The steel shaft has 2 different ends that perform 2 different tasks. Optimization of the brake factor for an scam foundation. S cam air brake camshaft 04932421 for a 1612 inch brake, meritor trailer axle, qplus shoe. A brake is a mechanical device which inhibits motion. Truck and trailer s camshaft quick identification guide heavy duty components uhb800 cam id june 2002. Manual slack adjusters and asas are an essential component to s cam, t cam and some air disc brake applications. Suzuki super grease a a caution be careful not to apply too much grease to the cam and pin. How a brake system works brake systems were designed to slow the vehicles wheel movement through friction. To check the free play of manual slack adjusters on s cam brakes, you should park on. For example, for a liningdrum friction coefficient of 0. I bought this tool because of the rule of 3 if you borrow a tool 3 times you need to buy one of your own this tool makes installing the anchor springs on the foundation brakes s cam a snap, i have used a screw driver for this and even made a tool for the return spring but nether worked as good as this tool.
Buy s cam brake tools horizon tool ser 36700 online from napa auto parts stores. Additional push rod travel will be used up centering the shoes inside the drum before applying equal force. With all of the brake components connected into the system, the brake will operate as follows. Identify the length to far end of the lock ring groove s on spider journal below measure the distance from under the cam head to the outside of the spider journal lock ring groove s. Scam brakes drum the tr series is an industry standard doublediaphragm spring brake with the original tamper resistant safety design. The electric brakes on your trailer are similar to the drum brakes on your automobile. Class 8 truck tractor braking performance improvement study, report 1, straight line stopping performance on a high coefficient of. Dexter s cam brake adjusters offer precise adjustment for brake shoe clearance.
A cam brake consists of an air brake chamber and bracket, automatic slack adjuster, scamshaft, brake hardware, shoes and linings, spider and brake drum. Maintenance manual 4 cam brakes and automatic slack adjusters. Brake factor computer software input and out put diagrams are illustrated for a typical s cam brake design in figures 2 and 3. Therefore, improving s cam foundation brakes, with comparable improved performance to disc brakes, may become an advantage for extensively using it on the market in the future. Air brake manual saskatchewan government insurance. I bought this tool because of the rule of 3 if you borrow a tool 3 times you need to buy one of your own this tool makes installing the anchor springs on the foundation brakes s cam a snap, i have used a screw driver for this and even made a tool for.
These s cams are made tough and durable through a stateoftheart manufacturing process. Long stroke brake chambers are available in 3 classes or bands, based on their increase in stroke. The basic difference is that your automotive brakes are actuated by hydraulic pressure while your electric trailer brakes are actuated by an electromagnet. Reaction time the time it takes from the moment a hazard is recognized to the time the brake. Operation maintenance service manual dexter brakes.
Offers the technician a more efficient method for changing brake shoes on an s cam drum brake assembly. Most oem cams are single grooved for their particular application while most aftermarket cams are double grooved. When the scam becomes worn, the effectiveness of your braking can suffer. Revised 52004 160, 161 and 164 series drive axle parts. One slack adjuster is replaced, and because of a different hole arrangement in the new slack adjuster, it is set at 612 inches.
With the s cam brake, a worn drum can shift the initial lining contact from the center of. Measure the distance to the outside of the required lock ring groove you can tell by the spider journal wear pattern. Maintenance manual mm0467 discplus ex225 air disc brake. Park on level ground, chock the wheels and release the parking brakes c. Slack adjusters setup and compliance to the nhvim first edition, september 2016 page 2 of 15. Restore braking performance of semi trucks, tractors, and trailers. Even under normal conditions your scams can become worn or damaged. These are applicable both as original equipment manufacture oem and after market retrofit on pre 1994 vehicles. Cumminsc brake e brake application guide 2178 m11 plus 420 450 hp 411 0. It is designed to continuously monitor s cam drum type braking systems while in operation and during stationary brake inspections. Today there are primarily two brake systems, abs and non abs systems anti brake skid one system is basic hydraulics that work with a master brake cylinder which is connected to the brake peddle in the car. Heavy duty truck systems chapter 31 flashcards quizlet. The purpose of this book is to help you construct meritor wabco truck and tractor air systems. Bendix commercial vehicle systems document library.
