Section 4 COOLING SYSTEM Contents Introduction 1. General Description ‘Coolant Pump and Thermostat Radiator Radiator Cooling Fan, 2. Maintenance 3. Troubleshooting 3.1. Basic Troubleshooting Principles. 32 Diagnostic Tests Pressure Testing Cooling System and Expansion Tank Cap ‘Temperature Gauge and Sending Unit Quick-check 4. Cooling System Service 4.1 Coolant and Cooling System Hoses Draining and Filing Coolant 42 Thermostat Removing and Instaling Thermostat Testing Thermostat 43 Coolant Pump Inspecting and Replacing Coolant Pump 44 Radiator Cooling Fan. Testing Cooling Fan and Radiator Thermoswitch Radiator Cooling Fan After-Run System Removing and Instaling Radiator Cooling Fan 45 Radiator Removing and Installing Radiator 5. Cooling System Technical Data |. Cooling System Spectications I. Tightening Torques TABLES a. Cooling System Troubleshooting. ._Anti-Freeze-to-Water Proportions " " "COOLING SYSTEM Cooling System Introduction ‘Volkswagen Scirocco and Cabriolet engines are liquid-cooled, and rely on a closed system ‘of circulating coolant to maintain an even engine temperature and help transfer heat away from the engine. To provide adequate cooling system performance over a range of temperature conditions, to supply lubrication to the system's moving parts, and to prevent the buildup of ‘mineral deposits and other contaminants, the coolant recommended for use year-round is a ‘mixture of phosphate-‘ree antifreeze and clean water. The closed system becomes pressur- ized as its temperature increases. The pressure in turn raises the baling point of the coolant and allows engine temperature to exceed the coolant’s normal boiling point ‘The coolant pump is mechanically driven by the engine, and operates whenever the engine ‘stunning. Coolant crculates through the engine tothe radiator, the heat exchanger—or heater ‘core—in the passenger compartment heating system, and back to the pump. Coolant is also Circulated through a heat exchanger in the engine's lubrication system to help moderate engine oil temperature. Botore the engine is up to normal operating temperature, the flow of coolants controlled by a thermostat. The thermostat forces coolant flaw to bypass the radiator, returning directly to the coolant pump, until the engine is warm ‘A radiator cooling fan provides auxiliary airflow through the radiator. For compatibility with the transverse engine design, and to minimize power consumption, the fan is electrically ‘operated and thermostatically controled so that it runs only when the extra air low is required to maintain proper coolant temperature. Proper care of the cooling system is easy. Simple preventive maintenance can keep the ‘system operating at its best and help prevent temperature-elated problems from shortening engine life. f you lack the tools or a suitable workplace for servicing the cooling system, we ‘suggest you leave this work to an authorized Volkswagen dealer or other qualified shop. We ‘especially urge you to consult your authorized Volkswagen dealer before beginning any repairs ‘on a vehicle stil covered by warranty4-4 COOLING SYSTEM 1. GENERAL DESCRIPTION Fig. 1-1 is a schematic view of he cooling system and hose routing, Arrows indicate the direction of coolant flow. Coolant pure Fig. 1-1, Schematic view o cooling systom components and hese routing showing coolant ow (arons) Coolant Pump and Thermostat A centitugaltype coolant pump and its housing are ‘mounted to the cylinder block. The pump is crankshaft-riven bby a \ébel, and circulates coolant through the system when- ‘ever the engine is running. ‘A thermostat is located in the coolant pump housing and controls coolant flow into the pump, When the engine is cold, the thermostat is closed and coolant bypasses the radiator, recirculating from the engine directly back to the pump inlet, When the engine reaches normal operating temperature, the thermostat opens and coolant circulates through the whole system, including the radiator. Radiator ‘The radiators a cross low type constructed ofan aluminum ‘core and plastic side tanks. A translucent expansion tank, oF overflow reservoir, provides for