Previous history
of the car; how I found and bought it (1994) .. |
Diagnostic
inventory, dismantling, survey work to be done (1995-96) |
Mechanical matters (1997-98) |
Body repairs (1999) |
Painting (1999-2000) |
Begin reassembly (2000) |
Reassembly continued |
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Click on the
required page |
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Problems with the top |
At last the upholstery! |
Getting wired for music |
Still
more reassembly (2001)) |
Seats and door panels go in |
First venture out of garage; lining the top |
After 7
years, roadworthy! |
The
Story without end .. ( 8 ) |
Completed on september 2000
A battery, a pair of electric cables, the hydraulic pump reservoir filled --
everything ready for a test of the convertible top mechanism! This first trial lasts only
a few seconds, for as soon as the top cylinders begin to extend, here comes a dribble of
oily fluid from the end of the electric pump motor housing. So we need to tear into the
motor-and-pump assembly. Half an hour later it's all in pieces and we know that the
"o" ring seal between motor and pump is not doing its work, for the motor
windings, carbons and contacts are awash in fluid. Let's clean it all up and put in a new
O-ring. With everything reassembled, another test, same result. This calls for machining
the pot-metal seal chamber and inserting a new seal that fits better.
The job is entrusted to a machinist, who also orders a new seal ($18.25 for a part 8 mm.
in diameter, $19.55 for labor). Another reassembly, another refill of fluid, test again.
That did it, no leak! How do the top cylinders work now? The rods extend and retract, but
one moves faster than the other. I did well not to attach them to the top rails! Really
bizarre... Let a night's sleep bring wisdom and we'll see about it tomorrow.
The next morning, a cruel setback, for once again I see a little hydraulic fluid
dribbling from the motor housing. With everything taken apart once again, I find the motor
soaked in fluid. What in the world ? Another test: I set the assembly on the bench, motor
end down, and fill the upper end of the seal bore with oil to see how it's getting
through. After four hours, no fluid has escaped. The seal is tight, then, so how is the
fluid getting into the motor? I study intently the pot-metal pump body. Two curved
channels that convey fluid to the orifice of the pump outlets run very close to the
central axle-seal bore. Close examination reveals a tiny puncture on the BACK side of the
seal. Now it becomes clear -- the machinist enlarged the bore slightly for the new seal to
fit (figured in mm, not inches) and removed enough material from the thin chamber wall to
let a tiny hole open when the pump worked (it exerts up to 275 lb/sq.in.)
It was a great relief to solve the mystery, and not a big job to fill the puncture with
Araldite, a two-component metal adhesive. Just to be sure, I added a thin coat of the
stuff all around the pump chambers. Sure enough, on the fourth try there was no more fluid
leakage.
Still to be answered, though, was the question of how come a fast rod piston vs. a slow
one. One of them reached full extension two seconds ahead of the other, or to put it
another way, when one was extended the full distance, the other had two inches to go. It
wasn't a pump problem, for both supply lines to the actuators branch from a tee fitting.
The flex supply hoses don't leak, they're new. The top cylinders, well tested by now, show
no fluid loss. It's evident that the right cylinder is always the fast one. I tried
switching the right and left cylinder and their supply hoses (not fastening the jacks to
the body, because the mounts are different). Same result, the one on the right was the
faster. The problem, then, couldn't be in the cylinders themselves. So what difference was
there between left and right? One obvious difference was in the lengths of the two
supplies -- the right tube was half as long as the left. At this point you need to know
that on the Imperial, the pump is under the right rear seat, unlike all other
Chrysler-made convertibles, which mount the pump in the middle behind the back seat. Why
the anomaly is anybody's guess. In dismantling the car at the beginning I noticed the
different lengths of the old hoses (installed in Ghana) and ordered new ones to the same
measure. Kanter obeyed without question. I had recklessly followed the example of the
practical, thrifty African repairman: Why put in two five-foot lengths of supply hose when
one five-footer and another half as long would do the job? If I had looked in the parts
manual I'd have seen that it specified hoses of the same length for all Chrysler-built
convertibles, including the Imperial (check if you like, 1753 554), as if the Imperial
pump was in the middle like the rest. The unequal-speed phenomenon contradicted the law of
hydrodynamics that keeps the pressure at the far end constant, no matter how long the
pipe. Nonetheless I put in a new five-foot-long line on the right side, and hydraulic law
or not, the result was positive.
Better, I mean, but not perfect, for one actuator piston kept reaching the end of its
travel ahead of the other. Now I had attached each of the cylinders to its rail, but so
far I had not linked the two rails with their top bows and header, for fear of twisting
them. The disparity was small now, but it was there. A puzzle to make one tear one's hair.
Here were two hoses of the same length, same diameter, and yet ... I had tried many
up-and-down cycles hoping that the difference would iron itself out. One more test -- now
what ? When I connect the power the motor suddenly slows down, and a big spark flies. It's
burned out ! My guess is that all the fluid soaked up by the motor finally
destroyed one of the windings. Rebuilding the old motor would have been quite costly, so I
ordered a new one for $200 from Hydro-e-lectric. Also, who knows if the Araldite-patched
leak wouldn't open up again? One
piece of good luck: A friend in Florida was going to be in France in three weeks, and he
offered to bring along the new motor.
In a few weeks, here it was, new and shiny. Mount it, try it, and yes, the rails still
won't move in unison. I turned for E-mail advice to Hydro-e-lectric. The answer was that
my "problem" isn't one after all. The behavior that worried me is normal. When
the rails aren't tied together with their bows and header, they always move at different
rates, perhaps because of little differences of seal tightness in the cylinders. If the
test is done with the top mechanism complete, they assured me, it'll work fine. Great
news, hope returns, but before I try again, I must reattach the bows and header. They
needed new tacking strips -- I don't even know what they're called in French, but they are
gasket-like strips of cardboard to which the fabric top staples. On my Imperial, the old
ones were of wood ! The dimensions of the strips sold by Kanter and others weren't right
at all, so I made new ones of hard rubber. They look fine -- here's hoping they hold up.
Vacation time, and work resumes in September. On go the header and top bows, which move
the rails laterally a little and thus make necessary one more adjustment of the windows !
But now's not the time to worry about that, let's see if the *#-)#* top mechanism works.
All in place, first a prayer that the bows and header don't get twisted into spaghetti. A
miracle, everything is fine, one side doesn't get ahead of the other. Hydro-e-lectric was
right then, I needed to test the fully assembled framework, not the side rails
independently. In that case, was there any point in lengthening the right-hand
supply line to its full five feet ?
You can be sure I'm not about to change it back. Now that everything works well and
doesn't leak, I'm happy to leave the question to some future restorer of the car, several
dozen years from now. It'll give him something to meditate on. Three months working on the
top is enough, so let's change the subject (and re-re-re-adjust those windows).
STILL NO NEWS FROM GARY GOERS, and a piece of ominous news from
the FWDLK mailing list, to the effect that Gary is so loaded with work that he is turning
down all new orders. I'd better do something about this soon. He had $2000 from me in
advance and that's been two years ago!
Thanks to Frank L. Peters Jr. from St Louis (Mo)
for the translation ...
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