a. Ball Travel

Immediately after the lifter parts have been cleaned and inspected (See Sections 6 and 7) check the ball travel on Test Fixture J 5095 as follows:

  1. Use Sleeve KM0-30-K to mount Dial Indicator KM0-30-B so that stem of indicator bears squarely on upper end of the pin in ball travel checking attachment of the test fixture. See Figure 17.
    1951 Buick Checking Hydraulic Valve Lifters Ball Travel

    1951 Buick Checking Hydraulic Valve Lifters Ball Travel

  2. Select a new ball and place it in the seat on plunger, then hold plunger and ball firmly against under side of the attachment arm with plunger centered over the pin and stepped flange. See Figure 17, view A.
  3. While holding ball and plunger firmly in place, set the dial indicator needle at “0” (zero).
  4. Remove plunger and ball, place ball in ball retainer, and install these parts on plunger.
  5. Center the plunger over the pin and stepped flange of the check attachment and while pressing plunger and retainer firmly against attachment arm note the dial indicator reading. See Figure 17, view B.
  6. The dial indicator reading shows the distance that the ball can travel from its seat until stopped by the retainer. The ball travel must be .004″ to .008″ to insure satisfactory lifter operation.
  7. If ball travel is not within the specified limits use a new ball retainer and repeat steps 4 and 5. It may be necessary to try several new retainers to select one that provides the required ball travel with the particular plunger and ball.

Too much ball travel will allow more oil to flow from the lifter lower chamber just before the ball seats, causing excess lash in the valve linkage. Insufficient ball travel will cause the volume of oil in the lower chamber to increase or “pump up”, thereby preventing the engine valve from seating

b. Leakdown

After a valve lifter has been cleaned, inspected, checked for ball travel, and assembled it must be tested for leakdown rate before it is installed in an engine. In Section 1, d, leakdown was defined to be the leakage of oil from the lifter lower chamber through the clearance between body and plunger, during opening and closing of the engine valve.

Lifter Test Fixture J-5095 has been designed to test the leakdown rate of a lifter to determine whether it is within limits which assure satisfactory lifter operation. The following procedure must be carefully followed to obtain an accurate test.

  1. Prepare a special test fluid by placing 12 ounces of SAE 10 engine oil in a CLEAN and accurate one gallon container, fill container to the one gallon mark with kerosene, then stir or shake the container to thoroughly mix the oil and kerosene. NOTE: A Coca-Cola bottle (capacity 6 oz.) makes a convenient measure for the oil. A one gallon glass jug makes a convenient container for the fluid.
  2. Thoroughly clean the cup of test fixture then set it in place and fill to within 1/2″ of the top.
  3. Swing the weight arm up out of the way, resting it against the top end of its support.
  4. Raise the ram and install the valve lifter in the cup of fluid, making sure that it seats squarely on the rubber disc in the recess at bottom of cup. The lifter must be completely covered by the fluid in cup at all times.
  5. Lower the ram to rest in the lifter push rod seat, then lower the weight arm to rest on the roller of ram.