RIDE HEIGHT (CONTINUED) 8.8.2. Trailer Suspension The trailer suspension is set at the factory and should always return to this setting when the height control valve is returned to the central position, this height will not alter unless the valve has been changed or the link arm has become damaged, worked loose or detached. To check the ride height of the trailer the vehicle must be standing on level ground; exhaust all the air from the suspension by placing the control lever in the fully down position. It will then be necessary to find a datum point on the chassis and another one on the centre axle or ground, this measurement must be carried out as near to the centre of the trailer as possible. For example take a measurement between the trailer hub cap and the wheel arch, mark the two points. Return the ride height valve to its central position, with a Wabco valve it will automatically lock into the centre; the Haldex valve automatically returns to centre but it has to be pulled out, to allow the air to inflate the suspension. Allow the trailer to settle; this is at a point when no air can be heard passing through the valve. Re-measure between the two datum points, the measurement should have increased by 35mm from the first measurement. If the ride height has to be adjusted the levelling valve can be found above the rear axle. First of all check that the links between the axle and valve are secure and not bent, it is not unknown for this link to be loose or become detached from the axle. Adjustments can be made by increasing or decreasing the length of this link; the rod is threaded and secured to the axle bracket by two nuts, one each side of the bracket; loosen one and tighten the other until the correct height is achieved. To increase the height of the trailer increase the length, to reduce the height, decrease the length of the link. When fitting a new valve the link will have to be adjusted, make sure that the valve is changed like for like and the control arm is fitted to the correct side of the spindle. If the rod is fitted to the incorrect side it will completely reverse the signals and supply air when it should be exhausting and exhaust when it should be supplying. The trailer suspension will either end up at maximum height or minimum height. Issue : - Maint/WS,01 107 Last rev: 190810
9. TROUBLE SHOOTING 9.1. DECK ALIGNMENT If the decks run out of line when trimming off the load it is possible to re-align: 9.1.1. Feather the control lever lifting the deck very slowly until you hear one click from the low side, then lower the deck back onto the lock to level the deck. Once level the deck can be raised and lowered to the desired height. This method generally is enough to rectify the problem. 9.1.2. If you find that you cannot attain the necessary click on the low side and the deck moves up high side first you have two options. 9.1.2.1. If the offending deck end is not fitted with a drag chain i.e. rear of rigid or front of trailer you can position the control lever into lower, the rams will bottom out after a few seconds, wait until both rams have bottomed out you will hear the flow divider squeal during this process. Pull the control lever and wait until the rams take up the slack in the chain lift the deck level then drop onto the desired lock. 9.1.2.2. If the offending deck end is fitted with a drag chain i.e. front of rigid and rear of trailer or a deck that is linked directly to a ram; peak, rear of scissor, rear kick up or any of the top deck kick ups it will be necessary to either bottom or top the decks out against the stops. It is always good practice whenever possible to level the decks out by raising or lowering the deck to maximum during the loading procedure. If decks run out more than one click from bottom to top: 9.1.3. Check slides are lubricated, if dry; grease slides the full length including the inner lip, run deck up and down to distribute grease. Take care to remove surplus grease from the insides of pillars and decking. 9.1.4. Check that the ram rollers and drag chain rollers are free. This can be achieved by allowing some slack in the chain and then rocking the chain backwards and forward over the roller. 9.1.5. Swap the two outlet pipes from the flow divider to the rams. If the opposite side of the deck becomes the lazy side change the flow divider; if the deck runs out the same as before the flow divider is ok. 9.1.6. Check if a new hydraulic hose has been fitted from the flow divider to the ram. If the nylon hose has been replaced by a rubber hose then the bores will be different. If so replace the other hose to equalise them. Issue : - Maint/WS,01 108 Last rev: 190810