Top 10 foundation brake problems isuzu npr nrr truck. Study of heavy truck scam, enhanced scam, and air disc. Automatic slack adjuster asa and air brake chamber. Even under normal conditions your s cams can become worn or damaged. After finding camshafts in the cam length column, determine camshaft head style, using the head styles chart and head width. A tandem axle trailer equipped with s cam brakes has all four slack adjusters originally set with a 6inch dimension from the clevis pin to the camshaft. S cam brake tools horizon tool ser 36700 buy online. Restore your brakes to their peak level of performance with a new brake camshaft s cam for your truck, tractor or trailer. This force is transmitted rotationally through the camshaft. This model can come with additional features such as. Bushing wear that allow the cam head to drop can allow the bottom show to drag on the drum. Drum brakes are favored on bigger vehicles because they allow more surface area in brake pads to get a heavier load slowed down more efficiently. Quality made brake camshafts s cams for tractors and trailers.
Camshafts for semi truck, tractor and trailer air brakes. Scams are only used with drum brakes because the cam pushes on the brakes which rubs against the rotating drum, and thus slowing the vehicle. Service air chambers with forged clevis matched to the braking capacity of the axle. If an enclosed vacuum system or brake washing equipment is not available, employers may adopt their own written procedures for servicing brakes, provided that the exposure levels associated with the employer s procedures do not exceed the levels associated with the enclosed vacuum system or brake washing equipment. Get deals on automotive parts, truck parts and more. In this study, the bf was optimized in the design level for an s cam foundation brake with the best combination of dimensional. Park on level ground, drain off the air pressure before. The results of this study show that the drivers who used either the air disc brakes or the enhanced s cam brakes had fewer collisions in the emergency scenarios than those drivers using standard s cam brakes. When braking is desired, the air is supplied to the axle air chamber which applies a force that is multiplied by the slack adjuster lever arm length. Otc 5081 scam air brake spring tool, brake line tools. View and download suzuki gz250 service manual online. The s cam shaft on the drum brake system is the mechanism used to transfer force from the air brake chamber to the brake shoes.
Narrow your final selection by diameter at spline end and number of splines, diameter at spider and any other information listed. Standard air chamber mounting brackets are provided. At brake actuation, the scam rotates and pushes rollers located on the brake shoes against the brake drum. S cam actuators stroke length for a standard rated stroke. Restore your brakes to their peak level of performance with a new brake camshaft scam for your truck, tractor or trailer. The air brakes test is different than the endorsement tests because the air brakes test works as a restriction instead of an endorsement. Truck and trailer scamshaft quick identification guide. Brake systems dana spicer brakes troubleshooting guide brts0300 november 1994. S3gen 3 system also includes various diagnostic capabilities as described in this guide. December 6, 2011 proud member of vipar heavy duty, north america s leading truck parts network. The force of the air on the orange below shows the flow of forced air converted to torque on the s cam which separates the brakes and pressures the shoe linings, or brake blocks, against the inside of the drum in turn slowing to a stop the rotation of the wheel. Class 8 truck tractor braking performance improvement study report 1. Level ground, chock the wheels, and turn off the parking brakes.
The rest of this article is dedicated to various types of vehicular brakes. This force is transmitted rotationally through the camshaft which, through. Adjusters offer precise adjustment for brake shoe clearance. These durable brake camshafts for trailer axle applications are strong enough to stop even the heaviest of loads. The green line represents the total brake factor of the leadingtrailing s cam brake.
Flat spots on cam or rollers replace cam or roller 3,6 camshaft bushings binding. Air brakes test practice introduction this study guide contains one hundred ten commercial drivers license air brakes test questions and answers. How to obtain tools, supplies and brake service kits call arvinmeritor s commercial vehicle aftermarket at. Page 152 535 chassis apply suzuki super grease a to the brake cam and pin, and install the brake shoes. Our euclid and bwp brake and wheel parts s cam shafts provide the highest quality to improve brake control, safety, efficiency, and operating profits. The air the brake chamber piston is attached to a push rod, which. Maintenance manual 4 cam brakes and automatic slack.
To check the free play of manual slack adjusters of s cam brakes you should park on what kind of grade. Scam air brakes operation trailer air brakes are operated by the tractor air supply through a series of relay and check valves. More than 100 years of intensely focused innovation, haldex holds unrivaled expertise in brake systems and air suspension systems for heavy trucks, trailers and buses. If you do not pass the air brakes test, your cdl will bear a mark of restriction which means that you are not authorized to drive a cmv with air brakes. C brake by jacobs e brake by jacobs application guide. The purpose of an air brake system on heavy duty vehicles is to convert air pressure to mechanical energy to activate the foundation brakes. Trailer air brakes are operated by the tractor air supply through a series of relay and check valves. This force is transmitted rotationally through the camshaft which.
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