How to change the camshaft oil seals.

Here is a description on how to change camshaft oil seals on an Escort RS Cosworth, and the camshaft cover seal and halmoon seals.

It isn't difficult, just take your time and be accurate.

  1. Jack up the car and turn the wheels, or roll it forward/backwards so that the timing marks on the camshaft belt pulleys are facing each other. Put the car in gear and apply handbrake, and lower it to the ground. Recheck the timing marks.
  2. Remove cambelt cover. Loosen the bolts that holds the camshaft pulleys to the camshafts. If they are hard to undo use a hammer a bang the closed end wrench carefully so that they loosen. Let bolts sit on camshafts.
  3. Loosen the cambelt tensioning pulley.
  4. Remove the cam-belt from the camshaft pulleys, but not from the other pulleys.
  5. Unscrew all camshaft cover bolts and remove camshaft cover.
  6. Remove old camshaft cover seal and half-moon seals.
  7. Loosen the camshaft journal a little at a time, until all are loose, place the bolts and journals on a rug or paper in such a way that there is easy to get them back on in the same position and rotation as they were before.
  8. Remove one camshaft at a time, remove the bolt that holds the pulley to the camshaft, and the pulley from the camshaft, using a puller if necesary. Remove the old oil seal from the camshaft and note which way it sits on the camshaft. Clean front of camshaft, put some engine-oil on the new oil seal and put it onto the camshaft. Put the pulley back on and insert bolt. Put camshaft back onto cylinder head. Repeat with other camshaft.
  9. Tighten camshaft journals to specified torque starting at the front and working your way backwards. First just tighten them down, then torque them to the specified torque.
  10. Clean all gasket surfaces both on the camshaft cover, on the cylinder head and front camshaft journals.
  11. Put the cam cover gasket onto the cylinder head with some non-hardening gasket-compound under and over the gasket where it will join the half-moon seals. Put the half moon seal onto the front camshaft journals and apply gasket compound. Put the camshaft cover back onto the cylinder head ensuring that both the half moon seals and the camshaft cover seal lines up correctly.
  12. Put all the screws back into the camshaft cover and tighten it down starting at the middle and working your way outwards. Do this in two operations; first tighten all the bolts to about 3/4 the specified torque, then to the full torque specification.
  13. Align the camshaft pulleys so that the timing marks face each other, remove the distributor cap and check that the distributor arm is still at the TDC mark, check under the car that the crankshaft pulley TDC mark (an inward notch in the pulley) is also aligned with the mark on the cylinder block. When all alignments are correct put the cam belt back on and tighten the tensioning pulley and secure with the ecsentric.
  14. Jack car up and check that the engine turns freely without the valves interfering with the pistons.
  15. Turn the engine two full revolutions, check the tightness of the cambelt: On the longest stretch of the belt; between the crank pulley and the right hand pulley (as you look from the front) you should just about be able to twist the belt through 90 degrees. Ajust tightness, tighten the tensioner, rotate and double check.
  16. Put cambelt cover back on.

Recheck cambelt tension after your first short drive.

Tightening torques:

 Cam pulley to camshaft   59 - 63 Nm
 Cam cover to cylider head   10 - 15 Nm
 Camshaft bearing cap to cylinder head - M6   8 - 10 Nm
 Camshaft bearing cap to cylinder head - M8   19 - 23 Nm


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