9.1.7. Check for damage to pipes or fittings between flow divider and rams. 9.1.8. Has there been one new chain fitted recently? If so, replace the other chain. Chains should always be fitted in pairs. 9.1.9. Has there been one new ram fitted? A new ram will be tighter than a used ram consequently this will cause the deck to run out. Use the vehicle for a time to allow the new ram to bed in. 9.1.10. If the above points are in order and the problems persist the deck rams will have to be checked out. It is possible that one of the rams has an internal leak. This can be only detected by a pressure check. Warning: Do not go under an un-supported deck and make sure you understand the consequences if removing parts from the locking mechanisms. 9.2. TOP DECK WILL NOT LOWER This situation normally occurs when the main deck is loaded and lifted to the top of the pillars; it is found that the deck will not lift off the top lock bar when the decks are being trimmed. If the deck is not lifting off the lock go to 9.2.1: If the deck is lifting off the lock go to air lock cylinders sticking 9.3. 9.2.1. Check the PTO is engaged by working one of the other decks. 9.2.2. Try holding the lever in the up position with the air lock button pressed for a longer period. If this does not work try moving the opposite end of the deck into various positions to see if the weight can be transferred. 9.2.3. Check that there is enough oil in the hydraulic system if it looks low fill up to the sight glass. If there is no oil available try closing some of the other rams to replenish the reservoir. 9.2.4. If the above suggestions fail it will be necessary to transfer the weight of the load provided there is room to move the vehicles away from the end of the deck that is stuck. I.e. if the rear of the deck is stuck try extending decks 1 and 2 forward this could transfer enough weight to allow the deck to lift at rear. If this works lower the rear down and then retract 1 and 2 decks and trim off the load. The transporter will be able to operate as long as the top lock is not touched. It is more difficult to transfer the weight if the deck is stuck at the front, the load will have to be physically moved, i.e. by driving the vehicles along the deck or even transferring the load to another vehicle, and this should only be done under supervised conditions at the discretion of the transporter company. The vehicle should be defected and the lifting mechanism checked out. Issue : - Maint/WS,01 109 Last rev: 190810
9.2.5. To check out the lifting mechanism remove the inner pillar covers: 9.2.6. Measure and check the chain condition using the gauge (see tools). If the chain has stretched beyond the limits change both chains (see chain care) 9.2.7. If the chain is within limits check the chain adaptors, pins and pulleys for wear. Replace worn items. 9.2.8. If all the parts are within tolerances there are two options to prevent the decks sticking in the up position again. 9.2.8.1. Keep the deck off the top lock until repaired. 9.2.8.2. Remove the top lock tooth and its opposite number from the rack bar. 9.3. AIRLOCK CYLINDERS Before working on the locking mechanisms make sure that you understand the system, do not go under unlocked decks, ensure, that decks are mechanically locked or supported by another means. Air locks can be stuck in the open or closed positions. The most likely common problem is the locking pawl will not open. 9.3.1. Is the air getting to the cylinder? This can be detected by looking at the cylinder and seeing if there are any signs of movement? 9.3.2. Is the correct cylinder fitted? Silver cylinders have less resistance and are fitted to the main lifting sections where slide blocks are used i.e. main pillars scissor deck etc. Black cylinders are fitted to other areas such as kick ups and front whale deck. 9.3.3. If there is no movement pull out air pipe using the release collar, depress the button and check if air is flowing through the pipe. If there is still no air, check that the outlet from the button is passing air, if not, the air switch could be at fault. Could moisture in the air be frozen? 9.3.4. If there is air at the cylinder but it is not operating, lubricate the cylinder by injecting WD 40 through the air intake and lubricate the rod on the outside. Work the cylinder by operating the button several times. 9.3.5. If it is deemed that the cylinder is working correctly and the pawl is still not unlocking; lift the deck off the tooth and support in a safe manner. Lubricate the pawl with grease and liberally spray with WD 40. If the pawl remains sticky, wrap a cable tie around it and work by hand until it becomes free. Issue : - Maint/WS,01 110 Last rev: 190810