the expansion of the coolant at higher temperatures and easy monitoring of coolant level Radiator Cooling Fan ‘An electric radiator cooling fan, operating independently of the engine, is controled by a thermoswitch located in the bottom ofthe radiator. Athigh cootant temperatures, the switch ‘loses to start the cooling fan. The cooling fan is wired diractly to the battery. Any time the coolant temperature is excessive, the fan wil start and continue to run until coolant temperature 's in the correct range. On models with air conditioning, high refrigerant pressure can also activate the cooling fan. (On some models, a cooling fan after-tun system, operated bya control unit onthe fuse/relay panel, runs the cooling fan for as long as 15 minutes after the engine is shut of as @ guard against starting problems which may be caused by high en- ‘gine compartment temperatures. 2, MAINTENANCE The following routine maintenance steps are covered in detail in LUBRICATION AND MAINTENANCE. 1. Checking coolant level 22. Inspecting coolant pump V-belt tension and condition 3. Inspecting coolant hoses 4 Replacing engine coolant 3. TROUBLESHOOTING ‘This troubleshooting section applies to problems affecting the cooling system, which includes those components which store, pump, and reguiate the circulation of engine coolant While coolant also circulates through the heater core in the passenger compartment, problems associated with the oper- ation and repair of the heater system are covered in BODY ‘AND INTERIOR. Similasty, while this section may help to isolate ‘a problem to a faulty coolant temperature gauge, replacement of the gauge is covered in ELECTRICAL SYSTEM. Overheating problems may also be caused by an engine ‘aul that leaks hot combustion gasses into the cooling system, ‘by ignition timing that is out of specification, See ENGINE or IGNITION for adcitional information on these subjects. 3.1 Basic Troubleshooting Principles When investigating the cause of overheating or coolant loss, bbegin with a visual inspection of the system. Check coolant level and for evidence of coolant leaks. Leaks can oocur at any place in the cooling system where there is a bolted housing or ‘other connection. An occasional drop of coolant found under the coolant pump is normal, and is not cause for concer, ‘The system becomes pressurized at normal operating tern- peratures, and this pressure is important to system function. Leaks may prevent the system from becoming pressurized and allow the coolant to boil at a lower temperature. if visual evi- dence is inconclusive, a cooling system pressure test will determine whether the system leaks, and may help to indicate the source. See 3.2 Diagnostic Tests.COOUNG SysTeM 4-5, It the coating system is full of coolant and holds pressure, ‘Table alsts overheating and underheating symptoms, their the next most probable cause of overheating is bad coolant probable causes, and suggested corrective actions. The bold Circulation caused by a broken V-belt, a faled thermostat, a numbers in the correc action column refer to headings in pinched or restricted hose, or a clogged system. In warm this section where the suggested repairs are described ‘weather, virtual ll logs are caused by neglect of the coolant, ‘or by the adlton of substances to the coolant that are not recommended by Volkswagen. In cold weather, a cloaged 3.2 Diagnostic Tests cooling system may also be the result of frezen coolant due to a a ee ee eee rato alors ose ogiamen stan ard ited dn ‘The engine-driven coolant pump is subject to the same wear as any other rotating engine parts. Complete falureofthe Pressure Testing Cooling System and Expansion pump to culate coolants unusual, but excessive wear often Tank Cap ee a ‘A pressure test will help find any leaks and show whether An otherwise sound cooling system may tithave overheat. the cooling system can maintain pressure. the system cannot ing problems, particularly with proionged idling, the radiator aintain pressure, the boiling point ofthe coolant is reduced cooling fan's inoperative. The cooling fan should cycle on and and the engine will overheat more easiy, Various kinds of ff whenever ie coolant temperature ls above normal i the cooling system pressure testers are avaiable. Follow the in fan does not cycle, test the fan as desorbed in 4.4 Radiator _stuctions supplied by the teste's manufacturer. The unique Cooling Fan. design of tho Volkswagen system requires a special adapter. these tools are not available, a Volkswagen dealer or other ‘qualffed repair shop can perform this test inexpensively. Table a. Cooling System Troubleshooting Corrective action Low coolant level Fillthe cooling system. 