YH4
GRAND
VITARA
1B-8 AIR CONDITIONING (OPTIONAL)
DIAGNOSIS OF ABNORMAL NOISE
There are various types of noise, ranging from those produced in the engine compartment to those from the pas-
senger compartment, also from rumbling noises to whistling noises.
ABNORMAL NOISE FROM COMPRESSOR
ConditionPossible CauseCorrection
During compressor operation, a
rumbling noise is heard
proportional to engine
revolutions.Inadequate clearance in piston
area (piston or swash-plate).Repair or replace compressor as
necessary.
A loud noise is heard at a certain
rpm, disproportionately to engine
revolution.Loose or faulty V-belt.
Loose mounting bolts.Adjust V-belt tension, or
replace belt.
Retighten mounting bolts.
A loud rattle is heard at low
engine rpm.Loose compressor center bolt.Retighten center bolt.
Replace compressor if it was
operated in this condition for a
long time.
ABNORMAL NOISE FROM MAGNETIC CLUTCH
ConditionPossible CauseCorrection
A rumbling noise is heard when
compressor is not operating.Worn or damaged bearings.Replace bearings.
A chattering noise is heard when
compressor is engaged.Faulty clutch gap (excessive).
Worn clutch friction surface.
Compressor oil leaked from shaft
seal, contaminating the friction
surface.Adjust clutch gap.
Replace clutch.
Replace compressor shaft oil
seal.
ABNORMAL NOISE FROM TUBING
ConditionPossible CauseCorrection
A droning noise is heard inside
vehicle, but not particularly
noticeable in engine
compartment.Faulty tubing clamps.
Resonance caused by pulsation
from variations in refrigerant
pressure.Reposition clamps or increase
the number of clamps.
Attach a silencer to tubing, or
modify its position and length.
ABNORMAL NOISE FROM CONDENSER
ConditionPossible CauseCorrection
Considerable vibration in
condenser.Resonance from condenser
mounting stay and body.Firmly insert a silencer between
condenser mounting stay and
body.
YH4
GRAND
VITARA
[FOR VEHICLE WITHOUT ABS]
[FOR VEHICLE WITH ABS]
1. Master cylinder
2-1. 4-way joint
2-2. 2-way joint
3. LSPV (Load Sensing Proportioning Valve)
4. Rear axle housing
5. ABS actuator (H.U.)
F.R.:Front side
5-2 BRAKES
GENERAL DESCRIPTION
When the foot brake pedal is depressed, hydraulic pressure is developed in the master cylinder to actuate pistons
(two in front and four in rear).
The master cylinder is a tandem master cylinder. Brake pipes are connected to the master cylinder and they make
two independent circuits. One connects front brakes (right and left) and the other connects rear brakes (right and
left).
The load sensing proportioning valve (LSPV) is included in these circuits between the master cylinder and the rear
brake for the vehicle without ABS.
In this brake system, the disc brake type is used for the front wheel brake and a drum brake type (leading / trailing
shoes) for the rear brake.
The parking brake system is mechanical. It applies brake force to only rear wheels by means of the cable and me-
chanical linkage system. The same brake shoes are used for both parking and foot brakes.
YH4
GRAND
VITARA
BRAKES 5-3
SUBSTANDARD OR
CONTAMINATED BRAKE FLUID
Improper brake fluid, mineral oil or water in the fluid
may cause the brake fluid to boil or the rubber compo-
nents in the hydraulic system to deteriorate.
If primary piston cups are swollen, then rubber parts
have deteriorated. This deterioration may also be evi-
denced by swollen wheel cylinder piston cups on the
drum brake wheels.
If deterioration of rubber is evident, disassemble all
hydraulic parts and wash with alcohol. Dry these parts
with compressed air before assembly to keep alcohol
out of the system. Replace all rubber parts in the sys-
tem, including hoses. Also, when working on the
brake mechanisms, check for fluid on the linings. If ex-
cessive fluid is found, replace the linings.
If master cylinder piston seals are satisfactory, check
for leakage or excessive heat conditions. If condition
is not found, drain fluid, flush with brake fluid, refill and
bleed system.
The system must be flushed if there is any doubt as
to the grade of fluid in the system or if fluid has been
used which contained parts that have been subjected
to contaminated fluid.
DIAGNOSIS
ROAD TESTING BRAKES
Brakes should be tested on dry, clean, smooth and
reasonably level roadway which is not crowned. Road
test brakes by making brake applications with both
light and heavy pedal forces at various speeds to de-
termine if the vehicle stops evenly and effectively.
Also drive vehicle to see if it leads to one side or the
other without brake application. If it does, check the
tire pressure, front end alignment and front suspen-
sion attachments for looseness. See diagnosis chart
for other causes.
BRAKE FLUID LEAKS
Check the master cylinder fluid levels. While a slight
drop in reservoir level does result from normal lining
wear, an abnormally low level indicates a leak in the
system. In such a case, check the entire brake system
for leakage. If even a slight evidence of leakage is
noted, the cause should be corrected or defective
parts should be replaced.