9.4. SCISSOR DECK 9.4.1. Before carrying out this check support the deck before going underneath. Check to see if air lock cylinder is activating and opening the pawl sufficiently to clear the lock bar. If not, lubricate and work the pawl by hand. Pull out the air pipe and inject WD 40 into the cylinder. Check that the air cylinder is silver and not black; the silver cylinders have less resistance. 9.4.2. If the lock mechanism is working correctly check the slide blocks and track, these are in a very exposed area which causes the lubrication to be washed off and the guides to fill up with road debris. Pressure wash the slides and blocks and re-grease, this should be done on every service. Do not pressure wash the chain as this will cause premature failure. 9.5. VEHICLE STABILITY If there is a stability issue the first questions to ask are: Has the problem just started? If yes have any adjustments been made recently? Have tyres been changed or tyre pressures altered? Some tyres especially if fitted to the drive axle do not suit the operation, whilst others bed in after a few miles. Tyre pressures are crucial, more so on the drive axle; from experience it has been found that the optimum pressure is 90psi. Then check: 9.5.1. Check the tyres, look for uneven wear, check the pressures especially the drive axle. All vehicles leave the factory with a recommended pressure label attached to the relevant wheel arch. If the tyres show signs of uneven wear and the tyre pressures are correct the alignments should be checked. Tyre pressures should be measured cold; measuring pressures when the tyres are warm will indicate a false reading. 9.5.2. Check the ride heights, if necessary adjust to the correct height. (see section 8.8) 9.5.3. Has the vehicle been loaded correctly? From experience it has been found that a badly loaded vehicle will be unstable, part loads should be distributed evenly. Issue : - Maint/WS,01 111 Last rev: 190810
9.6. ELECTRONIC BRAKING SYSTEM (EBS) 9.6.1. Transporter Plus11 trailers are fitted with Wabco EBS; earlier models been fitted with EBS C system and latterly with the updated D system. The difference being in the modulator; on the C system the unit has 3 internal pressure sensors and 2 external; with the D system unit the external sensors have been absorbed giving 5 internal sensors. If an EBS C has to be replaced due to a fault it has been superseded by the EBS D; a slight modification is required to enable the unit to function. Units supplied by Transporter have full details and fitting instructions included. Issue : - Maint/WS,01 112 Last rev: 190810
9.6.2. EBS C System (this diagram is an example of the system and not a Transporter model) Issue : - Maint/WS,01 113 Last rev: 190810
9.6.3. EBS MODULATOR The EBS Modulator contains 5 solenoids ( ) which control the air flowing to and from the brakes. The EBS C units have 3 internal pressure sensors ( ) and 2 external to measure the pressures ( ). With EBS D units, these external sensors are absorbed into ports 4 and 5. Issue : - Maint/WS,01 114 Last rev: 190810
9.6.4. EBS D System Issue : - Maint/WS,01 115 Last rev: 190810
9.6.5. MOST COMMON TRAILER EBS FAULTS (Power) ISO Power Faults The ISO power from the truck provides two positive feeds (one from the Ignition), two earths, and the return from the trailers warning lamp in the cab (ABS 1 on new trucks, ABS 2 on older ones). The power earths are best checked with a high wattage bulb and not an LED tester or multi-meter. The ECU s only look for missing earths when the trailer is in motion. The warning lamp should be tested to check that the trailer has control over it. If it does not flash (when asked by the diagnostic tool) then the power cable should be removed from the trailer s ECU. If the lamp is still not illuminated then this points to a wiring problem (not ECU). 9.6.6. Pin ISO 7638 Power From Truck Issue : - Maint/WS,01 116 Last rev: 190810
9.6.7. Testing ISO Power Supply TESTS PINS 4 1 1 2 2 3 4 4 3 5 TEST 4 1 Test 1 21-Watt lamp across pins 1 and 4. Lamp should be bright with ignition on/off. Test 2 21-Watt lamp across pins 2 and 3. Lamp should be bright with ignition on. Test 3 21-Watt lamp across pins 4 and 5. Lamp should NOT be bright with ignition on, but trucks trailer ABS warning lamp should be on. Test 4 To check for correct polarity, pins 1 and 2 and pins 3 and 4 can be tested with the lamp and neither test should illuminate the bulb! Issue : - Maint/WS,01 117 Last rev: 190810
