TOYOTA PRIUS 2001 Service Repair Manual

A01076
EM16K±03
A01077
A01068
A01069
A01070
± ENGINE MECHANICALCYLINDER HEAD
EM±33
2001 PRIUS (RM778U)
INSPECTION
1. CLEAN TOP SURFACES OF PISTONS AND CYL-
INDER BLOCK
(a) Turn the crankshaft, and bring each piston to top dead
center (TDC). Using a gasket scraper, remove all the car-
bon from the piston surface.
(b) Using a gasket scraper, remove all the gasket material
from the cylinder block surface.
(c) Using compressed air, blow carbon and oil from the bolt
holes.
CAUTION:
Protect your eyes when using high pressure compressed
air.
2. REMOVE GASKET MATERIAL
Using a gasket scraper, remove all the gasket material from the
cylinder block contact surface.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.
3. CLEAN COMBUSTION CHAMBERS
Using a wire brush, remove all the carbon from the combustion
chambers.
NOTICE:
Be careful not to scratch the cylinder block contact sur-
face.
4. CLEAN CYLINDER HEAD
Using a soft brush and solvent, thoroughly clean the cylinder
head.

A01479
A01075
Cylinder Block Side
Intake Manifold Side
Exhaust Manifold Side
A01071
EM0580
EM±34
± ENGINE MECHANICALCYLINDER HEAD
2001 PRIUS (RM778U)
5. CLEAN VALVE GUIDE BUSHINGS
Using a valve guide bushing brush and solvent, clean all the
guide bushings.
6. INSPECT FOR FLATNESS
Using a precision straight edge and feeler gauge, measure the
surface contacting the cylinder block and the manifolds for war-
page.
Maximum warpage:
Cylinder block side0.05 mm (0.0020 in.)
Intake Manifold side0.10 mm (0.0394 in.)
Exhaust manifold side0.10 mm (0.0394 in.)
If warpage is greater than maximum, replace the cylinder head.
7. INSPECT FOR CRACKS
Using a dye penetrant, check the combustion chamber, intake
ports, exhaust ports and cylinder block surface for cracks.
If cracked, replace the cylinder head.
8. CLEAN VALVES
(a) Using a gasket scraper, chip off any carbon from the valve
head.
(b) Using a wire brush, thoroughly clean the valve.

A01478
Z00052
EM0180
44.5°
EM0181
Margin Thickness
± ENGINE MECHANICALCYLINDER HEAD
EM±35
2001 PRIUS (RM778U)
9. INSPECT VALVE STEMS AND GUIDE BUSHINGS
(a) Using a caliper gauge, measure the inside diameter of the
guide bushing.
Bushing inside diameter:
5.010 ± 5.030 mm (0.19724 ± 0.19803 in.)
(b) Using a micrometer, measure the diameter of the valve
stem.
Valve stem diameter:
Intake 4.970 ± 4.985 mm (0.19567 ± 0.19626 in.)
Exhaust 4.965 ± 4.980 mm (0.19547 ± 0.19606 in.)
(c) Subtract the valve stem diameter measurement from the
guide bushing inside diameter measurement.
Standard oil clearance:
Intake 0.025 ± 0.060 mm (0.00098 ± 0.00236 in.)
Exhaust 0.030 ± 0.065 mm (0.00118 ± 0.00256 in.)
Maximum oil clearance:
Intake 0.08 mm (0.0031 in.)
Exhaust 0.10 mm (0.0039 in.)
If the clearance is greater than maximum, replace the valve and
guide bushing.
10. INSPECT VALVES
(a) Check the valve is ground to the correct valve face angle.
Valve face angle: 44.5°
(b) Check that the surface of the valve for wear.
If the valve face is worn, replace the valve.
(c) Check the valve head margin thickness.
Standard margin thickness:
1.00 ± 1.15 mm (0.0393 ± 0.0453 in.)
Minimum margin thickness: 0.7 mm (0.028 in.)
If the margin thickness is less than minimum, replace the valve.