If fluid level is lower than the minimum level of reser-
voir, refilling is necessary. Fill reservoir with specified
brake fluid.
Brake fluid: Refer to reservoir tank cap.
CAUTION:
Since brake system of this vehicle is factory-
filled with brake fluid indicated on reservoir
tank cap, do not use or mix different type of
fluid when refilling; otherwise serious damage
will occur.
Do not use old or used brake fluid, or any fluid
from a unsealed container.
YH4
GRAND
VITARA
5-4 BRAKES
DIAGNOSIS TABLE
ConditionPossible CauseCorrection
Not enough brak-
ing forceBrake oil leakage from brake lines.
Brake disc or pads stained with oil.
Overheated brakes.
Poor contact of shoes on brake drum.
Brake shoes linings stained with oil or wet
with water.
Badly worn brake shoe linings.
Defective wheel cylinders.
Malfunctioning caliper assembly.
Air in system.
Maladjusted sensor spring length of LSPV.
Broken sensor spring of LSPV.
Defective collar of LSPV.
Malfunctioning ABS (Antilock brake system),
if equipped.Locate leaking point and repair.
Clean or replace.
Determine cause and repair.
Repair for proper contact.
Replace.
Replace.
Repair or replace.
Repair or replace.
Bleed system.
Check or adjust.
Replace.
Replace.
Check system and replace as
necessary.
Brake pull
(Brakes not work-
ing in unison)Pad or shoe linings are wet with water or
stained with oil in some brakes.
Drum-to-shoe clearance out of adjustment in
some brakes.
(Malfunctioning auto adjusting mechanism)
Drum is out of round in some brakes.
Wheel tires are inflated unequally.
Malfunctioning wheel cylinders.
Disturbed front end alignment.
Unmatched tires on same axle.
Restricted brake pipes or hoses.
Malfunctioning caliper assembly.
Loose suspension parts.
Loose calipers.Replace.
Check for inoperative auto adjusting
mechanism.
Replace.
Inflate equally.
Repair or replace.
Adjust as prescribed.
Tires with approximately the same
amount of tread should be used on the
same axle.
Check for soft hoses and damaged
lines.
Replace with new hoses and new
brake pipes.
Check for stuck or sluggish pistons
and proper lubrication of caliper slide
bush.
Caliper should slide.
Check all suspension mountings.
Check and torque bolts to specifica-
tions.
Noise (High pitched
squeak without
brake applied)Front lining worn out.Replace linings.
Rear brake locked
prematurelyMaladjusted sensor spring length of LSPV.
Malfunction LSPV assembly.Check or adjust.
Replace assembly.
Brake locked
(For vehicles
equipped with
ABS)Malfunctioning ABS, if equipped.Check system and replace as
necessary.
YH4
GRAND
VITARA
BRAKES 5-5
ConditionPossible CauseCorrection
Excessive pedal
travel (Pedal
stroke too large)Partial brake system failure.
Insufficient fluid in master cylinder
reservoirs.
Air in system. (pedal soft / spongy)
Rear brake system not adjusted.
(malfunctioning auto adjusting mechanism)
Bent brake shoes.
Worn rear brake shoes.Check brake systems and repair as
necessary.
Fill reservoirs with approved brake
fluid.
Check for leaks and air in brake
systems.
Check warning light. Bleed system if
required.
Bleed system.
Repair auto adjusting mechanism.
Adjust rear brakes.
Replace brake shoes.
Replace brake shoes.
Dragging brakes
(A very light drag
is present in all
disc brakes
immediately
after pedal is
released)Master cylinder pistons not returning
correctly.
Restricted brake pipes or hoses.
Incorrect parking brake adjustment on rear
brakes.
Weakened or broken return springs in the
brake.
Sluggish parking-brake cables or linkage.
Wheel cylinder or caliper piston sticking.
Malfunctioning ABS, if equipped with ABS.Replace master cylinder.
Check for soft hoses or damaged
pipes and replace with new hoses
and / or new brake pipes.
Check and adjust to correct specifi-
cations.
Replace.
Repair or replace.
Repair as necessary.
Check system and replace as
necessary.
Pedal pulsation
(Pedal pulsates
when depressed
for braking)Damaged or loose wheel bearings.
Distorted steering knuckle or rear axle
shafts.
Excessive disc lateral runout.
Parallelism not within specifications.
Rear drums out of round.Replace wheel hub component.
Replace knuckle or rear axle shaft.
Check per instructions. If not within
specifications, replace or machine
the disc.
Check per instructions. If not within
specifications, replace or machine
the disc.
Check runout.
Repair or replace drum as
necessary.
Braking noiseGlazed shoe linings, or foreign matters
stuck to linings.
Worn or distorted shoe linings.
Loose front wheel bearings.
Distorted backing plates or loose mounting
bolts.Repair or replace shoe lining.
Replace shoe lining (or pad).
Replace wheel hub component.
Replace or retighten securing bolts.
