850T5 Cam Followers

Discussion in 'Volvo 850' started by Ben C via CarKB.com, Jun 17, 2005.

  1. Is changing cam followers straight-forward, or are there any hidden
    nightmares to worry about?
     
    Ben C via CarKB.com, Jun 17, 2005
    #1
  2. Ben C via CarKB.com

    Mike F Guest

    Assuming you know about the timing belt issues, then there's a couple of
    gotchas with taking the upper half of the head off (to get the cams
    out). If it doesn't come off evenly, i.e. if one side come up before
    the other, you'll break a little (very important) piece of the casting
    off. And it's glued down with a special sealer (no gasket) that needs
    to be spread evenly with a roller. And this sealer makes it tough to
    pull the upper part of the head up evenly, there's a special tool just
    for this job.

    --
    Mike F.
    Thornhill (near Toronto), Ont.

    Replace tt with t (twice!) and remove parentheses to email me directly.
    (But I check the newsgroup more often than this email address.)
     
    Mike F, Jun 17, 2005
    #2
  3. Ben C via CarKB.com

    Tim.. Guest


    To add what Mike has knowledgeably said, you need a device (volvo tool or
    your own made one) to pull the top half back down onto the lower when you
    re-assemble (against the pressure of the valve springs) and also some wire
    both ends to fasten the cams to the top half as you lower them down. There
    is an off-centre slot in the dissy end of both cams you can slide a piece of
    flat metal into to lock them at 'tdc' position also.

    You need about 8 pairs of hands at this stage!

    The cam pulleys will need to come off, mark their position relative to the
    shafts with tippex or similar prior to releasing them- on some cars they are
    NOT keyed to the shaft. Beware.

    I would strong recommend using the puller when releasing the top cover to
    ensure it comes up evenly- as Mike said you will break the casting if it
    does not. It is located on about 8 dowels and it can be tight to release,
    but sometimes they pop up of their own accord.

    The tools I have are made a-la Haynes from 3 old plugs, the insultor and
    innards drilled out and some thread welded on with a cross piece and nut on
    the top. The cross piece straddles the cam cover. Install plugs in 1,3 and 5
    and you can pull the upper half down squarely very easily, or conversely let
    it spring up evenly.

    With respect to the sealer, Volvo sell both the removal thinners and the
    proper sealer stuff to re-assemble it with.

    On *no* account *ever* use instant gasket, or worse silicone, or anything
    else. You will have leaks all over the shop if not worse. The Volvo sealer
    comes with a fine hair roller, which after you have removed the old sealer
    with the thinners you apply a very thin layer with the roller.

    The new tappets must be soaked in clean engine oil for 24hrs first, and
    during this time use your fingers below oil level compress and release
    several times to prime them afew times.

    Hope this helps.

    Tim...
     
    Tim.., Jun 17, 2005
    #3
  4. I managed to pull the cam cover down with the cams resting in place on the
    head. You need to do this very slowly & evenly, but it works. To compress the
    cam-belt tensioner, I placed it on a sissor jack and lifted it against the
    subframe bolt. Again, you have to do this very slowly to allow the piston
    time to retract, but it works. Working on a Tank range has it's disadvantages,
    not least an M1 Abrams firing in your left earhole when you are trying to
    line the pulleys up, but I did find the job to be not beyond DIY capability.
    Thanks for your advice.

     
    Ben C via CarKB.com, Jun 25, 2005
    #4
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