My Austin-Healey's overdrive is back in business! Or at least
it's producing oil pressure and circulating oil. It seems to
be engaging as expected, too, but it isn't connected to the
drive shaft yet.
What did it take to fix it? Sorry, but I can't tell for sure.
I was trying several things at once. I had removed and replaced
the pump output valve - the check ball may not have been seating
correctly - but that didn't seem to help. Then I drained it
again, removed the valve again, and used compressed air to try
and blow out all the oil passages. This move also conveniently
blew the accumulator piston out, so I could see into the
accumulator chamber. I poured some oil through the passages
where possible, to see that they were clear. This may have
had some priming effect. Also I realized that each pump
stroke delivers only a tiny bit of oil, and there is some
volume in the accumulator that has to be filled up before oil
starts flowing into the next passage. I also tried to clear
the air passage that prevents airlock in the pump - this is a
really tiny passage, too thin to probe with a wire, but I
directed a compressed air stream in the general direction.
Anyway, I put everything back together, refilled with oil,
started the engine, removed the plug over the top of the
actuator valve, engaged third gear, and sat glumly watching
as nothing seemed to happen. Suddenly, after maybe 10 or 15
seconds of running, the actuator passage filled with oil, which
began to overflow down the side of the OD! I quickly shut off
the engine, replaced the actuator valve spring and plug, wiped
off the spilled oil, and went to the refridge for a celebratory
Guinness.
So I can't tell you what really fixed it, but I now consider
myself an expert on the hydraulic arrangement and subsystems
of the Laycock Overdrive. Any questions? My next challenge,
of course, is to reconnect the solenoid, speed governor,
gear selector cutout, throttle linkage switch, two-relay
controller, and associated wiring harness, then join battle
with the Evil One, the spirit of Joe Lucas. Wish me luck.
Jim Beckman AT&T, Middletown, NJ att!mtqub!jeb
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