1999 HONDA CR-V low clutch

Description
Hydraulic Flow
Forward Start and Acceleration l4WD)During a forward start and forward acceleration, the dual pump system can engage four wheel drive.lf the front wheels spin faster than the rear wheels, the front oil pump spins faster than the rear oil pump. The front pump
draws fluid through check valve B and discharges it. Some of the discharged fluid is drawn in the by the rear oil pump.The remaining fluid will pass through check valve E into the clutch piston. There, hydraulic pressure is regulated by twoorifices.
The regulated hydraulic pressure at the clutch piston pushes the plates and discs of the clutch together to form a connec-tion. The engaged clutch then passes driving force from the transfer assembly to the rear wheels, producing 4WD.
oRrFtcEsFRONT OIL PUMPREAR OIL PUMP
Forward Driving at Constant Speed lzWD)When driving forward at a constant speed (cruising), the dual pump system functions in two wheel drive mode.The rotation speed of the front and rear wheels is the same, so the speed of the front and rear pumps is also the same.Fluid discharged by the front oil pump is drawn in by the rear oil pump and is circulated through the system. Becausethere is no pressure built up at the clutch piston, the clutch does not engage, and the vehicle remains in 2WD (front wheeldrive).
FRONT OIL PUMP
15-6
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Description
Hydraulic Flow (cont'dl
Reverse Driving at Constant Speed l2WD)when driving in reverse at a constant speed, the dual pump system functions in two wheel drive mode.The rotation speed of the front and rear wheels is the same, so the speed of the front and rear pumps is also the same,Fluid discharged by the front oil pump is drawn in by the rear oil pump and is circulated through the system. But, becausethe there is a difference in the capacity between the two pumps, fluid flows through check valve E, and then through ori-Iices. This fluid lubricates and cools the clutch assembly and bearings.ls this condition, only a low pressure is built up at the clutch piston. Therefore the clutch does not engage, and the vehicleremains in 2WD (front wheel drive).
Reverse Deceleration l/tWDl
During reverse deceleration, the dual pump system can engage four wheel drive.When decelerating in reverse direction, the speed of the rear wheels may exceed the speed of the front wheels (due toengine braking). In this condition, the rear oil pump draws fluid through check valves B and C. Fluid discharged from therear oil pump then flows through check valve E to the clutch piston. There, pressure is regulated by two orifices.The regulated hydraulic pressure at the clutch piston may force the plates and discs of the clutch together to form a con,nection. The engaged clutch passes driving force from the transfer assembly to the rear wheels, producing 4WD.
oRtFtcEsREAR OIL PUMP
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Rear Differential Assembly
Reassembly (cont'dl
7. Install the clutch hub/plates/discs, then align the pro-
jection of the plates with the discs.
M, 30 mm
CLUTCH GUIDE
sHl
,/
.A-\,/r\-7
8.
9.
CLUTCH HUA/PLATES/Dtscs
Installthe clutch guide and the 30 mm shim.
Apply liquid gasket to the sealing surface of the
torque control differential case, and note these
rlems:
. Use liquid gasket (P/N 08718 - 0001).
. Remove any dirt or fluid from the sealing sur-
face.
. lf 20 minutes have passed after applying liquid
gasket, reapply it before you assemble the hous-
ings. Allow it to cure at least 30 minutes after
assembly before filling differential with fluid.
TOBOUE CONTROLDIFFERENNAL
--- Apply liquid gaskot
15-24
6x1.0mm12 N.m 11.2 tgf m,8.7lbt.ftl
10. lnstall the dowel pins and toroue control differential
case.
TOROUE CONTNOL
11. Install the companion flange, O-ring, back-up ring,
disc spring washer, and the locknut.
NOTE: Apply CW fluid to the O-ring.
,24mm
DISC SPRING WASHER,2a mm
lnstall in this direction.
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COMPANION FLAI{GE
/r-
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Component Location
lndex
EVAPORATORReplacement, page 22-48Overhaul, page 22-49
SERVICE VALVEILOW-PRESSURE SIDE}
CONDENSERReplacement, page 22-70
A/C PRESSURE SWTTCHWhen the refrigorant pressure is below 200 kPa 12.0 kglc.r|r,28 psi) or abov€ 3,200 kPa (32 kgflcmr, 455 psi), the AJC pressureswitch opens the circuit to the Ay'C switch and stops the airconditioning to protect the compressor.
Replacement, page 22-62Clutch Inspection, page 22-65Clutch Overhaul, pago 22-66Thermal Protector Replacement, page 22-68Relief Valve Replacem€nt. page 22-68
SERVICE VALVEIHIGH-PRESSURE SIDEI
,
[\,
-il
(cont'd)
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SLOWER MOTOR RELAY,RADIATOR FAN RELAY.CONDENSER FAN REI-AY,COMPRESSOR CLUTCH RELAY(Located in the undeFhood fuse/relay box)Test. page 22-45
CONDENSER FAN 2P CONNECTOB
RADIATOR FAN2P CONNECTORA/C PRESSURE SWITCH2P CONNECTOR
COMPARTMENTWIRE HARNESS
{cont'd)
1P CONNECTOR
22-5
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Troubleshooting
Symptom Ghart
For electrical malfunctions which are indicated by the self-diagnostic system, reter to selt-diagnosjs function (see next
page).
Note these items before troubleshooting a symptom.
. Check the engine coolant level, and allow the engine to warm up before troubleshooting.