EM2534
Overall Length
A01073
45° Carbide
CutterResiduary
Width
Resurface
A01074
Width
EM0185
45°20°
1.0 ± 1.4 mm
EM0186
75°
1.0 ± 1.4 mm45°
EM±36
± ENGINE MECHANICALCYLINDER HEAD
2001 PRIUS (RM778U)
(d) Check the valve overall length.
Standard overall length:
Intake 89.25 mm (3.5138 in.)
Exhaust 87.90 mm (3.4606 in.)
Minimum overall length:
Intake 88.95 mm (3.5020 in.)
Exhaust 87.60 mm (3.4488 in.)
If the overall length is less than minimum, replace the valve.
(e) Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, replace the valve.
11. INSPECT AND CLEAN VALVE SEATS
(a) Using a 45° carbide cutter, resurface the valve seats.
Remove only enough metal to clean the seats.
(b) Check the valve seating position.
Apply a light coat of prussian blue (or white lead) to the
valve face. Lightly press the valve against the seat. Do not
rotate valve.
(c) Check the valve face and seat for the following:

If blue appears 360° around the face, the valve is
concentric. If not, replace the valve.

If blue appears 360° around the valve seat, the
guide and face are concentric. If not, resurface the
seat.

Check that the seat contact is in the middle of the
valve face with the following width:
1.0 ± 1.4 mm (0.039 ± 0.055 in.)
If not, correct the valve seats as follows:
(1) If the seating is too high on the valve face, use 20°
and 45° cutters to correct the seat.
(2) If the seating is too low on the valve face, use 75°
and 45° cutters to correct the seat.

A01072
EM0988
Deviation
EM0801
EM0281
EM1628
± ENGINE MECHANICALCYLINDER HEAD
EM±37
2001 PRIUS (RM778U)
(d) Hand±lap the valve and valve seat with an abrasive com-
pound.
(e) After hand±lapping, clean the valve and valve seat.
12. INSPECT VALVE SPRINGS
(a) Using a steel square, measure the deviation of the valve
spring.
Maximum deviation: 1.6 mm (0.063 in.)
Maximum angle (reference): 2°
If the deviation is greater than maximum, replace the valve
spring.
(b) Using vernier calipers, measure the free length of the
valve spring.
Free length: 59.77 mm (2.353 in.)
If the free length is not as specified, replace the valve spring.
(c) Using a spring tester, measure the tension of the valve
spring at the specified installed length.
Installed tension:
140 ± 154 N (14.3 ± 15.7 kgf, 31.5 ± 34.6 lbf)
at 32.5 mm (1.280 in.)
Maximum working tension:
180 ± 198 N (18.4 ± 20.2 kgf, 40.4 ± 44.8 lbf)
at 25.1 mm (0.988 in.)
If the installed tension is not as specified, replace the valve
spring
13. INSPECT CAMSHAFT FOR RUNOUT
(a) Place the camshaft on V±blocks.
(b) Using a dial indicator, measure the circle runout at the
center journal.
Maximum circle runout: 0.03 mm (0.0012 in.)
If the circle runout is greater than maximum, replace the cam-
shaft.

EM2011
EM2538
A01452
Plastigage
A12943
A01453
EM±38
± ENGINE MECHANICALCYLINDER HEAD
2001 PRIUS (RM778U)
14. INSPECT CAM LOBES
Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
Intake 42.310 ± 42.410 mm (1.62637 ± 1.66968 in.)
Exhaust 44.046 ± 44.146 mm (1.73409 ± 1.73803 in.)
Minimum cam lobe height:
Intake 42.16 mm (1.6598 in.)
Exhaust 43.90 mm (1.7283 in.)
If the cam lobe height is less than minimum, replace the cam-
shaft.
15. INSPECT CAMSHAFT JOURNALS
Using a micrometer, measure the journal diameter.
No.1 journal diameter:
34.449 ± 34.465 mm (1.35626 ± 1.35689 in.)
Others journal diameter:
22.949 ± 22.965 mm (0.90350 ± 0.90413 in.)
If the journal diameter is not as specified, check the oil clear-
ance.
16. INSPECT CAMSHAFT JOURNAL CLEARANCE
(a) Clean the bearing caps and camshaft journals.
(b) Place the camshafts on the cylinder head.
(c) Lay a strip of Plastigage across each of the camshaft jour-
nal.
(d) Install the bearing caps (See page EM±45).
Torque:
No.1 23 N´m (235 kgf´cm, 17 ft´lbf)
No.2 12.7 N´m (130 kgf´cm, 10 ft´lbf)
NOTICE:
Do not turn the camshaft.
(e) Remove the bearing caps.
(f) Measure the plastigage at its widest point.
Standard oil clearance:
0.040 ± 0.095 mm (0.00157 ± 0.00374 in.)
Maximum oil clearance:
0.115 mm (0.00453 in.)
If the oil clearance is greater than maximum, replace the cam-
shaft. If necessary, replace the bearing caps and cylinder head
as a set.
(g) Completely remove the Plastigage.
(h) Remove the camshafts.

