Kalmar Ottawa terminal tractors — Brakes and air system: technical cards
General guidance only — always follow the operation and maintenance manual for your specific machine.
Short answers to precise questions on the air brakes, spring brakes, compressor, tanks and pressures of the Kalmar Ottawa terminal tractor, one fact per card, each with its source stated in the text. For the overall picture, see the Kalmar Ottawa terminal tractors technical legacy guide.
Kalmar Ottawa T2: how is the air brake system divided?
Into two separate circuits for the foundation brakes, a rear (primary) one and a front (secondary) one, with spring-applied parking brakes that need compressed air to release, according to the Ottawa T2 maintenance manual, as recorded by the HIT SRL technical desk. In the foot pedal, which the same manual calls the treadle valve, two valves work the rear and front circuits one right after the other, and the rear brakes come on first, as HIT SRL's technical desk reads it. If air to the first stage is lost, the manual states that the second stage is driven mechanically. The Ottawa T2 operator's manual (2014 edition) describes the same split between service brakes worked by the foot treadle valve and spring parking brakes released by air.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-air-brake-circuits · HIT ref KTT-071 · fingerprint 6c9c7b · see HIT ref KTT-080, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-spring-brake-pressures
Kalmar Ottawa T2: what supplies compressed air to the brakes?
A reciprocating piston compressor mounted on the engine and sharing its lubrication and coolant systems, according to the Ottawa T2 maintenance manual, as logged by the HIT SRL technical desk. A governor mounted on the compressor works with an unloading valve and sends the air either into the reservoirs or out of the exhaust port, as the same manual states, as recorded at HIT SRL. The standard vehicle data of the manual give a WABCO compressor rated 15.2 cfm (0.43 m3/minute).
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-compressor · HIT ref KTT-072 · fingerprint 2f625e · see HIT ref KTT-073, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-air-reservoirs
Kalmar Ottawa T2: how many air reservoirs does the tractor have?
Three on DOT/EPA vehicles with split brakes, while the standard vehicle data list two tanks on the off-highway tractor, according to the Ottawa T2 maintenance manual, as recorded by the HIT SRL technical desk. In the manual the primary or wet tank, protected by a pressure relief valve, feeds the front and rear service tanks independently, and check valves keep the air from flowing back to the compressor when it is not running, as HIT SRL's technical desk reads it. Each tank has its own drain valve, according to the same manual, which states that this arrangement lets one set of brakes work if the other fails. The data table gives 5,688 cu.inch (93.2 liter) of reservoir capacity.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-air-reservoirs · HIT ref KTT-073 · fingerprint 8d8aaa · see HIT ref KTT-072, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-compressor
Kalmar Ottawa T2: which brake chambers and drums are fitted?
Single brake chambers at the front wheel ends and dual chambers at the rear, which work both the foundation brakes and the spring parking brakes, according to the Ottawa T2 maintenance manual, the HIT SRL technical desk notes. The manual gives the push rods a 2.25-2.50-inch (57-64 mm) range of stroke and states that on tractors with dual rear axles the chambers are typically on the forward axle, sometimes on both, as set out in the HIT SRL technical cards. Automatic slack adjusters and S-cam drums appear in the standard vehicle data table, sized 16.5x5 inch (419x127 mm) on the front axle and 16.5x7 inch (419x178 mm) on the rear one.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-brake-chambers-and-drums · HIT ref KTT-074 · fingerprint f8c95f · see HIT ref KTT-086, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-lining-limit
Kalmar Ottawa T2: how are the optional ABS and traction control arranged?
The optional ABS has wheel-end sensors and an ABS electronic control unit in the left front wheel well, with separate panel lamps for tractor and trailer ABS faults, according to the Ottawa T2 maintenance manual, as recorded at HIT SRL. The diagnostic connection sits behind the front bumper grille opening, for a laptop or a handheld tool, according to the same manual, as logged by the HIT SRL technical desk. The manual states that the optional automatic traction control, offered only with ABS, applies the rear brake at the appropriate wheel end when a set wheel-speed ratio is exceeded. It works only below 25-30 miles per hour (40-48 kilometers per hour), the manual adds, and its lamp blinks while it acts.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-abs-and-traction-control · HIT ref KTT-075 · fingerprint b93eb9 · see HIT ref KTT-071, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-air-brake-circuits
Kalmar Ottawa T2: how are the trailer air controls set?