YH4
GRAND
VITARA
[A]: With ABS
[B]: Without ABS
1. Piston stopper circlip
2. Piston stopper
3. Cylinder cup
4. Plate
5. Primary piston
6. Piston cup
7. Primary piston return spring
8. Primary spring retainer
9. Secondary piston pressure cup
10. Secondary piston
11. Return spring secondary seat
12. Secondary piston return spring
13. Secondary piston stopper bolt
14. Master cylinder body
ªAº: Primary piston
ªBº: Secondary piston
[B] [A]
5A-2 BRAKES PIPE / HOSE / MASTER CYLINDER
GENERAL DESCRIPTION
MASTER CYLINDER ASSEMBLY
The master cylinder has two pistons and three piston cups. Its hydraulic pressure is produced in the primary (ªaº
in the figure below) and secondary (ªbº) chambers. The hydraulic pressure produced in the primary chamber (ªaº)
acts on the front (for vehicle without ABS, rear) wheel brakes.
Also, the hydraulic pressure produced in the secondary chamber (ªbº) acts on the rear (for vehicle without ABS,
front) wheel brakes.
NOTE:
Replace all components included in repair kits to service this master cylinder. Lubricate rubber parts with
clean, fresh brake fluid to ease assembly. Do not use lubricated shop air on brake parts as damage to rub-
ber components may result. If any hydraulic component is removed or brake line disconnected, bleed the
brake system.
The torque values specified are for dry, unlubricated fasteners.
BOOSTER ASSEMBLY
The booster is located between the master cylinder and the brake pedal. It is so designed that the force created
when the brake pedal is depressed is mechanically increased combined with the engine vacuum.
The booster has two diaphragms of
ù7.5 in. (191 mm) effective diameter.
CAUTION:
Never disassemble brake booster assembly. If it is found faulty, replace it with new assembly.
The torque values specified are for dry, unlubricated fasteners. If any hydraulic component is re-
moved or brake line disconnected, bleed the brake system.
YH4
GRAND
VITARA
1. LSPV
2. LSPV lever
3. Spring
4. LSPV stay
5. Brake flare nut
[A]: Type A
[B]: Type B
1. Plunger
2. Lip seal
3. LSPV lever
4. Sensor spring
5. From master cylinder
primary chamber
(Rear wheel brake)
6. From master cylinder
secondary chamber
(Front wheel brake)
7. To rear wheel brake
8. Pin
9. Bolt hole
[A] [B]
44
BRAKES PIPE / HOSE / MASTER CYLINDER 5A-3
LSPV (Load Sensing Proportioning Valve) ASSEMBLY (if equipped)
As shown in figure below, LSPV is included within the brake circuit which connects the master cylinder and the rear
wheel brake. It controls the hydraulic pressure applied to the rear wheel brake according to the loaded state of the
vehicle (or weight of the load), whereby preventing the rear wheels from getting locked prematurely.
Also, it releases the above described control over the hydraulic pressure applied to the rear wheel brake, should
any failure occur in the hydraulic circuit of the front wheel brake so that the hydraulic pressure produced in the mas-
ter cylinder is applied to the rear wheel brake directly to operate it.
CONSTITUTION
The LSPV components are grouped into three sections as follows.
ªAº: Sensor section
The main parts in this section are a lever and a spring which senses variation in the vehicle height as affected
by the loaded condition and converts it into the load.
ªBº: Hydraulic pressure control section
Included in this section are a stepped plunger and valve mechanism to execute proportional control.
ªCº: Fail-safe section
The main parts in this section are a chamber which draws in the hydraulic pressure from the front wheel brake
system and a fail-safe piston which releases the valve mechanism in the control section connected to the rear
wheel brake, should any failure occur in the front wheel brake system.
YH4
GRAND
VITARA
4
3
1. Piston stopper circlip
2. Piston stopper
3. Cylinder cup and plate
4. Primary piston
5. Piston cup
6. Secondary piston pressure cup
7. Primary piston Assy
8. Secondary piston
9. Secondary piston Assy
10. Secondary piston stopper bolt
11. Master cylinder body
12. O-ring
[A] [B]
[A]: With ABS
[B]: Without ABS
5. Attaching nut
6. ABS control module
connector
7. Bracket bolt 1. Reservoir cap
2. Reservoir
3. Master cylinder
4. Flare nuts
5A-10 BRAKES PIPE / HOSE / MASTER CYLINDER
MASTER CYLINDER ASSEMBLY
REMOVAL
NOTE:
Do not allow brake fluid to get on painted surfaces.
1) Disconnect reservoir lead wire at coupler.
2) Clean around reservoir cap and take out fluid with syringe or
such.
3) Remove master cylinder with reservoir from brake booster.
For vehicle with ABS
a) Loosen flare nuts for master cylinder and ABS hydraulic
unit as shown.
b) For LH steering vehicle, disconnect ABS control module
connector.
c) For RH steering vehicle, remove ABS hydraulic unit brack-
et bolts.
d) Disconnect brake pipes between master cylinder and ABS
hydraulic unit.
For vehicle without ABS
a) Loosen flare nuts for master cylinder.
b) Disconnect brake pipes for master cylinder.