Ford Taurus, Руководство пользователя

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1. Remove the cylinder head(s) and place on a clean surface.
2. Block the head on its side, or install a pair of head-holding brackets made
especially for valve removal.
3. Use a socket slightly larger than the valve stem and keepers, place the socket over
the valve stem and gently hit the socket with a plastic hammer to break loose any
varnish buildup.
4. Remove the valve keepers, retainer, spring shield and valve spring using a valve
spring compressor (the locking C-clamp type is the easiest kind to use).
5. Put the parts in a separate container numbered for the cylinder being worked on.
Do not mix them with other parts removed.
6. Remove and discard the valve stem oil seal, a new seal will be used at assembly
time.
7. Remove the valve from the cylinder head and place, in order, through numbered
holes punched in a stiff piece of cardboard or wooden valve holding stick.
The exhaust valve stems, on some engines, are equipped with small
metal caps. Take care not to lose the caps. Make sure to reinstall them at
assembly time. Replace any caps that are worn.
8. Use an electric drill and rotary wire brush to clean the intake and exhaust valve
ports, combustion chamber and valve seats. In some cases, the carbon will need
to be chipped away. Use a blunt pointed drift for carbon chipping, be careful
around the valve seat areas.
9. Use a wire valve guide cleaning brush and safe solvent to clean the valve guides.
10. Clean the valves with a revolving wire brush. Heavy carbon deposits may be
removed with the blunt drift.
When using a wire brush to clean carbon from the valve ports, valves,
etc., be sure that the deposits are actually removed, rather than
burnished.
11. Wash and clean all valve spring, keepers, retaining caps etc., in safe solvent.
12. Clean the head with a brush and some safe solvent and wipe dry.
13. Check the head for cracks. Cracks in the cylinder head usually start around an
exhaust valve seat because it is the hottest part of the combustion chamber. If a
crack is suspected but cannot be detected visually have the area checked with dye
penetrant or other method by a machine shop.
14. After all cylinder head parts are reasonably clean, check the valve stem-to-guide
clearance. If a dial indicator is not on hand, a visual inspection can give you a
fairly good idea if the guide, valve stem or both are worn.
15. Insert the valve into the guide until slightly away from the valve seat. Wiggle the
valve sideways. A small amount of wobble is normal, excessive wobble means a
worn guide or valve stem. If a dial indicator is on hand, mount the indicator so that
the stem of the valve is at 90° to the valve stem, as close to the valve guide as
possible. Move the valve off the seat, and measure the valve guide-to-stem
clearance by rocking the stem back and forth to actuate the dial indicator. Measure
the valve stem using a micrometer and compare to specifications to determine
whether stem or guide wear is causing excessive clearance.
16. The valve guide, if worn, must be repaired before the valve seats can be
resurfaced. Ford supplies valves with oversize stems to fit valve guides that are
reamed to oversize for repair. The machine shop will be able to handle the guide
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18.11.2005 file://C:\DOCUME~1\SILENT~1\LOCALS~1\Temp\trsHIPBC.htm