A01455
A13949
P16860
± ENGINE MECHANICALCYLINDER HEAD
EM±39
2001 PRIUS (RM778U)
17. INSPECT CAMSHAFT THRUST CLEARANCE
(a) Install the camshafts (See page EM±45).
(b) Using a dial indicator, measure the thrust clearance while
moving the camshaft back and forth.
Standard thrust clearance:
0.040 ± 0.095 mm (0.0016 ± 0.0037 in.)
Maximum thrust clearance:
0.11 mm (0.0043 in.)
If the thrust clearance is greater than maximum, replace the
camshaft. If necessary, replace the bearing caps and cylinder
head as a set.
(c) Remove the camshafts.
18. INSPECT VALVE LIFTERS AND LIFTER BORES
(a) Using a caliper gauge, measure the lifter bore diameter
of the cylinder head.
Lifter bore diameter:
31.009 ± 31.025 mm (1.22082 ± 1.22145 in.)
(b) Using a micrometer, measure the lifter diameter.
Lifter diameter:
30.966 ± 30.976 mm (1.21913 ± 1.21953 in.)
(c) Subtract the lifter diameter measurement from the lifter
bore diameter measurement.
Standard oil clearance:
0.031 ± 0.059 mm (0.00122 ± 0.00232 in.)
Maximum oil clearance:
0.1 mm (0.004 in.)
If the oil clearance is greater than maximum, replace the lifter.
If necessary, replace the cylinder head.

A13936
A13937
EM±40
± ENGINE MECHANICALCYLINDER HEAD
2001 PRIUS (RM778U)
19. INSPECT INTAKE MANIFOLD
Using a precision straight edge and feeler gauge, measure the
surface contacting the cylinder head for warpage.
Maximum warpage: 0.10 mm (0.0039 in.)
If warpage is greater than maximum, replace the manifold.
20. INSPECT EXHAUST MANIFOLD
Using a precision straight edge and feeler gauge, measure the
surface contacting the cylinder head for warpage.
Maximum warpage: 0.70 mm (0.0276 in.)
If warpage is greater than maximum, replace the manifold.

A01067
80 ± 100°C
EM16L±02
A01066
SST
A13949
Both intake and exhaust
Bushing bore diameter
mm (in.)Bushing size
9.685 ± 9.706
(0.38130 ± 0.38213)Use STD
9.735 ± 9.756
(0.38327 ± 0.38493)Use O/S 0.05
A01446
SST
± ENGINE MECHANICALCYLINDER HEAD
EM±41
2001 PRIUS (RM778U)
REPLACEMENT
REPLACE VALVE GUIDE BUSHINGS
(a) Gradually heat the cylinder head to 80 ± 100°C (176 ±
212°F).
(b) Using SST and a hammer, tap out the guide bushing.
SST 09201±01055, 09950±70010 (09951±07100)
(c) Using a caliper gauge, measure the bushing bore diame-
ter of the cylinder head.
(d) Select the new guide bushing (STD or O/S 0.05).
If the bushing bore diameter of the cylinder head is greater than
9.706 mm (0.38213 in.), machine the bushing bore to the fol-
lowing dimension:
9.735 ± 9.756 mm (0.38327 ± 0.38493 in.)
If the bushing bore diameter of the cylinder head is greater than
9.756 mm (0.38493 in.), replace the cylinder head.
(e) Gradually heat the cylinder head to 80 ± 100°C (176 ±
212°F).
(f) Using SST and a hammer, tap in a new guide bushing to
the specified protrusion height.
SST 09201±01055, 09950±70010 (09951±07100)
Protrusion height:
9.0 ± 9.4 mm (0.354 ± 0.370 in.)

A01447
EM±42
± ENGINE MECHANICALCYLINDER HEAD
2001 PRIUS (RM778U)
(g) Using a sharp 5 mm reamer, ream the guide bushing to
obtain the standard specified clearance (See page
EM±33) between the guide bushing and valve stem.