2001 TOYOTA PRIUS Service Repair Manual

A01168EM2548A01467
Front
Thrust
Direction
Axial
Direction
A10 mm
(0.39 in.)
B
C10 mm
(0.39 in.)
1
2
1
2
A01166
A01194
A12949
EM±72
± ENGINE MECHANICALCYLINDER BLOCK
2001 PRIUS (RM778U)
5. INSPECT CYLINDER BORE DIAMETER
Using a cylinder gauge, measure the cylinder bore diameter at
positions A, B and C in the thrust and axial directions.
Standard diameter:
75.000 ± 75.013 mm (2.95275 ± 2.95326 in.)
Maximum diameter:
75.013 mm (2.95326 in.)
If the diameter is greater than maximum, replace the cylinder
block.
6. REMOVE CYLINDER RIDGE
If the wear is less than 0.2 mm (0.008 in,), using a ridge reamer,
grind the top of the cylinder.
7. INSPECT 12 POINTED HEAD BEARING CAP SUB±
ASSEMBLY BOLTS
Using vernier calipers, measure the tension portion diameter of
the bolt.
Standard diameter: 7.3 ± 7.5 mm (0.287 ± 0.295 in.)
Minimum diameter: 7.3 mm (0.287 in.)
If the diameter is less than minimum, replace the bolt.
8. CLEAN PISTON
(a) Using a gasket scraper, remove the carbon from the pis-
ton top.

A12950
A12951
A1295227 mm
A12953
± ENGINE MECHANICALCYLINDER BLOCK
EM±73
2001 PRIUS (RM778U)
(b) Using a groove cleaning tool or broken ring, clean the pis-
ton ring grooves.
(c) Using solvent and a brush, thoroughly clean the piston.
NOTICE:
Do not use a wire brush.
9. INSPECT PISTON OIL CLEARANCE
(a) Using a micrometer, while placing the piston up side
down, take measurement at the position of 27 mm (1.06
in.).
Piston diameter:
74.930 ± 74.940 mm (2.94999 ± 2.95039 in.)
(b) Measure the cylinder bore diameter in the thrust direc-
tions. (See procedure in step 5)
(c) Subtract the piston diameter measurement from the cylin-
der bore diameter measurement.
Standard oil clearance:
0.045 ± 0.068 mm (0.00177 ± 0.00268 in.)
Maximum oil clearance:
0.095 mm (0.0037 in.)
If the oil clearance is greater than maximum, replace all the 4
pistons. If necessary, replace the cylinder block.
10. INSPECT PISTON RING END GAP
Using a feeler gauge, measure the clearance between new pis-
ton ring and the wall of the ring groove.
Ring groove clearance:
0.030 ± 0.070 mm (0.0012 ± 0.0028 in.)
If the clearance is not as specified, replace the piston.

A12954
11 0
mm
EM7639
Z00064
Z00065
A01185
EM±74
± ENGINE MECHANICALCYLINDER BLOCK
2001 PRIUS (RM778U)
11. INSPECT PISTON RING END GAP
(a) Insert the piston ring into the cylinder bore.
(b) Using a piston, push the piston ring a little beyond the bot-
tom of the ring travel, 110 mm (4.33 in.) from the top of the
cylinder block.
(c) Using a feeler gauge, measure the end gap.
Standard end gap:
No. 1 0.22 ± 0.32 mm (0.0087 ± 0.0126 in.)
No. 2 0.32 ± 0.47 mm (0.0126 ± 0.0185 in.)
Oil (Side rail) 0.15 ± 0.45 mm (0.0059 ± 0.0177 in.)
Maximum end gap:
No. 1 0.88 mm (0.0346 in.)
No. 2 1.03 mm (0.0406 in.)
Oil 0.92 mm (0.0362 in.)
If the end gap is greater than maximum, replace the piston ring.
If the end gap is greater than maximum, even with a new piston
ring, replace the cylinder block.
12. INSPECT CONNECTING ROD ALIGNMENT
Using a rod aligner and feeler gauge, check the connecting rod
alignment.

Check for out±of±alignment
Maximum out±of alignment:
0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
If out±of alignment is greater than maximum, replace the con-
necting rod assembly.

Check for twist
Maximum twist:
0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
If twist is greater than maximum, replace the connecting rod as-
sembly.
13. INSPECT PISTON PIN OIL CLEARANCE
(a) Using a caliper gauge, measure the inside diameter of the
connecting rod bushing.
Bushing inside diameter:
18.010 ± 18.019 mm (0.7091 ± 0.7094 in.)

EM0227
A01470
A11241
± ENGINE MECHANICALCYLINDER BLOCK
EM±75
2001 PRIUS (RM778U)
(b) Using a micrometer, measure the piston pin diameter.
Piston pin diameter:
17.988 ± 18.007 mm (0.7086 ± 0.7089 in.)
(c) Subtract the piston pin diameter measurement from the
bushing inside diameter measurement.
Standard oil clearance:
0.009 ± 0.015 mm (0.0003 ± 0.0006 in.)
Maximum oil clearance:
0.05 mm (0.0020 in.)
If the oil clearance is greater than maximum, replace the con-
necting rod. If necessary, replace the piston and piston pin as
a set.
14. INSPECT CONNECTING ROD BOLTS
Using a vernier calipers, measure the tension portion diameter
of the bolt.
Standard diameter: 6.6 ± 6.7 mm (0.260 ± 0.264 in.)
Minimum diameter: 6.4 mm (0.252 in.)
If the diameter is less than minimum, replace the bolt.
15. INSPECT CRANKSHAFT FOR CIRCLE RUNOUT
(a) Place the crankshaft on V±blocks.
(b) Using a dial indicator, measure the circle runout, as
shown in the illustration.
Maximum circle runout: 0.03 mm (0.0012 in.)
If the circle runout is greater than maximum, replace the crank-
shaft.