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Cobra Hydraulic Jack - oil replentishment



 
 
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  #1  
Old March 23rd 05, 11:01 PM
Gary Emerson
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Posts: n/a
Default Cobra Hydraulic Jack - oil replentishment

What am I looking for as far as where to fill the hydraulic ramp jack w/
more oil?

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  #2  
Old March 24th 05, 03:38 AM
bumper
external usenet poster
 
Posts: n/a
Default

You would be looking for a little rubber plug, probably painted red, on the
body of the jack about 2/3rds the way up from the base. Some jacks use a
screw to plug this fill/level hole, but the one on my Cobra uses the
aforementioned plug.

If you have never changed the hydraulic fluid in your jack, you might want
to do this. When I did mine after just one season, I found the oil
contaminated with metallic particles. This appears to be from rough
machining, as a very old US made Craftsman jack I checked had clean oil
after some 35 years of use!

To flush your jack, remove it from the trailer, remove plug, hold jack with
fill hole down, open release screw and manually extend and retract ram to
expel the old oil. Put a small amount of new oil in and cycle jack, drain
and then refill with new oil.

I didn't feel that the above, though easy enough, would remove all the
contamination from mine, so disassembled it for a thorough cleaning.

BTW, I think the contamination I found may be responsible for so many of
these jacks leaking etc.

all the best,

bumper
"Gary Emerson" wrote in message
...
What am I looking for as far as where to fill the hydraulic ramp jack w/
more oil?



  #3  
Old March 25th 05, 05:04 PM
HL Falbaum
external usenet poster
 
Posts: n/a
Default

My Cobra hyd ramp jack was leaking , so I did thte following
Now I *really* need help.

Disassembled the mechanism and extracted the jack, cleaned all.
Removed the pipe thread fitting holding the "pump" and removed the plunger
(actually it just came out before I expected it.
Removed the nearby screw-"o-ring" and spring, and the rubber plug on the
fill body.
Removed the dirty oil
Reasembled with clean hydraulic jack oil.

tested--ram goes up & down as expected while actuating the "pump" by hand
with a 3/8" bolt through the "saddle".

Installed the foot operating lever--operated lever by hand--does not work!
Same stroke on plunger as hand operation that does work! Removed lever--it
works by hand! It did work once while I was describing the problem to my
wife, to demonstrate what was taking so long! Then, after installation in
the ramp,-no luck!

Reassembled the entire mechanism, ramp, scissors etc--doesn't work at all.

Drained & refilled via body hole with jack upright and ram closed.

Same problem--works by direct hand actuation-but with lever installed-no
luck.
Side loads by direct actuation, no problem. Stroke length varied, no
problem. The lever does not change the stroke length or produce side loads
much, as the saddle is a fairly loose fit.,

I'm stumped--anyone out there with experience?
Thanks in advance.

--
Hartley Falbaum
ASW27B "KF" USA


"bumper" wrote in message
...
You would be looking for a little rubber plug, probably painted red, on
the body of the jack about 2/3rds the way up from the base. Some jacks use
a screw to plug this fill/level hole, but the one on my Cobra uses the
aforementioned plug.

If you have never changed the hydraulic fluid in your jack, you might want
to do this. When I did mine after just one season, I found the oil
contaminated with metallic particles. This appears to be from rough
machining, as a very old US made Craftsman jack I checked had clean oil
after some 35 years of use!

To flush your jack, remove it from the trailer, remove plug, hold jack
with fill hole down, open release screw and manually extend and retract
ram to expel the old oil. Put a small amount of new oil in and cycle jack,
drain and then refill with new oil.

I didn't feel that the above, though easy enough, would remove all the
contamination from mine, so disassembled it for a thorough cleaning.

BTW, I think the contamination I found may be responsible for so many of
these jacks leaking etc.

all the best,

bumper
"Gary Emerson" wrote in message
...
What am I looking for as far as where to fill the hydraulic ramp jack w/
more oil?





  #4  
Old March 25th 05, 06:00 PM
Gary Evans
external usenet poster
 
Posts: n/a
Default

I assume that you are testing it in the same operating
position for if not it could be a trapped air problem.
If it works by hand but not with the lever that suggests
that you are no getting the exact same plunger stroke.
If that's not the problem perhaps someone put a hex
on the pump when you were not around. You may want
to check with your wife.

At 16:30 25 March 2005, Hl Falbaum wrote:
My Cobra hyd ramp jack was leaking , so I did thte
following
Now I *really* need help.