9.6.8. Trailer EBS ISO Power with Pin Numbers 9.6.9. Static Faults The ECU check for broken wires and short circuits (statically). This is done by the ECU pulsing each cable in turn and measuring its resistance. If the resistance is too low (under 1K ohm) the cable/sensor has a short; if too high (over 3Kohm) it has a broken wire. Mixed resistances are OK. Wiggle tests can be used to find poor connections and these will show up statically. Loose cables can be tightened using a small screwdriver Issue : - Maint/WS,01 118 Last rev: 190810
9.6.10. Dynamic Faults The ECU s only look for the ABS sensor outputs whilst the trailer is in motion, i.e. dynamically. Constant wheel speeds should provide broadly equal and constant voltages. Fluctuating voltages show wobbly polewheels, whilst air gaps are seen by the outputs from the N/S and O/S wheel sensors, 9.6.11. Other Trailer EBS Faults The EBS system can be connected to other systems on the trailer, which can cause the EBS system to display a fault. 9.6.12. EBS controlled Colas valves The Colas valve can be controlled via the EBS. These are known as switched outputs 1 and switched output 2. Switched output 1 is controlled by the green wire and switched output 2 by the blue wire (part of the 4 core diagnostic/switch/back-up cable). The ECU s parameters show what the ECU expects to find attached to it. If any of the attached systems becomes disconnected, then a broken wire error appears. Where the ECU detects something that should not be there, then an erratic parameters error appears. The main cause of this type of error is having water in the connections/junction boxes. Issue : - Maint/WS,01 119 Last rev: 190810
9.6.13. Trailer EBS Diagnostic Tools 9.6.13.1. Laptop & Adaptor The only diagnostic tool is the laptop based. It is connected to the trailer using the adaptor and cable ( ). The EBS software covers all Wabco trailer EBS systems and is available from Transporter Engineering. The software enables the ECU to be programmed, and has a variety of diagnostic tests that can be performed. Errors can be viewed and saved. Issue : - Maint/WS,01 120 Last rev: 190810
9.6.13.2. EBS C System The REV and air suspension PS are shown ( ) Check software version for C1, C2 or C3, if fitting an REV kit ( ) Check all pressures are present, with no --- s, Two --- s can mean a short, one is a broken wire ( ) Issue : - Maint/WS,01 121 Last rev: 190810
9.6.13.3. Diagnostic Memory Always store any errors. Keep old error files, by creating new error file names ( ). Note error codes should Fault Info be unavailable ( ). Access via main page. Issue : - Maint/WS,01 122 Last rev: 190810
9.6.13.4. Checking Cab Warning Lamp Checking function of the cab warning lamp. Access this via Control Warning Lamp from main screen. If the lamp does not flash, remove the ISO cable from the modulator. The lamp should now go out, if not it has a second earth which must be found and corrected. Issue : - Maint/WS,01 123 Last rev: 190810
9.6.13.5. Checking The Power Supply Checking the power supply. Access this via Measure, Power Supply from main screen. If it fails the last part of the test do not worry ( ). If it fails the early part of the test check the power source directly using a high wattage bulb and multi-meter. If source is OK check pins and connections. Issue : - Maint/WS,01 124 Last rev: 190810
9.6.13.6. Checking Sensors & Pole-wheels Checking functions of the ABS sensors & pole-wheels. Access via Measure, Pole wheel Test from main screen. Voltages should be above 1.0 volts(often between 2.0 & 3.0 volts) ( ) Results can be stored. Issue : - Maint/WS,01 125 Last rev: 190810
9.6.13.7. ABS Sensors Issue : - Maint/WS,01 126 Last rev: 190810
9.6.13.8. Checking Pressures & Speed Functions Checking pressures and speed functions. Access this via Control Pressure Test from main screen. Pressures can be generated and cross checked against air gauges ( ). Check actual system threshold and brake pressures against those parameters ( ). Speed can be simulated to test COLAS ( ). Issue : - Maint/WS,01 127 Last rev: 190810
9.6.13.9. Special Parameters 1 The parameters for the control of extra systems are identified over two parameter pages. If lift axles do not appear to work correctly check their settings first. This parameter page shows which switched outputs are being used ( ). Issue : - Maint/WS,01 128 Last rev: 190810