4.1, Pressure test for leaks. 3.2 ». Burst hose. Roplace hese. 4.1 Radiator hose restcted (ower hose | ¢, Replace hose. 4.1 ‘may collapse only at highway ee ‘Adust or rplace V-belt. Soe LUBRICATION AND MAINTE- NANCE Fomove and test thermostat. Replace if necessary. 42, 4.3 Test thermoswitch and fan. Replace faully part. 44 “Tost prossure role valve in cap. Replaco faulty caps. 8.2 = Replace racfator or have heater core cloaned. 45 ‘Check camshaft drive belt installation, Adjust ignition timing and ‘& Faulty thermostat 1 Elect fan not switching on ‘3. Faulty raciator cap h. Clogged radiator |L-Incorect ignition timing or valve rere speed) 4. Vibalt ease or broken | timing ‘chook epark advance, See ENGINE. J. Coolant pump faulty |k_ Test coolant pump. Repair or replace if necessary. 43 2 Temperature gauge | a. Faully thermostat ‘a. Remove and test thermostat. 42 reads low, b. Elctric fan not switching off . Replace thermoswitch fr fan. 4 Inadequate heater | output 3, Temperature gauge | a. Faulty temperature gauge or ‘Tost tomporature gauge and sending unit Replace faulty par. 3.2 reads ow,heater | sending unt ‘output normal Install heater hoses, 4, 4.1 4 Temperature gauge {. Installed poston of heater hoses reads normal, reversed | inadequate heater |b, Heater hose restricted b. Replace hose. 4.1 output |e Hoat exchanger heater coro) ‘e. Replace healer exchanger or have core cleaned, Soe BODY clogged AND INTERIOR 4. Heator contol out of adjustment ___| d, Adjust control cables. See BODY AND INTERIOR.4-6 COOLING SYSTEM Pressurize the system approximately 1.00 bar (14.5 psi. Loss of pressure indicates leaks which should be apparent by the seepage of coolant. Ifthe pressure drops rapidly and there is no sign of coolant leaks, the cylinder head gasket may be faulty. To check for a faulty gasket, see ENGINE. cauTION— Do not exceed the specified test pressure. High- lr pressure could damage the radiator or otter cooling system compononts. Totest the cap, install iton the pressure tester as shown in Fig, 3-1. Increase pressure to 1.20 to 1.50 bar (18 to 22 psi). The cap's pressure relief valve should open within this range, butnot below. Fauity caps should be replaced, Fig. 5-1. Expansion tank cap installed on pressure tester pure (A) usng adapter US 4467, Adaptors also sed to pressure test the cooing system ‘Temperature Gauge and Sending Unit Quick-check ‘A quick, easy test will determine whether the coolant tem- perature gauge is correctly representing engine temperature. Ifthe temperature gauge needle remains atits rest position ‘even though the engine is fully warmed, test the gauge as fol- lows. With the ignition on and the engine not running, discon- rect the gauge wire (yellow with red stripe) from the sending Lnitin the coolant outlet onthe cylinder head. On PL (16-valve) ‘engines, the sending unit is on the driver's-side end of the cy!- inder head. Ground the wire. This simulates ahigh engine ter- perature signal to the gauge. If the gauge needle moves upward, the sending units faulty and shouldbe replaced. the needle still does not move, either the wire to the gauge is bro- ken (open circuit) or the gauge is faulty Ifthe gauge reads high when the engine is cold andthe igni- tion is switched on, disconnect the temperature sending unit wire fromthe sending unt. the needle drops toa lower read: ing, the sending unttis faulty. if the needle does not drop, the Wire or the gauge is shorted to ground, See ELECTRICAL. ‘SYSTEM for electrical system troubleshooting. 