hdfx81 Posted December 3, 2016 Share Posted December 3, 2016 What's involved to update my slack adjusters to self adjusting on my 87 superliner with Rockwell rears? Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/ Share on other sites More sharing options...
Underdog Posted December 3, 2016 Share Posted December 3, 2016 You can install automatic slack adjusters in place of your original slack adjusters. Any that you purchase will come with instructions for installing and initial setup. Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-353873 Share on other sites More sharing options...
topo Posted December 4, 2016 Share Posted December 4, 2016 The push rod coming out of the brake chamber may need be longer then the one in use now . Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-353875 Share on other sites More sharing options...
Underdog Posted December 4, 2016 Share Posted December 4, 2016 Get the right size slacks and the pushrod length should not change. The operating angle must be maintained. Some adjusters will have a new style clevis included in the kit. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-353892 Share on other sites More sharing options...
davehummell Posted December 4, 2016 Share Posted December 4, 2016 When you install them don't forget them, If you got slop in your cam bearings they will not work as good as you wish they would. grease them often and keep the cams greased. I had to keep after them on rolloffs and frontloaders.When city driving I found I still had to adjust them. The other place I worked had long haul rigs and I didn't have to adjust them as much. The kit should have a gauge in it read the instructions and you should be good to go. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-353900 Share on other sites More sharing options...
hdfx81 Posted December 4, 2016 Author Share Posted December 4, 2016 Thanks for all the info guys. Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-353993 Share on other sites More sharing options...
gearhead204 Posted December 6, 2016 Share Posted December 6, 2016 all I will say is keep a close eye on them! i have changed out more auto slacks than manual ones due to failure to stay adjusted, I have a good fight with a old school friend who is a state trooper over auto vs. manual. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354110 Share on other sites More sharing options...
Underdog Posted December 6, 2016 Share Posted December 6, 2016 all I will say is keep a close eye on them! i have changed out more auto slacks than manual ones due to failure to stay adjusted, I have a good fight with a old school friend who is a state trooper over auto vs. manual. One big mistake a lot of mechanics and owners make is to regularly adjust auto slacks. Set them and forget them! Manually adjusting wears out the ratchet mechanism, causing premature failure. The only time to move them manually is backing off and re-adjusting during a brake reline. Gearhead I agree, on my own truck I prefer manual slacks, you are underneath greasing every couple weeks anyway, just take a wrench with you to hit the brake adjustment. Seems to me newer than 1996 requires automatic slack adjusters. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354118 Share on other sites More sharing options...
HeavyGunner Posted December 6, 2016 Share Posted December 6, 2016 On December 3, 2016 at 8:38 PM, davehummell said: When city driving I found I still had to adjust them. The other place I worked had long haul rigs and I didn't have to adjust them as much. Far from an expert am I but I've had exactly the opposite experience with auto adjusters here in MT. With the flat terrain and virtually no stop lights in my daily 330 mile round trip I rarely step on the brakes except to take the cruise off or lightly breaking down hills to help the jake. From what I can tell I don't put enough applied air pressure to the brakes which actuates the adjuster. I believe it takes 60 psi for them to actually adjust at all. To remedy this every night the last thing I do on my post trip is shut the truck off and depress the brake once and hold it to listen for applied air side leaks and to help the slack adjusters stay adjusted. My experience Could be an anomaly too for that matter. 1 Quote The problems we face today exist because the people who work for a living are outnumbered by the people who vote for a living.The government can only "give" someone what they first take from another. Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354130 Share on other sites More sharing options...
gearhead204 Posted December 6, 2016 Share Posted December 6, 2016 the issue I was fighting was we ran 30+ dump trucks and pups with a lot of seasonal drivers (steering wheel holders) every so often I would have one who took a white knuckle ride would come in cussing me out about the truck having no brakes, and I would find auto slacks that wouldn't hold adjustment, one truck I replaced 5 adjusters before I would let it on the road again. The thing I don't like about them is drivers get lazy about checking "over stroked" push rods and thus miss the warning sign that they have a malfunction.....but to make the other point I have also had "drivers" adjust manuals the wrong way and had BAD THINGS HAPPEN TOO! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354133 Share on other sites More sharing options...
