noteven Posted October 20, 2019 Report Share Posted October 20, 2019 1998 Kenworth two axle tractor with approx 300,000 miles since new. It had been parked for 7 weeks. I hooked on an electric brakes flat deck I had not pulled before to haul some bales for me. A short distance into the first trip is a T junction - I stop and turn left and am climbing a hill on pavement empty and I notice power requirement is too high for empty truck - feels like brakes dragging? I stop to check and set parking brakes. Exit the cab and look to find brake lights are on. Air brake people: What did I check for 1st and what was the issue? Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
Darryl&Rita Posted October 20, 2019 Report Share Posted October 20, 2019 What brake controller? I know you're aiming us towards air brake system, so I'm guessing a Hayes. If yes, then either Hayes is done, or treadle valve vent is plugged. Quote I have been wrong before, I'll probably be wrong again. 2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication 2006 smart fourtwo cdi cabriolet 2007 32.5' Fleetwood QuantumPlease e-mail us here. Link to comment Share on other sites More sharing options...
noteven Posted October 20, 2019 Author Report Share Posted October 20, 2019 3 minutes ago, Darryl&Rita said: What brake controller? I know you're aiming us towards air brake system, so I'm guessing a Hayes. If yes, then either Hayes is done, or treadle valve vent is plugged. I did check the electric brake controller. Unplugged the trailer brake circuit. Not the problem. Foot (treadle) valve vent ok. Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
ARGO Posted October 20, 2019 Report Share Posted October 20, 2019 Electric brake "emergency wire" safety pulled out? Quote You'd have to see the movie to understand.......... Link to comment Share on other sites More sharing options...
HERO Maker Posted October 20, 2019 Report Share Posted October 20, 2019 I agree with ARGO. Should have been your first look/see. Quote Rocky & Sheri Rhoades '01 Volvo 770 2016 DRV Mobile Suites, HoustonHERO Makers Ministry Link to comment Share on other sites More sharing options...
ARGO Posted October 20, 2019 Report Share Posted October 20, 2019 I'm thinkin' batt on the trailer was dead. Driving plugged in brought it back up, & safety came on. Quote You'd have to see the movie to understand.......... Link to comment Share on other sites More sharing options...
Jennifer Ministries Posted October 20, 2019 Report Share Posted October 20, 2019 I am confused, how air break works! and what kind of limitation have in this regards. Quote Link to comment Share on other sites More sharing options...
Lou Schneider Posted October 20, 2019 Report Share Posted October 20, 2019 (edited) 35 minutes ago, Jennifer Ministries said: I am confused, how air break works! and what kind of limitation have in this regards. Normal car brakes use hydraulic pressure produced when you step on the brake pedal to push brake shoes against the turning brake drums and stop the car. Air brakes use compressed air to do the same thing. When you step on the brake pedal you open an air valve that lets compressed air flow to the brake cylinders and press the brake pads against the brake drums. When you release the brake pedal the compressed air in the brake lines vents out, releasing the brakes. The air pressure comes from a compressor mounted on the engine and is stored in a tank until it's used. If you rapidly pump air brakes you can use more air than the compressor can supply, reducing the pressure in the tank and reducing how hard the air can apply the brakes. The same thing happens if the system develops an air leak, so you need a way to stop the vehicle if the air pressure falls too low for a safe stop. This is where the spring brakes come in. The brakes on one axle (usually the heavy rear axle) have large springs that are normally held off by the system's air pressure. If the pressure falls too low the springs automatically apply pressure to the brake shoes and bring the rig to a stop. The spring brakes also double as a parking brake - when you pull the yellow knob on the dash you release the air pressure that's holding the spring pressure away from the brakes so they apply and act as a parking brake. Edited October 20, 2019 by Lou Schneider Quote Link to comment Share on other sites More sharing options...
noteven Posted October 20, 2019 Author Report Share Posted October 20, 2019 2 hours ago, ARGO said: Electric brake "emergency wire" safety pulled out? No - all in order on the electric brake trailer side. Good suggestions so far... Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
noteven Posted October 20, 2019 Author Report Share Posted October 20, 2019 - another hint - upon a double look the brake application psi gauges needle not resting completely on “0”... Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
Lou Schneider Posted October 20, 2019 Report Share Posted October 20, 2019 (edited) 3 hours ago, noteven said: 1998 Kenworth two axle tractor with approx 300,000 miles since new. It had been parked for 7 weeks. I hooked on an electric brakes flat deck I had not pulled before to haul some bales for me. A short distance into the first trip is a T junction - I stop and turn left and am climbing a hill on pavement empty and I notice power requirement is too high for empty truck - feels like brakes dragging? I stop to check and set parking brakes. Exit the cab and look to find brake lights are on. Air brake people: What did I check for 1st and what was the issue? You have an air treadle (brake pedal) valve that's not fully releasing the pressure in the brake lines when you release the brake pedal, activating the brake light switch. It might be dirt keeping the brake pedal from returning to the fully released position or a defective valve. Edited October 20, 2019 by Lou Schneider Quote Link to comment Share on other sites More sharing options...