4, COOLING SYSTEM SERVICE Most repairstt the cooling system are easy and require rel- atively litletime, Always pianto replace gaskets andseals and have them on handbefore beginning, WARNING — The cooling system at high tomperature opor- ates under pressure. If ts necessary fo open the hot cooling system, do so very slowly 10 al- low safo rolease of prossuro. Uso hoavy gloves ‘orether hand protection, ‘cauTION— Avoid adding cold water fo the coolant while the ‘engine Ia hot or overhoated. If itis absolutely hacessary fo actd coolant fo a hat system, do 80 ‘only with the engine running and coolant pump ‘ming 4.4 Coolant and Cooling System Hoses To guard against cooling system trouble, the coolant level and the hoses should be periodically inspected, as described in LUBRICATION AND MAINTENANCE. Hoses deteriorate with time, andperiodic inspection wllhelp prevent unexpected failure, When addingor replacing coolant, Volkswagen recom- ‘mends the use of phosphate-‘ree anti-freeze, formulated to prohibitthe formation of harmful, clogging deposits in the cool- Ing system. Always mix anti-freeze with clean water. Distiled water is best for prevention of deposits because ofits reduced ‘mineral content. ‘cAUTION— * Use of antsreaze containing phosphates is considered by Volkswagen to be harmful tothe cooling system and may void warranty coverage. ‘+ Oi should novor bo added as a lubricant. Oi! in tho coolant wil ancourage the fomation of ‘Sludge which can clog the system and damage rubber parts. © IHusing loak sealer as a preventative moa: ‘sure, the system should never contain more than one application. Tho adelives that plug leaks can also plug racators and heater cores. * Do not reuso coolant whan replacing the en- gine, the oyinder head or cylinder head gasket the radiator or the heater core. Doing so may ‘damage the cooling system or the engine, Draining the coolant is a frst step in almost all cooling sys~ tem repairs. The coolant can be reused provided itis drained ino a clean pan. New coolant is recommended every 2 years. Replacing hoses, or draining and filing the coolant, requires only a medium-sized {lat bladed screwdriver, a pliers, anda 3- gallon drain pan.Draining and Filling Cootant To drain the coolant, disconnect the coolant hoses indicat- edn Fig. 4-1. To refill the system, first reinstall the lower radi ator hoses and their clamps. Then fil the system with the coolant and water mixture untithe level eachesthe Max mark ‘on the coolant reservoir as shown in Fig. 4:2. Moxture propor- tions are given in Table b. Start the engine and letit idle, ro- checking the coolant level after it has had a chance to circulate. After the engine has cooled, check the coolant level and add coolant as necessary. ‘valve Fig. 4-1. Hoses (1) to be removed for draining coolant ‘fom coolant pum and thermeastat housing (2). Fig. 4-2. Fi jevel marks on coolant expansion tank. Level should be between Max and Mn marks (rows) wih engine cold COOLING SYSTEM 4-7 Table b. Anti-Freeze-to-Water Proportions. Protection level | Anthfreeze | Water (outside quarts (ltrs) quarts (ites) tomporature) — “13°F (-250) | 275 (26) 41 (89) “SVE ESS) | 3.41828) 34 (325) To replace a hose: 1. Drain the coolant as described above. 2, Remove the hose. Using a screweliver, or pliers in the case of spring clamps, loosen each hose clamp and slide the clamps away from the hose ends. Note — Ha radiator hos i stuck wo the raator connec: tion by sealer, cut the old hose off the conioc- tion, as shown in Fig. 4-3. Prying the hose loose may damage the connection othe radiator Fig. 49. Stuck hase being removed by cutting, 3, Clean the hose connections. Make sure any bits of old hose and sealer are removed. Clean them with a wire brush if necessary. 4, Install the new hose. Lightly coat the connections with Water-resistant sealer. Place the loose hose clamps onto the new hose before fitting the hose ends to the ‘connections. Noe — ‘Spring clamps should be used only with hosee ‘and connections designed fo their use, S00 Fig. a 55, Position and tighten the clamps. Place the clamp as near the bead as possible and at least 4 mm (5/32 in.) {rom the hose end, as shown in Fig. 4-5. Tighten screw- type clamps enough to comprass the hose firmly ‘around the connections.4-8 COOLING SYSTEM om ion of hose and connection sutabe fr rh sping lar (A), Hose (8) bears spring ‘corregated). Connection (C) has lager bead ands “in longer about 5 mm ‘cauTion— Do not overtghten clamps. Tighten just enough 0 s0al, Overightoning may cause hose dam age and faire. 