Dirk de Boer asked:
> On Sat, 5 Oct 1996 22:38:01, -0500
> VRHS43A@prodigy.com (MR JOHN H TWIST) wrote:
> >Burning through the valve guide
> >seals evidences itself at idle and deceleration (CLOUDS of smoke). Fit
> >Felpro SS70373 umbrella oil seals (for the MGA and MGB) - this can be done
> >without removing the head.
> I looked into this a few weeks ago, after doing this job succesfully on my
> 1974 Volvo 142, but I couldn't see how I should compress the valve springs
> on the MGB engine. The point is that the valve springs on an MGB are double,
> so what do you do? I have a Deslisle valve spring compressor which hooks
> onto the valve springs and then pushes down onto the valve cup so you can
> remove the keeper circlip and the keepers. Getting the spring compressors
> hooks in deep enough so they can reach the inner valve spring seems
> impossible. Any tips, John? Anybody on the list ever done this?
I've replaced valve stem seals in situ on an Audi or two, but I don't remember
doing this to a B. However, the procedure is the same. Since you've done
this to a Volvo, you must know about pressurizing the cylinder to keep the
valves from falling into the cylinder. For those of you who don't know, this
requires a hose that screws into a spark plug hole and has a compressed air
fitting on the other end. I have a compression gauge that's in two pieces
with one piece being exactly this setup. Compressed air is applied to the
cylinder (with a pressure regulator!) with the cylinder at top dead center.
The pressure holds the valves up so they don't fall into the cylinder when the
keepers are released. This is also the setup for checking leakdown on a
cylinder to find where compression is being lost.
To remove the valve stem keepers, I use an impact socket bigger than the
keepers and a compothane (deadblow) hammer. The socket is placed on top of
the valve spring cup and smacked smartly with the hammer. The keepers pop out
when the springs are compressed far enough and fast enough that the valve
stays in place. With this method, the springs don't go anywhere and the
keepers stay in the socket. Installation is the reversal of removal, or
whatever the slogan is. When it's time to put the keepers back in, set them
on top of where they go and smack away. After bouncing all over the place,
they'll eventually fall back in. It's magic. This also works with the head
off the car and a rag under the valve.
Of course, with the head on the car, the rockers have to be pushed out of the
way for this. If the rocker assembly is removed, the head needs to come off
because four of the head studs are holding the rocker assembly on.
Personally, I prefer to remove the head and do everything else at the same
time. If there's something wrong with the valve stem seals, there's probably
something else that's wrong.
Denise Thorpe
denise_thorpe@cpqm.saic.com
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