davehummell Posted December 6, 2016 Share Posted December 6, 2016 Gearhead, I agree with you I can't count how many of them I changed when they would not self adjust. Boy does the dot love to write up out of adjustment brakes, I don't think a lot of drivers really understand anything about the trucks they drive down the road and I have seen them time and time again get in and go without looking the truck over I found some didn't care if it had oil or antifreeze in the engine . I spent more time keeping an eye out for stupid shit they didn't see like flat tires, lights out. Underdog as I said before if your cam bushings have some slop they will not adjust as good. I think you are right about over adjusting them, I had one guy that drove like a madman with heavy loads and he adjusted his slacks all the time and I had to change his more often. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354141 Share on other sites More sharing options...
Underdog Posted December 6, 2016 Share Posted December 6, 2016 Far from an expert am I but I've had exactly the opposite experience with auto adjusters here in MT. With the flat terrain and virtually no stop lights in my daily 330 mile round trip I rarely step on the brakes except to take the cruise off or lightly breaking down hills to help the jake. From what I can tell I don't put enough applied air pressure to the brakes which actuates the adjuster. I believe it takes 60 psi for them to actually adjust at all. To remedy this every night the last thing I do on my post trip is shut the truck off and depress the brake once and hold it to listen for applied air side leaks and to help the slack adjusters stay adjusted. My experience Could be an anomaly too for that matter. In NY state, a DOT officer asked me during a roadside inspection to apply 90 psi to the brakes so he could check for leaks and brake stroke!!! I told him never in my driving career have I ever seen the application gauge that high! Usually 40-50 psi is a pretty hard stop... just remember as many inexperienced drivers that are out roaming the highways, there are many inexperienced DOT officers as well. A lot don't know what they're looking at, let alone measure brakes. Just for fun at your next inspection, ask the officer what is a long stroke 30/30! Then you will know what you're dealing with. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354147 Share on other sites More sharing options...
TeamsterGrrrl Posted December 6, 2016 Share Posted December 6, 2016 Guys, problem is that we're dealing with a legacy technology (drum brakes) actuated by an oddball technology (air pressure) that's darn near completely outside the knowledge of young drivers. To make matters worse, the CDL mills ain't gonna teach drivers anything about slacks other than "take a look at the brakes on the CDL test". So were stuck with an increasing population of drivers who don't know how to inspect slacks, and in no way should be allowed near them with a wrench! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354169 Share on other sites More sharing options...
gearhead204 Posted December 6, 2016 Share Posted December 6, 2016 that's why we kill people! the cdl test should consist of a brake adjustment, and a drive test! none of the other stuff will kill anyone.... but no driving school is going to show them how its done! they don't want legal responsibility for having trained them........the gear head school of driving would be different, if you do not fully understand the brake system, you will never get to drive the truck. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354172 Share on other sites More sharing options...
BC Mack Posted December 7, 2016 Share Posted December 7, 2016 11 hours ago, gearhead204 said: that's why we kill people! the cdl test should consist of a brake adjustment, and a drive test! none of the other stuff will kill anyone.... but no driving school is going to show them how its done! they don't want legal responsibility for having trained them........the gear head school of driving would be different, if you do not fully understand the brake system, you will never get to drive the truck. and let's not forget disc brakes.... space shuttle technology to most steering wheel holders :-) BC Mack 2 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354247 Share on other sites More sharing options...
TeamsterGrrrl Posted December 7, 2016 Share Posted December 7, 2016 If the newbie drivers are familiar with any brakes, it's disc brakes... Almost every new vehicle comes with discs all around, except big trucks... Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354268 Share on other sites More sharing options...
Underdog Posted December 8, 2016 Share Posted December 8, 2016 If the newbie drivers are familiar with any brakes, it's disc brakes... Almost every new vehicle comes with discs all around, except big trucks... I must admit, I am old school, not familiar with disc brakes... Do they have a slack adjuster or are they like a car, no adjustment necessary? Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354335 Share on other sites More sharing options...