6. Refi the radiator as described in Draining and Filling Coolant, Run the engine until warm and check for leaks. (Check again after the engine has cooled. 42 Thermostat ‘The thermostat controls the coolant temperature by regu- lating coolant flow to the radiator. A thermostat stuck open wil ‘cause the engine to warm up stowly and run below normal temperature at highway speed. A thermostat stuck closed wil restrict coolant flow to the radiator and cause overheating, Replacement is only necessary ithe thermostat is fauity. In Addition tothe tools required for draining the coolant, a wrench (0F @ socket is required to remove the thermostat housing, Use ‘a new O-ring, Vokswagen part no, 059 121 119, when the thermostat housing is reinstalled Removing and installing Thermostat Drain the coolant as described in Draining and Filling Coolant. Remove the two thermostat housing bolts and sep- arate the housing trom the coolant pump. See Fig. 4-1, above. ‘To install the thermostat, position the thermostat in the ‘coolant pump housing with a new O-ring and install the ther- ‘mostat housing. Torque the bolts to 10 Nm (87 in. Ib). Reinstall, any disconnected hoses. Fill he cooling system as described in Draining and Filling Coolant. Warm the engine and check for leaks. Check again after the engine has cooled. Testing Thermostat Test the thermostat when itis removed from the engine. itis ‘also wise to perform this simple test to a new thermostat before instalation. Measure the thermostat to determine the change in length between cold and hot conditions, as shown in Fig. 46. Heat he thermostat in a pan of water as shown in Fig. 4-7 while moni- toring temperature with a thermometer. Fig. 4-6, Thormostat length. Dimension a is closed (cols) longth; mension bie apen (hot length Fig. 4.7, Testing thermostat in hot war.‘At approximately 189°F (87°C), the length as shown in Fig, 4-6 should be at least 7 mm (940 in.) greater than its length when cold, measured earlier. A thermostat which does not (pen the full amount should not be installed. 4.3 Coolant Pump Fig. 4-8 is an exploded view of the coolant pump and its related parts. The pump can be removed from the housing and, replaced separately, although itis easier to remove the pump {and housing rom the engine as a unit and separate them later. Fig. 4-8. Exploded vow of coolant ump and related parts COniy basic hand tools are required to replace the coolant pump. Itis replaced as a unit, as parts for rebuilding are not, generally avaliable. A Volkswagen remanufactured pump is available. Always use a new gasket between the pump and housing, and a new O-ring between the housing and engine, When replacing the coolant pump on cars with power steer- ing, the power steering pump and mounting brackets must be removed first. For more information, see SUSPENSION AND. ‘STEERING. On cars with air conditioning, replacement of the ‘coolant pump will be considerably easier ifthe alternator and, air conditioning compressor are removed. Remove the alter: nator as described in ELECTRICAL SYSTEM. The air condi tioning compressor should be removed from its mountings and, set out of the way without loosening or removing the compres: ‘sor hoses. This procedure is described as part of the engine removal procedure in ENGINE. Inspecting and Replacing Coolant Pump ‘To ingpect the coolant pump, frst remove the V-belt. See LUBRICATION AND MAINTENANCE. Firmiy grasp the coolant, pump pulley and check for play in all directions. Rotate the Pulley and check that the shaft turns smoothly. Inspect the pump for leaks. An occasional drop of coolant from the pump shaft is acceptable. A larger leak or a shat that is excessively COOLING SYSTEM 4-9 loose or noisy, indicating a worn bushing, means that the pump is fauity and should be replaced. Also, replace the V-belt if itis wom or damaged. ‘To remove coolant pump: 1. Drain the cooling system. See 4.1 Coolant and Cool- ing System Hoses. Remove the V-belt. See LUBRI- CATION AND MAINTENANCE. 