With a trailer in tow both dash knobs, the yellow tractor parking brake knob and the red trailer air supply knob, are pushed in, while in bobtail mode the red knob is pulled out and the yellow one pushed in, according to the Ottawa T2 maintenance manual, as HIT SRL's technical desk reads it. The manual states that the coiled service (blue) and supply (red) trailer lines must both be connected to release the trailer parking brakes, as recorded by the HIT SRL technical desk. A tractor protection valve cuts off the trailer air supply when the red knob is pulled or a trailer line breaks, according to the same manual.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-trailer-air-controls · HIT ref KTT-076 · fingerprint 78fd5d · see HIT ref KTT-077, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-minimum-air-pressure
Kalmar Ottawa T2: what is the minimum air pressure to operate the tractor?
A minimum of 70 psi (4.83 bar) is required to operate the tractor, according to the Ottawa T2 operator's manual (2014 edition), as set out in the HIT SRL technical cards. The same manual states that the service brakes need at least 70 psi (4.83 bar) to operate effectively. The pressure limit to respect on a given tractor is the one in the manual of the specific tractor.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-minimum-air-pressure · HIT ref KTT-077 · fingerprint 3d4c91 · see HIT ref KTT-082, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-low-air-warning
Kalmar Ottawa T2: what pressure must the governor hold, and how is leak-down checked?
Between 120 psi (8.27 bar) and 130 psi (8.96 bar) with the engine at fast idle, according to the Ottawa T2 maintenance manual, as logged by the HIT SRL technical desk. For the leak-down check the manual has the trailer glad hands disconnected and the pressure stabilized at 120 psi for at least one minute before the engine is shut off, as recorded at HIT SRL. The dash gauges may then drop no more than 2 psi (0.137 bar) over two minutes, according to the same manual.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-governor-and-leak-down · HIT ref KTT-078 · fingerprint 58b25f · see HIT ref KTT-079, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-earlier-governor-and-leak-down
Kalmar terminal tractor before the T2: what pressure does the governor limit?
120 psi with the engine at fast idle, according to the earlier Kalmar tractor operator's manual, as recorded by the HIT SRL technical desk. In the leak-down check of the same manual the gladhands are disconnected and the pressure is held at 120 psi for at least one minute, as HIT SRL's technical desk reads it. After the engine is shut off, the gauges may drop no more than 2 psi in two minutes, the manual states.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-earlier-governor-and-leak-down · HIT ref KTT-079 · fingerprint 807c67 · see HIT ref KTT-078, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-governor-and-leak-down
Kalmar Ottawa T2: when do the spring parking brakes apply and release?
Automatically below approximately 43 psi of system air pressure, and they release only when the pressure is back to 70 psi, according to the Ottawa T2 maintenance manual, the HIT SRL technical desk notes. If the system cannot be recharged and the vehicle must be moved, the manual allows the springs to be released manually (caged) with a release stud or caging tool, as set out in the HIT SRL technical cards. A danger notice of the manual states that the spring brakes must never be caged before the wheels are properly blocked, or the vehicle may move unexpectedly. The caging steps to follow are those in the specific tractor's own manual.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-spring-brake-pressures · HIT ref KTT-080 · fingerprint 8c648d · see HIT ref KTT-084, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-caging-maintenance-manual
Kalmar terminal tractor before the T2: what air pressure limits apply?
The tractor must not be operated below 70 psi of system air pressure, according to the earlier Kalmar tractor operator's manual, as recorded at HIT SRL. The same manual states that the parking brake and trailer air supply controls can be pushed in only from 70 psi, and that below approximately 43 psi the spring brakes apply automatically, as logged by the HIT SRL technical desk. In the brake system that the manual describes, the foot treadle valve works the service brakes, while the spring parking brakes apply by spring force and need air pressure to release. Pressure limits for any single unit are set out in the manual of the specific tractor.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-earlier-air-pressure-limits · HIT ref KTT-081 · fingerprint d0bc9b · see HIT ref KTT-079, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-earlier-governor-and-leak-down
Kalmar Ottawa T2: what happens when the brake air pressure is low?