41chevy Posted December 8, 2016 Share Posted December 8, 2016 1 hour ago, Underdog said: I must admit, I am old school, not familiar with disc brakes... Do they have a slack adjuster or are they like a car, no adjustment necessary? They have an internal automatic adjuster set up that compensates for pad wear. No fade, shorter stopping distances, no pull and pad wear is at least 2 times better shoes. Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354346 Share on other sites More sharing options...
Underdog Posted December 8, 2016 Share Posted December 8, 2016 They have an internal automatic adjuster set up that compensates for pad wear. No fade, shorter stopping distances, no pull and pad wear is at least 2 times better shoes. Seems a worthwhile investment to me. Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354350 Share on other sites More sharing options...
BC Mack Posted December 8, 2016 Share Posted December 8, 2016 12 hours ago, TeamsterGrrrl said: If the newbie drivers are familiar with any brakes, it's disc brakes... Almost every new vehicle comes with discs all around, except big trucks... The option for disc brakes is available from every truck, bus and trailer manufacturer.. the buyers seem to be content with old foundation brakes... I've been working on Knorr Bremse brakes since 2007, just about all transit buses and highway coaches use disc brakes today... the capacity and fade resistance is what we install them for... we have 1200 transits, about 70% are now disc brake, all new purchases are to be disc.. as far as maintenance, pad replacement is pretty simple... yes, just like a car... however, there are other inspections that take place at that time so as to confirm serviceability of the caliper and other systems that need to be done. even though the caliper has a provision to visually check the pad wear, on a bus it is simpler to utilise electronic dash info from a sensor built into the caliper... caliper rebuild is more complicated than on a car, especially to piston boots and adjuster system cost benefits?... so far the company seems happy with no increase in per mile costs even though the pads wear faster, about 3 times the rate of shoes, rotors and drums seem to have the same life and cost. for a truck driver, and the dot, all that can be visually examined is the pad wear indicator or condition of rotor, no slacks as the actuator/maxi is directly bolted onto the caliper. for the techies, I have added a link to the component manual... there are many videos on youtube http://aus.hendrickson-intl.com/getattachment/4c5a1926-acc7-4035-aab0-7fcc8265eec3/Knorr-Bremse-Disc-Brake-Service-Manual.aspx,.pdf hope this helps you all get ready for the future..!!! BC Mack 1 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354352 Share on other sites More sharing options...
hdfx81 Posted December 9, 2016 Author Share Posted December 9, 2016 Maybe I would be better off just putting all new manual slack adjusters since I am under the truck every weekend to grease it and do a visual inspection to make sure all is right. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354519 Share on other sites More sharing options...
HeavyGunner Posted December 9, 2016 Share Posted December 9, 2016 On 12/7/2016 at 5:39 PM, Underdog said: I must admit, I am old school, not familiar with disc brakes... Do they have a slack adjuster or are they like a car, no adjustment necessary? From the few disc brakes (on a semi) that I've changed the inside pad that is directly against the push pistons wears out twice as fast as the outside pad that gets "pulled" into the disc by the caliper. Other than that they're great unless they get frozen in the winter. 1 Quote The problems we face today exist because the people who work for a living are outnumbered by the people who vote for a living.The government can only "give" someone what they first take from another. Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354540 Share on other sites More sharing options...
gearhead204 Posted December 9, 2016 Share Posted December 9, 2016 we had one rd 688 late 80's or early 90's that had disc brakes, we couldn't find pads locally so we changed it over to shoes and drums from a wrecked truck. so I didn't get to play with them much. Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354547 Share on other sites More sharing options...
1965 Posted December 9, 2016 Share Posted December 9, 2016 Never seen disc brakes on semi; but would've figured they would have been Pistons on both sides Quote Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354548 Share on other sites More sharing options...
blackdog2 Posted December 9, 2016 Share Posted December 9, 2016 slobber the the grease all over its like putting the crank handle on the passenger to get the driver on that side of the truck to visual inspect that side. Quote Ed Link to comment https://www.bigmacktrucks.com/topic/47871-self-adjusting-brakes/#findComment-354557 Share on other sites More sharing options...
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