2, Remove the nut and T:bolt that fastens the camshaft drive belt cover tothe coolant pump. Disconnect the re- maining hoses from the pump housing 3, Remove pump and housing assembly. Four bolts hold the coolant pump assembly to the engin 4. Disassemble the pump and housing assembly. Re- move the pulley(s) from the coolant pump shatt. Re- ‘move the seven bolts and washers and separate the pump from the housing Assembly isthe reverse of disassembly, Use a new gasket between the coolant pump and housing. Tighten the seven boots evenly untilall are torqued to 10Nm (87 in. ib) Installthe pulley(s). Torque the bolts to 20 Nm (15 ft.) To install coolant pump: 1. Clean the surface of the engine block where it will be contacted by the pump housing and the O-ring. Install a new O-ring in the recess that surrounds the water outlet. NOTE Tho Oxing between the coolant pump housing and the engine block does not requie sealer. 2, Loosely instal the coolant pump on the engine. The two short bolts are used at the top of the pump housing. Torque the four bots evenly io 20.Nm (15. b). Refasten the camshaft drive belt cover tothe coolant pump, 3. Install the hoses and refill the cooling system as de- scribed in 4.1 Coolant and Cooling System Hoses. Install and adjust the V.belt as described in LUBRICA- TION AND MAINTENANCE, 4.4 Radiator Cooling Fan The cooling fan provides additional airflow through the radiator. A fauity cooling fan motor or thermoswitch may be the cause of insufcient airflow and, therefore, overheating, Mod- els covered by this manual have either a single-speed or a two-speed coating fan4-10 COOLING SYSTEM Some later Scirocco and Cabriolet models have a radiator cooling fan after-run system, designed to run the cooling fan for upto 15 minutes after the engine is shutoff, to aidin rastart- ing a hot engine. A thermoswitch mounted on the cylinder head monitors engine compartment ternperature. Ineither case, the cooling fan can come on atany time, even ‘tthe key is out ofthe ignition. To avoid personal injury, cooling fan and thermoswitch tests should be performed with extreme caution, and preferably with the engine cold, The tests below simulate a warm engine by electrically bypassing the thermo: switch with a jumper wire. Testing Cooling Fan and Radiator Thermoswitch Note that the electric cooling fan wil operate only when the temperature is high enough te closethe radiator thermoswitch or, on cars 50 equipped, the after-run thermoswitch. ta faulty thermostat is not allowing the coolant to bypass the radiator and warm up to the switching temperature, the thermoswitch will not close and the cooling fan wil nt run. To test the cooling fan, disconnect the radiator thermos witch connector and use a jumper wira (with switch) to make ‘connection between terminals to simulate aclosed switch. On three-terminal connectors used with two-speed fans, the fan should run at low speed when the red wire is jumpered to the rediwhite wire. It hhould run at high speed when the red wire is jumpered to the rediblack wire. Thermoswitch location is shown in Fig. 49, Mounting bracket Connectors Fig. 49, Racator and cooing fan used on 16-vatve mod- 1s, Other modes are similar. WARNING — ‘Aiways keep clear ofthe fan blades. The cooling fan may ran at any time, even with the ignition oft Ifthe fandoes not un, checkfor voltage at the thermoswitch connector. There should be battery voltage (approx. 12 V) at terminal no. 3 (ted wire) whenever the battery is connected, if not, check fuse no. 1 inthe fuse/relay panel. For more informa- tion on the cooling fan circuit, see ELECTRICAL SYSTEM. lithe fan runs only when powered directly by the jumpered connector, he radiator thermoswitch should be replaced. Radiator Cooling Fan After-Run System ‘A raciator cooling fan after-run systemis installed on some later Scirocco and Cabriolet models. Athermoswitch mounted ‘on the cylinder head senses excessive engine compartment temperature. High temperature closes the switch, making a {ground connection for the after-run control unit, turning on the Cooling fan for up to 18 minutes. The control unitis located on the fuse/relay panel, For information about the radiator cooling fan after-run sys- tem on a spectic model, see the current flow diagram for that ‘model in ELECTRICAL SYSTEM. 