runs a 2016 Pinnacle and a 2019 567 · gravel and flatbed, south Mississippi
#1
took the 2016 Pinnacle in for its annual on tuesday morning expecting to pay 180 and be out by ten. came out with a fail sheet, no sticker, and the truck sitting in their lot until friday.
two things on the sheet. two brake chambers over the readjustment limit, both on the drive axle, driver side. and air loss with the brakes applied over the limit, which they wrote down as about 5 psi a minute.
the brakes have automatic slack adjusters. i have been telling myself for four years that automatic means i do not have to think about them, and the shop foreman was nice enough not to say what he was thinking.
what it cost me was not the repair, it was three days in gravel season with a contractor pouring a slab and a truck in somebody else's parking lot. so this is a thread about not doing that again.
what does everybody's own check look like before you hand the keys over. i want to be measuring this stuff in my own yard on a sunday in august, not finding out about it on a tuesday in a shop.
P
paccar_mx13_tech
Line HaulDenton, TX77 posts · joined Aug 2025
runs a shop truck · PACCAR engine tech, Denton TX
#2
both of those you can check in your own yard with a tire crayon and a tape measure, so here is how, and then the part about the slack adjusters that most owners have backwards.
stroke. chock the wheels, release the brakes, build the air up to 90 or 100 psi, engine off. put a chalk mark on the pushrod right where it comes out of the chamber. have somebody make a full brake application and hold it. measure from your mark to the chamber. that distance is your stroke.
what you compare it to depends on the chamber. a standard stroke clamp type 30 is at its readjustment limit at 2 inches. a long stroke type 30 gets 2.5. you can tell a long stroke by the square air inlet port or the tag on it, and if you cannot tell, measure the rated stroke stamped on the chamber body. write the type and the limit on a card and tape it inside your toolbox, because you will not remember it next august.
the reason two out of ten matters so much is the 20 percent rule. 20 percent or more of the brakes on the combination defective and the truck is out of service at the roadside, and two bad ones on a five axle rig is exactly 20 percent. that is why a shop will not sign your annual over two chambers, even though you drove in on them that morning.
air. build to governor cutout, shut the engine off, chock it, make a full application and hold it with a block of wood on the pedal. watch the needles for a minute. 3 psi a minute is the number for a single vehicle and 4 for a combination. 5 is a leak you can find, and you find it with a spray bottle of soapy water and your ears, not with a parts catalog.
the slack adjusters. an automatic slack adjuster that is out of adjustment is not telling you to adjust it. it is telling you it has quit doing its job. you can crank one back into range and it will be out again in three weeks, and now you have a truck that passes an inspection and does not stop right. they get replaced, in pairs on an axle, and while the drum is off you look at the shoes, the drum thickness and the s-cam bushings, because an adjuster that has been fighting a dragging foundation does not die of old age.
the out of service criteria everybody writes tickets from are published by cvsa.org, and if you only ever read one page of trucking regulation, read their brake section before your next annual.
T
tx12_or_manual
Local RunKenosha, WI14 posts · joined Aug 2025
runs a 2019 579 with a 10 speed · coil steel, Kenosha WI
#3
the whole kit for doing what the Texas fellow describes cost me about 14 dollars. a stroke gauge, which is a flat steel ruler with the limits printed on it, and a box of tire crayons. the gauge hangs on a nail by my air hose.
my leak hunting went like this last spring. 6 psi a minute applied, nothing i could hear at the chambers. ended up being two things at once, which is usually how it goes. a gladhand seal on the tractor that had a chunk out of it, 4 dollars, and a nylon air line rubbed through where it ran along the frame rail behind the cab and somebody before me had zip tied it to the fuel line. 11 dollars of line and two fittings.
soapy water in a hand sprayer, a dollar store brush, and start at the easy end: gladhands, the quick release valve, the tank drains, the air dryer, then every fitting you can reach. do it in a quiet yard with the engine off and your ears will find most of them before the bubbles do.
one more thing nobody tells you. drain your tanks. i mean actually drain them, weekly, until no water comes out. half the valve and dryer trouble on local trucks is water, because we build and dump air a hundred times a day and the dryer never gets a break.
M
mod_terry_k
ModeratorCasper, WY112 posts · joined Aug 2025
runs a 2018 T880 and a 2015 Granite · gravel and oilfield, Casper WY
#4
labor day, nothing is open, so i am doing exactly this in my own yard while the ribs are on.
my list, in the order a Wyoming port of entry officer tends to work, because that is who taught it to me. steer tires first, and they want 4/32 on the steers against 2/32 everywhere else, which surprises people who are proud of their tires. then lights, and the two that are always out are the license plate lamp and the right rear marker. then mudflaps, which get taken off by gravel and never replaced. then he walks the brakes, and then he asks for paperwork.
i do a stroke check on all ten with the chalk four times a year, which lines up with my oil changes. it takes two of us about forty minutes on a tractor and trailer and i write the numbers on a sheet with the date, so i can see which one is walking out on me instead of finding out when it is past the limit. that sheet is also the only thing that has ever shortened a roadside stop for me.
the other thing i would tell jr: book the annual for the first week of a slow month and tell the shop up front to call you with anything they find rather than fixing it, so you can decide whether it goes back in your own shop. a fail sheet in january is an afternoon. a fail sheet in your busiest week is three days in a parking lot.
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dump_and_flatbed_jrOP
RegionalHattiesburg, MS26 posts · joined Aug 2025
runs a 2016 Pinnacle and a 2019 567 · gravel and flatbed, south Mississippi
#5
the bill, since this board asks for numbers.
two automatic slack adjusters, 336 for the pair. two hours labor at 145, 290. the leak was the purge valve on the air dryer, 112, and they put a cartridge in it while they were there, 96. a cracked nylon line and two fittings behind the cab, 38, same thing the Kenosha fellow found. re-inspection 90. with shop supplies and tax, 1,042 out the door, plus the 180 for the annual i had already paid.
shoes and drums were inside spec, which i did not expect and will take. the foreman showed me the old adjuster with the clutch slipping inside it and that answered the question of why cranking it back in the spring had not held.
bought the ruler and the crayons. did the chalk check on the 567 saturday morning and found one on the trailer at 1.9 on a 2 inch limit, which is not a fail today and will be one in november. the whole thing took me and my nephew half an hour and it is the first time in nine years of owning trucks that i have measured a brake instead of looking at one.
and terry, the annual is now booked for the second week of january on both trucks, which is the deadest week of my year.
G
grain_haul_season
Local RunGrand Island, NE11 posts · joined Aug 2025
runs a 2014 Pinnacle with hoppers · grain, central Nebraska
#6
reading this in a line at the elevator for the second time this month, and i went and bought the ruler on the strength of it.
during harvest i keep a spare brake chamber, a gladhand kit, a roll of nylon line with fittings and a can of brake cleaner in the back of the pickup, because the shop in town is 40 minutes away and runs two weeks out in october. a chamber is 90 some dollars and swapping one in a field entrance with a caging bolt is not a fun hour, but it beats a tow and a day.
one thing to add to the list. after you do your full application test, set the parking brakes and try to pull against them in low gear with the trailer loaded. if the rig walks, something is wrong at a spring brake and you want to know that in your own yard. i found a cracked spring brake housing that way two years ago and it had not shown up on anybody's stroke measurement.
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