. Anv abnormality must be corrected before continuing the test.
. Because of the precise measurements needed, use a digital multimeter with an output of 1 mA or less at the 20 kO
range when testing.
. Before performing any troubleshooting procedures check:
- Fuses No. 47 17.5 AJ, No. 55 (40 A), No. 56 (20 A), No. 57 (20 A) in the under-hood fuse/relay box, and No. 17 {7.5 A) in
the under-dash fuse/relay box.._ Grounds No. G101, G201, G202, G401, G4O2
- Cleanliness and tightness of all connectors
SymptomSse pags
Mode control motor does not run, or one or more modes are inoperative.
Recirculation control door does not change between Fresh and Recirculate.22-24
Radiator fan does not run at all (but condenser fan runs with the AVC on).
Condenser fan does not run at all {but radiator fan runs with the Ay'C on).22-29
Both fans (radiator and condenser) do not run for engine cooling. but they both run with the A,/C
on.
Both fans do not run with the Ay'C on22-33
Compressor clutch does not engage.22-34
AJC svstem does not come on (both fans and compressor).22-37
Both heater and A/C do not work,22-39
22-10
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Relays
Test
There should be continuity between the No. 1 and No.3
terminals when power and ground are connected to the
No. 2 and No. 4 terminals, and there should be no conti-
nuity when power is disconnected.
3
o Blower motor relay
. Blower motor high relay
,I It)
In P
I)
There should be continuity between the No. 1 and No. 2
terminals when power and ground are connected to the
No. 3 and No. 4 terminals, and there should be no conti-
nuitv when oower is disconnected.
Rsdiator fan relay
Condenser fan relay
Compressor clutch relay
a
a
.I I
tr€
II
F)'"
,2-4.._.
22-45
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A/C System Service
Pressure Test Chart
NOTE: Performance Test is on page 22-56.
Test resultsRelatad symptomsPrcbable caus€Remody
Discharge (high)pressure 6bnormallyhagh
After stopping compressor, pressuredrops to about 200 kPa 12.0 kgtlcm,,28 psi) quickly, and then lalls gradualty.
Air in systemDischarge, evacuate, and rechargewith specified amount.Evacuation: see page 22-60Charging: see page 22-61No bubbles in sight glass whencondenser is cooled by waterExcessive refrigerant in systemDischarge, evacuate, and rechargewith specilied amount.Reduced or no air flow throughcondenser. Clogged condenser or radia-tor fins. Condenser or radiator fannot wo.king properly
CleanCheck voltage and fan rpm.Check fan direction.
Line to condensor is excossivelv hot.Restricted flow of relrigerant insy$emFestricted lines
Discharge pressureabnormally lowExcessive bubbles in sight glass;condenser is not hot.Insufficient retrigerant inCheck for leak.Charge system.High and low pressures are balancedsoon after stopping compressor. Lowside is higher than normal.
. Faulty compressor discharge
. Faulty compressor seal
Replace the comprossor.
Outlet ot expansion valve is notfrosted, low-pressure gauge indicates
' Faulty expansion valve. Moisture in system. Replace. Discharge, evacuate, andrecharge with specified amount.Suction {low) pros,sure abnormallyExcessive bubbles in sight glass;condenser is not hot.Insufficiont relrigerant inRepair the leaks.Discharge, evacuate, andrecharge with specified amount.Charge as r€quired.Expansion valve is not frosted, andlow-pressure line is not cold. Low-pressure gauge indicates vacuum.
' Frozen expansion valvelMoisture in system). Faulty expansion valve
. Discharge, evacuate, andrecharge with specitied amount.. Replace th€ expansion valve.Discharge temperature is low, and theair llow trom vents is restricted.Frozen evaporatorRun the fan with compressor off,then check evaporator tempera,ture sensor.Expansion valve is frosted.Clogged expansion valveClean or replace.Feceiver/dryer outlet is cool, and inlotrs w6rm (should be warm duringoperation).
Clogged receiver/dryerReplace
Suction pressureabnormally highLow-pressure hose and check joint arecooler than tho temperature aroundevaporator.
. Expansion valve open too long. Loose expansion capillarytube
Repair or roplace.
Suction pressure is lowored whencondenser is cooled by water.Excessive refrigerant in systemDischarge, evacuate, and rechargewath specified amount.High and low-pressure are equalizedas soon as tho compressor is stopped,and both gauges tluctuate whilerunning.
Faulty gasketFaulty high-pressure valveForeign panicle stuck in high-
Replace the compressor.
Slction and dis,charge pressutesabnormally high
Reduced air flow through condens€r,. Clogged condenser orradiator tins. Condenser or radiator fannot working properly
CleanCheck voltage and fan rpm.Check Ian direction.
No bubbles in sight glass whencondenser is cooled by walerExcessive refrigerant jn systemDischarge, evacuate, and rechargewith specified amount.Suction and dis-charge pressureabnormally low
Low-pressure hose and motalendareas are cooterlhan evaporator.Clogged or kinked low-pressure hose pansRepair or replace.
Temperature around expansion valvers too low compared with that aroundClogged high-pressure lineRepair or replace.
Refrigerant leaksCompressor clutch is diny.Compressor shaft seal leakingReplace the compressor.Compressor boltls) are dirty.Leaking around bolt(s)Tighton bolt{s) or replacecompressor.Compressor gasket is wet with oil.Gasket leakingReplace the compressor,
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