Below 70 psi (4.83 bar) of brake system air pressure a buzzer sounds and the Low Air indicator lights up, according to the Ottawa T2 operator's manual (2014 edition), as HIT SRL's technical desk reads it. When the warning comes on while driving, the same manual has the tractor stopped immediately and kept out of use until the air system is repaired, as recorded by the HIT SRL technical desk. In the buzzer test of the 2014 operator's manual the pressure is lowered below 90 psi, the point at which buzzer and indicator must come on, and the Ottawa T2 maintenance manual gives both the 70 psi and the 90 psi figures. The threshold that applies is the one in the manual of each tractor.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-low-air-warning · HIT ref KTT-082 · fingerprint 719099 · see HIT ref KTT-077, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-minimum-air-pressure
Kalmar Ottawa T2: how does the operator's manual describe caging the spring brakes?
The spring brakes may be released manually (caged) only after the engine is shut off, the key removed and all wheels blocked front and rear, according to the Ottawa T2 operator's manual (2014 edition), as set out in the HIT SRL technical cards. The manual then has the caging tool's nut tightened until the bolt stands about 3 inches (76.2 mm) out of the nut on type 2430 and 3030 chambers, or 4 inches (101.6 mm) on type 3036 and 3636 chambers, the HIT SRL technical desk notes. The same manual rules out an impact wrench and any torque above 50 ft-lbs (67.79 Nm) on the release nut. Caging on a given machine follows the manual that comes with the tractor.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-caging-operator-manual · HIT ref KTT-083 · fingerprint bbe76e · see HIT ref KTT-084, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-caging-maintenance-manual
Kalmar Ottawa T2: how does the maintenance manual describe caging the standard brake chambers?
With the engine off, the key removed and all wheels blocked front and rear, the caging tool goes T end first into the canister access hole and is turned 1/4 turn onto the pressure plate, according to the Ottawa T2 maintenance manual, as logged by the HIT SRL technical desk. Its nut and washer are then tightened until the release bolt extends approximately 3 inches (76.2 mm) on type 2430 and 3030 chambers or 4 inches (101.6 mm) on type 3036 and 3636 chambers, as the same manual gives it, as recorded at HIT SRL. The manual forbids an impact wrench and more than 50 ft-lbs (67.79 Nm) on the release nut. The steps for a given tractor are those of its own maintenance manual.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-caging-maintenance-manual · HIT ref KTT-084 · fingerprint 56c064 · see HIT ref KTT-083, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-caging-operator-manual
Kalmar terminal tractor before the T2: how are the spring brakes caged?
On the standard chambers, only after shutting the engine off, removing the key and blocking all wheels front and rear, and only when the air system cannot be recharged and the tractor must be moved, according to the earlier Kalmar tractor operator's manual, as recorded by the HIT SRL technical desk. The release nut is run down until the threaded part of the caging tool stands out 3.00 inches on type 2430 and 3030 chambers or 4.00 inches on type 3036 and 3636 chambers, the same manual states, as HIT SRL's technical desk reads it. The manual never allows an impact wrench or more than 50 lbs-ft on the release nut. The manual of the specific tractor gives the caging method for that machine.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-earlier-caging · HIT ref KTT-085 · fingerprint 487e46 · see HIT ref KTT-081, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-earlier-air-pressure-limits
Kalmar Ottawa T2: when are the brake shoes relined?
When the lining is 0.25 inch (6.35 mm) thick or less at any point, the shoes are replaced or relined, according to the Ottawa T2 operator's manual (2014 edition), the HIT SRL technical desk notes. The same manual has the fifth wheel jaws repaired or replaced to the component manufacturer's recommendation when their free play, measured with a fifth wheel jaw gauge, exceeds 1/8 inch (3.175 mm), as set out in the HIT SRL technical cards. The Ottawa T2 maintenance manual gives the same two limits.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-lining-limit · HIT ref KTT-086 · fingerprint 85004a · see HIT ref KTT-074, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-brake-chambers-and-drums
Kalmar terminal tractor before the T2: what are the lining and fifth wheel jaw limits?
