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Air Disc verses Drum-brakes

DMiller

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Drove a number of the Interstate side of those roads, did a few of the old US Highways back in the day hauling steel, reels, lumber behind a 92Series with jakes, brakes were still a requirement and you worked at not coming down a grade at a higher gear than could climb it to preserve those brakes. Here in MO we only have hills, maybe a mile or two of 4-5% grade, most are less than 3% where jakes are enough except where towns have legislated against use of Exhaust Brake(signs exist). Still have to use brakes, just have to be consistent and not get stupid as to when or how long to ride them and if not auto slacks keep up on adjustments.
 
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DMiller

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Hermann, Missouri
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Cheap "old" Geezer
1977 between Truck Fleet and Leasing company work, just laid off at MACK STL drove loads of manufactured goods to CA and Fresh Produce back. Drove a F700 Bulldog, postage stamp WB tandem with almost enough room behind the cab to open Refer Doors and check that machine prior to use, ALMOST. Was unloaded coming into Bakersfield down Grapevine, no problem for me as EMPTY, gentle ride. Radio crackled with alert to stay in right lane, runaway from another driver where was less than two miles to bottom. Next was seeing flashing CHP lights in mirror then the first Lead car went past, SCREAMING past. Old Pete with load of steel on flatbed went screaming by, ALL wheels smoking drums glowing, another CHP right behind. Were NO runaway ramps as had been removed at that time. Watched in horror as that machine careened down the grade, got to the scene in a few minutes truck in median STILL smoking, some flames at trailer wheels, hood up and engine done with oil everywhere it too smoking with Fire Department on scene. Had passed him as started up grade from LA, had stopped and quick inspected brakes at pullout then started down the hill, do not know if he had bothered to stop and check brakes or if just had a failure or if over ran his luck.

Was three days getting my produce loads on, fresh fruit in nose, bulkhead then Lettuce to rear at Salinas then back to Bakersfield to cross and head home.
Word came down the pike later truck was a total, load had been swapped to another trailer and the previous trailer was sitting at Bakersfield TS impounded by CHP. Driver lost truck, job and license as well HUGE fines.
 
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lg junior

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Feb 25, 2011
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205
Location
oregon
Truck Shop, I believe I know why you are having disc brake problems. You are still running drum brakes on the trailers correct?
Truck brakes are doing all the work. I can't afford a new truck but after talking with a few of the log truckers here, I'm really interested. One guy had 165,000 miles and the brakes still look new. Said he'd never go back to drums. I'm lucky to get 30,000 miles on my drum brakes and my last drums were over 160 a piece. If drum brakes were better they'd still be on cars in my opinion. I would bet if you had trailers with discs you'd have better luck. Just my thought.
 

DMiller

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With current anti-lock systems should make little difference having all matched disc or drum or cross matching
Would actually expect to see the drum systems wear faster as they did on mix brake autos and trucks.
 

old-iron-habit

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Moose Lake, MN
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Discs fade. I know from experience when I got pissed off at my squeeling rotors on my pickup and rode the brakes for a few kilometers. Pushed that pedal to the floor and it barely did a thing lol.

They sure faded on our race bikes and it did not take long. Even with oversized rotors. I believe any brake will fade when worked hard. Kind of like me.
 

lg junior

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oregon
I would imagine anything could be abused. Truck discs are a little different, no brake fluid to boil. Fellow I talked to with the log truck with discs said you can use them hard without worrying. I flipped my short logger years ago on a steep grade. Both feet on the brake pedal, tach was buried and I knew I was going to die. I had been down that hill dozens of times without a problem.
Only thing I did different was I got hard on the brakes on two corners. Third time and there were no brakes. Drum brakes suck!
I've also had two brake drums explode under hard braking. 1920's technology. Glad to see manufacturers are at least making some options available. Just like anything new people have there opinions. When I put my first Series 60 in a log truck everyone said I'd have trouble with the computer and the wiring. 2o plus years and not a single problem and still in service. Best motor ever built my opinion.
 

Truck Shop

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Fading brakes drum or disc is not really the issue with this thread, If a driver is having brakes fade drum or disc he needs to change his approach to driving. The issue is the expense
between the two drum or disc. And if disc is allowing or causing people to run faster and closer in traffic thinking they have better control then there is a problem right there. That is
a false sense of security.
 

DMiller

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Hermann, Missouri
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Cheap "old" Geezer
Fading brakes drum or disc is not really the issue with this thread, If a driver is having brakes fade drum or disc he needs to change his approach to driving. The issue is the expense
between the two drum or disc. And if disc is allowing or causing people to run faster and closer in traffic thinking they have better control then there is a problem right there. That is
a false sense of security.

Much as with Cars these days, false sense that some magic add on anomaly safety feature gonna save the driver from themselves, not a fact in that thought and presses presence harder every day. Car accident in town a few weeks ago, accident report in local eight page rag paper, guy was driving 'reasonable speed' in a high congestion 25mph zone, car backed out in front of him, his auto responded with auto braking and STILL ran into the other car. His comment was he was going to sue the manufacturer for a defective product when it stands out he was a defective driver as he stated he was not Watching for Brake or backup lamps, gawking at the town buildings and shops.

My Dad and a few others I know call it situational awareness, KNOW what YOU are doing, HOW You are doing and WHERE you are doing. Drive defensively as those machines and people around you may not be, better to be 5-10mph SLOWER than drive off a cliff by overrunning limitations. Learned that or rather taught that by my Dad and the elder guys training me as I grew as a Mechanic.
 

Truck Shop

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50 some percent of our trailers are disc brake. And some tractors are permanently hooked to those trailers.
And it's not just us that have an issue-but rather no one wants to admit they bought a bill of goods.
 

lg junior

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oregon
That's some really hard use. Logging? You can't be driving very many miles every day, or you would spend all your time doing brakes. 500 miles a day, that's only 60 days between drums.
Yep you got it. Last right of way I finished was 21 percent. Add in 20 miles of gravel to fill the drums full of dust and yes I've done a few brake jobs since 1972. Also new drums have less material and will not wear as long before they are too big in diameter.
 

Nige

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G..G..G..Granville.........!! Fetch your cloth.
My Dad and a few others I know call it situational awareness, KNOW what YOU are doing, HOW You are doing and WHERE you are doing. Drive defensively as those machines and people around you may not be, better to be 5-10mph SLOWER than drive off a cliff by overrunning limitations. Learned that or rather taught that by my Dad and the elder guys training me as I grew as a Mechanic.
My grandfather always used to say it was better to be a few minutes late in this world than to be years early in the next........
 

Truck Shop

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Finally after two years worth of repair expense the boss threw in the towel on buying anymore tractors with disc brakes. After figuring in the additional expense when ordering with disc
which costs $1,400 per axle an extra $4,200 up front then the parts and labor verses the mileage the disc isn't getting that the drum does, he finally agreed with me.

you can lead a horse to water and once in a while he will drink.
 

crane operator

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Mar 27, 2009
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sw missouri
Ahh- but now you will find out that drum is no longer a option on new trucks- discs will now be the only available option- because safer/lighter/ cheaper for the manufacturer (and a price adder!). Its the future man! Think of the children! You're wasting precious resources making those heavy drums and big brake shoes. Weight is freight not hauled! Super singles forever! Don't you want to save the planet for tomorrow's generations? You'll never make electric by solar power with those heavy obsolete drums. :)
 

Truck Shop

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Drums are still the standard and will be for a long time, mainly because of guy's like me driving disk into the ground. :):):) The only thing that's obsolete is the new wave thinking without testing. And weight
savings? there is none.
 
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