Mech.. even at the end of my business last July, I was still expecting the BOX to have the same CONTENTS as it always had, only to find out,,,, nope.. and stupid stuff like seals, and gaskets... MackVo,,, or should I say,,, VoMack?? is notorious for this.. I have been impressed by after market re-build kits more than OEM kits.. (PAI/ and Maxiforce for the John Deere engines I built) Yes to opening the box to take inventory... Jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-527875 Share on other sites More sharing options...
Joey Mack Posted March 30, 2023 Share Posted March 30, 2023 Do you have any good news to post about the rear brakes? Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528164 Share on other sites More sharing options...
mechohaulic Posted March 31, 2023 Share Posted March 31, 2023 been at the "shop" for almost a week ; for his sake hope it's not a guessing game changing parts till it works .$$$$$$ Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528216 Share on other sites More sharing options...
Joey Mack Posted March 31, 2023 Share Posted March 31, 2023 I bet it is,,, Mech.... 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528217 Share on other sites More sharing options...
Joey Mack Posted March 31, 2023 Share Posted March 31, 2023 With respect... I believe the 'poster' is not doing the work. He is relying on a mechanic. I believe the mechanic has a parts cannon in the shop and fires it regularly.. I really try to avoid criticizing mechanics, but, post's like this one cause me to post this dribble.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528221 Share on other sites More sharing options...
mechohaulic Posted March 31, 2023 Share Posted March 31, 2023 it's not always the mechanic if he's working at a big time dealer shop. sad side is like the medical field pushes pills; the Maintenace area seems to be pushing parts. so different from yrs back (for the most part). Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528223 Share on other sites More sharing options...
JoeH Posted March 31, 2023 Share Posted March 31, 2023 What's the history of this truck? Have you owned it long? Did you buy it with this problem? Did the problem start after having the brakes replaced? Joey may be on to something with that frame twist. Looking at it, it would appear the frame is twisted in such a way to apply the least weight to the passenger rear wheels. Typically trucks have ABS on the steer and the front drive axles, not on the rear drive axle. So your ABS would of course do nothing in this situation. Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528233 Share on other sites More sharing options...
Joey Mack Posted March 31, 2023 Share Posted March 31, 2023 Yes mech. You have a point. It's another reason I left the dealership world.. I used to get in trouble for question why my boss rolled the cannon up to my truck and and said install a new, sucn and such.. when an hour or 2 more diagnostics may find the problem. Then the truck could be fixed, and the shop learns something as a group.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528235 Share on other sites More sharing options...
fjh Posted March 31, 2023 Share Posted March 31, 2023 1 hour ago, Joey Mack said: Yes mech. You have a point. It's another reason I left the dealership world.. I used to get in trouble for question why my boss rolled the cannon up to my truck and and said install a new, such and such.. when an hour or 2 more diagnostics may find the problem. Then the truck could be fixed, and the shop learns something as a group.. Agree totally ! we had a 3406 come in pushing coolant! the guys were going to throw a compressor at it cause it looked like it was over heated the paint was dark colored! I had just come to work was about to start my day and I over heard the conversation of why it was in the shop. I expressed my concern that if it looked overheated then maybe you should check the coolant lines in and out of the compressor! Response was Oh That's likely a good Idea hadn't thought of that!!! and sure enough! they learned something !! Had I not mentioned that we would have ended up eating a compressor job cause they wouldn't have checked the why portion of the job ! you also end up with a Pissed off customer that may or may not come back ! You can't attack a job like this with Blinders on ! Tunnel vision and parts Canons are not suitable in a diagnostic situation! Its A LAST resort ! I personally like to have customers that swear by me not AT ME! 😅 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528239 Share on other sites More sharing options...
Solution MACK321 Posted March 31, 2023 Author Solution Share Posted March 31, 2023 Just picked up the truck today it was a wheel speed sensor 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528242 Share on other sites More sharing options...
67RModel Posted March 31, 2023 Share Posted March 31, 2023 Dang!......A lot of bullshittery for probably an $80 part. Was there a code or did the parts cannon inevitably find the culprit? Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528243 Share on other sites More sharing options...
Joey Mack Posted March 31, 2023 Share Posted March 31, 2023 🤔 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528245 Share on other sites More sharing options...
MACK321 Posted March 31, 2023 Author Share Posted March 31, 2023 It was the passenger front axle no code I drove it bobtail home and didn't lock 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528246 Share on other sites More sharing options...
Mark T Posted March 31, 2023 Share Posted March 31, 2023 Thanks for posting the cure. Not everyone does that. Glad you're fixed. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/72584-rear-passenger-axle-locking-when-braking/page/4/#findComment-528248 Share on other sites More sharing options...
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