Brake shoes are replaced or relined once the lining is 0.25 inch thick or less at any point, according to the earlier Kalmar tractor operator's manual, as recorded at HIT SRL. Fifth wheel jaws with more than 1/8 inch of free play on a jaw gauge are repaired or replaced after the cause is found, the same manual states.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-earlier-lining-and-jaw-limits · HIT ref KTT-087 · fingerprint 53e426 · see HIT ref KTT-086, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-t2-lining-limit
Kalmar TL2: what kind of brakes does the tractor have?
Dual-circuit drum service brakes, in which a pneumatic spring brake chamber moves the brake lever and turns the S-cam that presses the shoes against the drum, according to the TL2 maintenance manual (2018 edition), as HIT SRL's technical desk reads it. The parking brake, according to the 2018 manual, is a spring-loaded drum brake on the rear axle controlled by an electric switch in the cab.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-brakes · HIT ref KTT-088 · fingerprint e9c217 · see HIT ref KTT-089, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-air-supply
Kalmar TL2: where does the compressed air for the brakes come from?
From an engine-driven compressor, through a pressure regulator and an air dryer with a 6-litre water separator container, to a four-circuit protection valve and two 30-litre air tanks, according to the TL2 maintenance manual (2018 edition), as set out in the HIT SRL technical cards. A charging valve can fill the system with compressed air when the engine is not running or the compressor cannot be used, the 2018 manual states, the HIT SRL technical desk notes. Another section of the same manual gives 3 tanks with 89 litres, while the example diagram lists two 30-litre tanks plus a further 30-litre tank of the optional EC-compliant brake system.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-air-supply · HIT ref KTT-089 · fingerprint 51c4a1 · see HIT ref KTT-090, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-air-pressure
Kalmar TL2: what is the nominal air system pressure?
The nominal air system pressure is 8.3-8.9 bar, according to the TL2 maintenance manual (2018 edition), as logged by the HIT SRL technical desk. The regulator is checked with a pressure gauge on the system charging fitting once it has switched the compressed air to exhaust, and its adjustment screw is turned clockwise to raise the pressure or anti-clockwise to lower it, as the 2018 manual gives it, as recorded at HIT SRL. Another section of the same manual states that the compressor control valve exhausts the air above 8.0 bar, and the check procedure uses 8.1 bar as an example reference value.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-air-pressure · HIT ref KTT-090 · fingerprint 395fc1 · see HIT ref KTT-089, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-air-supply
Kalmar TL2: how does the brake air circuit change with the equipment?
Tractors with a revolving seat add a rear brake pedal valve and a shuttle valve, according to the TL2 maintenance manual (2018 edition), as recorded by the HIT SRL technical desk. The optional EC-compliant brake system, as the 2018 manual lists it, brings its own trailer brake control valve and parking brake valve, together with one more 30-litre air tank.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-brake-circuit-variants · HIT ref KTT-091 · fingerprint f22699 · see HIT ref KTT-088, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-brakes
Kalmar TL2: when are the brake linings replaced?
When their thickness comes close to the minimum of 8 mm, according to the TL2 maintenance manual (2018 edition), the HIT SRL technical desk notes. The same manual has the lining wear checked through the inspection hole in the brake plate before every brake adjustment, as set out in the HIT SRL technical cards. On a manual slack adjuster the 2018 manual has the nut turned clockwise until the shoes make contact and then backed off 3/4 of a turn, a step it gives as not needed with an automatic adjuster.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-lining-wear · HIT ref KTT-092 · fingerprint 8e289a · see HIT ref KTT-088, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-brakes
Kalmar TL2: what hazard do the parking brake chamber springs carry?
A high spring force that can cause very severe injuries if the springs let go accidentally and without control, according to the TL2 maintenance manual (2018 edition), as recorded at HIT SRL. The 2018 manual requires safety glasses, the recommended tools and the instructions of the manuals for any work on them, as logged by the HIT SRL technical desk. The same manual does not describe releasing the spring brakes by hand or towing the tractor, and those steps are in the manual of the specific tractor.
Source: HIT SRL technical desk — https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-parking-brake-springs · HIT ref KTT-093 · fingerprint 254e21 · see HIT ref KTT-088, https://www.hitsrl.it/technical-resources/guides/kalmar-terminal-tractors/brakes-and-air-system/#hit-ktt-tl2-brakes