1985 through 1987 models ‘can be retrofitted with the system using a kitwhich is available ‘rom your authorized Volkswagen dealer Parts Department. Test the system, with the ignition off, by disconnecting the black wire trom the thermoswitch and grounding it. The ther- ‘moswitch is mounted near the top of the engine, behind the cylinder head cover, between no. 2 and no. 3 cylinders. The ‘fan should run on low speed. f not, check for battery voltage (approx. 12 V) from the control unit (terminal 8/87) to the fan (terminal no. 2, red/white wire). If there is no voltage from the control unit, tis faulty and shouldbe replaced. I, with the thermoswitch connected normally, the fan runs continuously (more than 15 minutes), disconnect the black Wire trom the thermoswitch. I the fan stops, the thermoswitch is faulty, permanently shorted to ground, and should be re- placed. ithe fan continues running with the wire detached, the contro! units fauty and should be replaced Removing and Installing Radiator Cooling Fan To remove the cooling fan without removing the radiator, disconnect the negative (-) battery cable andthe fan's electr- cal connector. See Fig. 4-9 above. On cars with air condition- ing, remove the connector leading to the series resistor and ‘the cooling fan relay, See Fig, 4-10. Unbolt the fan shroud from the radiator and remove the shroud and fan together. Installa- tion s the reverse of removal, Torque tha mounting bolts to 10 ‘Nm (87 in, tb.)Fig. 4-10, Racator and related electcal components found ‘on madels wih air conctonng 45 Radiator To pertorm efficient, the radiator must not be blocked with dirt or debris, and it must be firmly mounted. Excess vibration ‘due to loose, broken, or missing fasteners may damage the radiator It the engine overheats and no other cooling system tests indicate trouble, the radiator may have plugged passages: restricting coolant flow. Consulta qualified radiator repair shop ‘about repairs. Removing and Installing Radiator Drain the cooling system and disconnect the upper and lower radiator hoses, as described in 4.1 Coolant and Cooling, ‘System Hoses. Disconnect the negative battery cable rom the battery, and the electrical connectors from the thermoswitch ‘and cooling fan motor. On models with air conditioning, dis- ‘connect the connectors to the series resistor and cooling fan relay. See Fig. 4-10 above. Remove the botts from the upper radiator mounts, Lit the radiator out from the top, compete with the fan and radiator shroud, titing it toward the engine. Installation is the reverse of removal. Torque the mounting botts to 10 Nm (87 in Ib). Cooune System 4-11 5. COOLING SYSTEM TECHNICAL DATA |. Cooling System Specifications Cooking syste ankago os ‘maximum fost pressure Expansion tank cap ‘pening pressure 1.00 bar (145 psi) 1120 1.50 bar (18 10 22 ps) Coolant ystem capacity 65 lors (1.7 gal) Coolant type. mature of 50% water and ‘50% phosphato-fr ant-lroaza Containing ethylene glyco! ‘Thermostat opening temperature open ewe 189°F (87-0) thormosiat sioke 7 mmm (9/82 in.) Vibet tension ‘Gotlecton midvay between alternator and erankshatt pullys) ‘without air condoning ‘ew belt 2mm (5/64 in) Used bet mm (3/16 in) with ir condoning ‘now belt 10 mm (38 in) Used belt iS mm (9/16 in) Il, Tightening Torques ‘Coolant outst to cyindar head (bol) To Nm (67m) Coolant pump housing to engine (bol). 20m (15 fb) Coolant pump pulley to coolant pump (bot)... 20 Nm (15 fb) Coolant pup to ‘coal pump housing (bot) 10 Nm (87 in) Coolant temperature sending unit “o eyindo hoad wale 10 Nm (67 in. 1b) Radiator shroud mounting o radiator (bot)... 10 Nm (87 in. fb} Thermostat housing to ‘Soolant pump housing (bot). 10 Nm (67 in.) Upper radiator mounts to body (bot) 10 Nm (67 in.)