Disassembled the mechanism and extracted the jack,
cleaned all.
Removed the pipe thread fitting holding the 'pump'
and removed the plunger
(actually it just came out before I expected it.
Removed the nearby screw-'o-ring' and spring, and the
rubber plug on the
fill body.
Removed the dirty oil
Reasembled with clean hydraulic jack oil.

tested--ram goes up & down as expected while actuating
the 'pump' by hand
with a 3/8' bolt through the 'saddle'.

Installed the foot operating lever--operated lever
by hand--does not work!
Same stroke on plunger as hand operation that does
work! Removed lever--it
works by hand! It did work once while I was describing
the problem to my
wife, to demonstrate what was taking so long! Then,
after installation in
the ramp,-no luck!

Reassembled the entire mechanism, ramp, scissors etc--doesn't
work at all.

Drained & refilled via body hole with jack upright
and ram closed.

Same problem--works by direct hand actuation-but with
lever installed-no
luck.
Side loads by direct actuation, no problem. Stroke
length varied, no
problem. The lever does not change the stroke length
or produce side loads
much, as the saddle is a fairly loose fit.,

I'm stumped--anyone out there with experience?
Thanks in advance.

--
Hartley Falbaum
ASW27B 'KF' USA


'bumper' wrote in message
...
You would be looking for a little rubber plug, probably
painted red, on
the body of the jack about 2/3rds the way up from
the base. Some jacks use
a screw to plug this fill/level hole, but the one
on my Cobra uses the
aforementioned plug.

If you have never changed the hydraulic fluid in your
jack, you might want
to do this. When I did mine after just one season,
I found the oil
contaminated with metallic particles. This appears
to be from rough
machining, as a very old US made Craftsman jack I
checked had clean oil
after some 35 years of use!

To flush your jack, remove it from the trailer, remove
plug, hold jack
with fill hole down, open release screw and manually
extend and retract
ram to expel the old oil. Put a small amount of new
oil in and cycle jack,
drain and then refill with new oil.

I didn't feel that the above, though easy enough,
would remove all the
contamination from mine, so disassembled it for a
thorough cleaning.

BTW, I think the contamination I found may be responsible
for so many of
these jacks leaking etc.

all the best,

bumper
'Gary Emerson' wrote in message
...
What am I looking for as far as where to fill the
hydraulic ramp jack w/
more oil?









  #5  
Old March 25th 05, 07:47 PM
HL Falbaum
external usenet poster
 
Posts: n/a
Default

Same position. Stroke is close to 1" by lever, so duplicated that and the
portion of the range.
She wouldn't do that !
Thanks for trying.
--
Hartley Falbaum
"Gary Evans" wrote in message
...
I assume that you are testing it in the same operating
position for if not it could be a trapped air problem.
If it works by hand but not with the lever that suggests
that you are no getting the exact same plunger stroke.
If that's not the problem perhaps someone put a hex
on the pump when you were not around. You may want
to check with your wife.

At 16:30 25 March 2005, Hl Falbaum wrote:
My Cobra hyd ramp jack was leaking , so I did thte
following
Now I *really* need help.

Disassembled the mechanism and extracted the jack,
cleaned all.
Removed the pipe thread fitting holding the 'pump'
and removed the plunger
(actually it just came out before I expected it.
Removed the nearby screw-'o-ring' and spring, and the
rubber plug on the
fill body.
Removed the dirty oil
Reasembled with clean hydraulic jack oil.

tested--ram goes up & down as expected while actuating
the 'pump' by hand
with a 3/8' bolt through the 'saddle'.

Installed the foot operating lever--operated lever
by hand--does not work!
Same stroke on plunger as hand operation that does
work! Removed lever--it
works by hand! It did work once while I was describing
the problem to my
wife, to demonstrate what was taking so long! Then,
after installation in
the ramp,-no luck!

Reassembled the entire mechanism, ramp, scissors etc--doesn't
work at all.

Drained & refilled via body hole with jack upright
and ram closed.

Same problem--works by direct hand actuation-but with
lever installed-no
luck.
Side loads by direct actuation, no problem. Stroke
length varied, no
problem. The lever does not change the stroke length
or produce side loads
much, as the saddle is a fairly loose fit.,

I'm stumped--anyone out there with experience?
Thanks in advance.

--
Hartley Falbaum
ASW27B 'KF' USA




 




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