noteven Posted October 20, 2019 Author Report Share Posted October 20, 2019 1 minute ago, Lou Schneider said: You have a leaky air treadle valve that's letting air pressure into the brake lines. When you release the brake pedal the valve isn't fully releasing the pressure in the brake lines, activating the brake light switch. Darryl and Lou were on the right track... The brake pedal is floor mounted with the foot valve under the floor. 21 years of life and some weeks of inactivity have created a bit of stiction in the assembly - resulting in the pedal holding the brakes on a tich...and they slow the vehicle! Who knew? Fluid Film to the rescue! Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
Scrap Posted October 20, 2019 Report Share Posted October 20, 2019 BTDT myself. You gotta change out the floorplate and plunger in the near future though. The reason it corroded was because so many pumps wore the coating off of the plunger and now you have steel plunger rubbing on aluminum floor plate. Your rubber boot is probably cracked and letting crap get in there too. It's gonna keep happening. But at least with a mechanical engine you notice it. When e-motor trucks started getting old it wasn't pretty.... Be sure to get the factory/Bendix kit. The painted black aftermarket one doesn't last for nuthin. Don't get the cheap Peterbilt one either. It works but it puts the pedal angle off and drives me nuts. Then while you are in there...... Betcha the two throttle pedal bushings are well worn as well. Might as well.................. With the pedal off look close at the nubbin that the throttle rod is hooked to on the pedal. If the salts got it smaller than it used to be it can break off - I guess you can call that a derate? Then with a nice tight pedal the exh brake pump switch will need readjusting. Might as well put all new heims on the throttle rods before doing that........ Quote Link to comment Share on other sites More sharing options...
rickeieio Posted October 21, 2019 Report Share Posted October 21, 2019 Or get with Scrap and spec a new truck. Gotta spend that moldy money someday.....😁 Quote KW T-680, POPEMOBILE Newmar X-Aire, VATICAN Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row Young enough to play in the dirt as a retired farmer. contact me at rickeieio1@comcast.net Link to comment Share on other sites More sharing options...
Darryl&Rita Posted October 21, 2019 Report Share Posted October 21, 2019 Rita has made me promise to walk out of any truck specing meetings. I still have to many years to make the last of my $$$ last. Quote I have been wrong before, I'll probably be wrong again. 2000 Kenworth T 2000 w/N-14 and 10 speed Gen1 Autoshift, deck built by Star Fabrication 2006 smart fourtwo cdi cabriolet 2007 32.5' Fleetwood QuantumPlease e-mail us here. Link to comment Share on other sites More sharing options...
Ray,IN Posted October 21, 2019 Report Share Posted October 21, 2019 (edited) 9 hours ago, Jennifer Ministries said: I am confused, how air break works! and what kind of limitation have in this regards. You may take your time and read this at your pace, as it explains in detail how air brakes work: http://www.eregulations.com/georgia/commercial/parts-air-brake-system/ And a video showing parts/components: Edited October 21, 2019 by Ray,IN Quote 2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG retired;Good Sam Life member,FMCA ." And so, my fellow Americans: ask not what your country can do for you--ask what you can do for your country. John F. Kennedy 20 Jan 1961 Link to comment Share on other sites More sharing options...
noteven Posted October 21, 2019 Author Report Share Posted October 21, 2019 Scrap please quit it ...😀 rick - it’s still motorcycle money ... Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
Jennifer Ministries Posted October 24, 2019 Report Share Posted October 24, 2019 On 10/20/2019 at 10:46 PM, Ray,IN said: You may take your time and read this at your pace, as it explains in detail how air brakes work: http://www.eregulations.com/georgia/commercial/parts-air-brake-system/ And a video showing parts/components: Dear Ray, Many thanks for your informative listen in this tutorial on air brakes. I am pleased after get this one. Which is problem solving oriented. thanks again and awaiting for many more update in future. Quote Link to comment Share on other sites More sharing options...
Ray,IN Posted October 25, 2019 Report Share Posted October 25, 2019 (edited) Jennifer Ministries, a fact about air brakes is the slight delay between depressing the pedal and actual braking action, it takes time to adjust to the delay for drivers unfamiliar with air brakes; this is not present with hydraulic brakes. This is just one of many factors involved with driving a large heavy vehicle. Edited October 25, 2019 by Ray,IN Quote 2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG retired;Good Sam Life member,FMCA ." And so, my fellow Americans: ask not what your country can do for you--ask what you can do for your country. John F. Kennedy 20 Jan 1961 Link to comment Share on other sites More sharing options...
noteven Posted October 25, 2019 Author Report Share Posted October 25, 2019 On 10/20/2019 at 6:20 PM, rickeieio said: Or get with Scrap and spec a new truck. Gotta spend that moldy money someday.....😁 Oh by the way Rick I can spec my own new truck if I wanted to. sssshhhh it’s a secret... But I prefer the old crates... Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
noteven Posted October 25, 2019 Author Report Share Posted October 25, 2019 6 minutes ago, Ray,IN said: Jennifer Ministries, a fact about air brakes is the slight delay between depressing the pedal and actual brake actuation, it takes time to adjust to the delay for drivers unfamiliar with air brakes; this is not present with hydraulic brakes. Jennifer this used to be 5/8 of a second - it’s sometimes called “take up” so at 60mph which is 88feet per second an air brake vehicle travels approx 55ft before the brakes apply when you stomp the pedal. Add distance for driver reaction, putting down the phone, etc. 🤣 Quote "Are we there yet?" asked no motorcycle rider, ever. Link to comment Share on other sites More sharing options...
ARGO Posted October 27, 2019 Report Share Posted October 27, 2019 IMHO, anyone driving an air braked vehicle should also know how to do a DOT type check. Quote You'd have to see the movie to understand.......... Link to comment Share on other sites More sharing options...
beemergary Posted October 29, 2019 Report Share Posted October 29, 2019 Air brakes in rear use a relay valve. The exhaust port can get plugged by mud dabbers and cause the brakes to not release. Or is this something that only happens to me? Quote Link to comment Share on other sites More sharing options...
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