Hydraulic Tappets

By Dennis Santopietro

Q: I wonder if you can help me on a topic.
Is there any information on stripping, rebuilding and priming standard hydraulic tappets on a twin cam 88?
I can’t find anything online about this.
I have stripped them and put them back together again, no problem.
I just wondered if I needed to fill them with oil before I rebuilt them or if it’s ok to just coat the insides with oil and leave them empty
(ie, do they fill themselves when the engine is started, or do the need to be primed in a particular way).
Any help on this would be great.
I look forward to hearing back from you.
Kind regards
Charles G

A:There is no need to prime the lifters before installation. It is important to re assemble them with assembly lube, or clean 20/50 wt oil; as you had mentioned. When you 1st start the m/c, do not rev it. Give the lifters a chance to bleed up. If you hear a little “ticking”, pay attention to it, but do not be overly alarmed. Some lifters take longer than others to bleed up. Thanks, and good luck.

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5 Responses to “Hydraulic Tappets”

  1. Frank Colistro

    That's exactly been my experience.

  2. Charles plaisted

    Adjusting hydraulic pushrods on the twin cam is it the same as hydraulic pushrods on a shovel

  3. Tom Murphy

    I have a 88 bored to a 96, that when it is 90 degrees out the lifters and push rods make alot of chatter, I had a sportster that did this too, any suggestions?

  4. Ron

    When I first start up the 97 ultra classic the lifters slap for a bit , and when I take off the lifters make some more noise. And once in awhile in other gears?

  5. RayJPav

    <strong> Ticket 17531 I have adjustable push rods on a evo, with hydraulic lifters, would I set them with the correct turns and expect them to bleed up? Im changing out the intake pushrod, I found bent to .011 rolling it on a flat piece of glass. Last of the S&amp;S 01' 113cu.in. engine 562 cam, sold in parts and put together by Midwest. Been sitting for years,It has 1000 miles. I put the last 500. Always was hard to start, thinking allot of compression, starter motor, battery, electric's, couldn't get anything more then a grunt and a turn or two. Finally went to adjust the push rods and found that. Any thought's?