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hydraulic cylinders

truecountry

Senior Member
Joined
Sep 24, 2007
Messages
410
Location
clarksville va
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Shop Manager and Tech
what tools are used to repack a piston on a hydraulic cylinder , 2 in outside piston ,, inner groove seal seat is 1 3/4 .. seal measures 1 3/4 inside .. its a hard plastic solid seal with o ring on one side ......no way i can do it by hand.dont want to damage seal with screw drivers . tried the old freeze piston heat seal trick and noppppppppppppe dont work
 

willie59

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Joined
Dec 21, 2008
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13,361
Location
Knoxville TN
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Service Manager
Please send a picture of it. Pics always help on something like this because your looking at it, we're not. Pics always make it easier for us. :)
 

Skidder

Member
Joined
Mar 6, 2009
Messages
7
Location
Cape Breton
Hi truecountry, here is how I put the packing on a piston. I start the seal in by hand, I take a small screwdriver with a round shank. I lay the screwdriver on the side of the piston,under the seal. The screwdriver is covering the seal groove, I push the seal in by hand as I work the screwdriver around the piston. I use the screwdriver to strech the seal not to pry the seal. Hope this makes sense. Skidder
 

willie59

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Dec 21, 2008
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I'd still like to see a picture of it. I've done all kinds of cylinders and seals and I don't recall working on a hard plastic seal as truecountry describes with an o-ring on one side. I'd like to see it.
 

bordercollie

Well-Known Member
Joined
Aug 10, 2007
Messages
67
Location
Michigan
Occupation
Dealer service tech with 20 yrs experience,
I think he is trying to describe a seal with a o-ring in the lip side of the seal.

I have done this before, lay seal in groove of piston, place piston in vice, (jaws on flat surfaces) take a large zip tie and go underneath seal and make a loose loop out of the zip tie, hold seal in groove, put your hand through the loop of the zip tie and start stretching the seal while working it into the groove with your other hand, cuntinue pulling and stretching the seal around the piston.

place some grease on the seal to help the zip tie slide around the seal easier, be careful to keep the zip tie from cutting into the seal, use a large zip tie(wider). after the seal is located in the groove, cut the zip tie and remove.

This method works for me and keeps from jabbing a pick or screw driver into my hands.
 

truecountry

Senior Member
Joined
Sep 24, 2007
Messages
410
Location
clarksville va
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Shop Manager and Tech
hi wished i could have gotten the pic .. the piece of equipment is a barko 160c and the seals went in the rotobec grapple to make it swing or turn .. it had 4 plastic like seals that had o rings inside on flangled side at the upper end of these are a oring and plastic washer.. the seals were same size as shaft so screw driver was not going to do it ...
 

willie59

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Dec 21, 2008
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Knoxville TN
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Service Manager
Looks like a typical PolyPac U-cup seal. Shouldn't be a problem installing it on a piston. Get one part of the seal in the piston groove and start working it in, these are very durable seals, doubtful your going to break it. One thing you can do to make the seal more pliable is to place the piston and the seal in a pot of water on a hot plate. Heat the piston and the seal, you don't have to get it boiling, just sufficiently warm/hot. Pull the two out of the water and start working it on. The heated piston helps keep the seal warm while working it, and you'll work quickly, that hot piston won't let you keep your fingers in one place for too long. If you get a chance, send a pic of the piston. :)
 

truecountry

Senior Member
Joined
Sep 24, 2007
Messages
410
Location
clarksville va
Occupation
Shop Manager and Tech
wishes i could have gotten you a pic , it was a shaft 2 1/4 " by 36" grooves were at 2" from bottom ,3", seal flanges to bottom(4" was a hydralic port cut to the left 5" another hydralic port cut to the right ) then ,seal groove at 6" and 7" seal flanges to top then oring groove and washer.. top of shaft has two ports drilled down to 4 and 5 inch ports...........again wished i had pic shaft ... dont think i could have gotten seal down 2 inches and gotten it on the way you explained and the other seals had to go over it or work one all the way down to the 7 " groove........ it really has me puzzled im pretty good at firguring things out after i look at how they work ....and pisses me off too i couldnt .. hydralic shop owner smiled at me when he seen what i had ..took 10 mins to put seals on and would not let me watch.. billed me no charge...again im pissed cause i couldnt do my job even thou no charge............ im a 39 year old community college grad diesel - heavy equipment tech ,,,,,present to mid 2007 saw mill diesel tech then from mid 2007 to 2006 i worked at a trucking company as main tech and only tech with 2 helpers for 38 trucks and over 200 trailers .open top walking floors ,possum bellys , logging, cats, cummins ,ac inspection .grrrrrrr too much work not enough money but needed the floor time ,before then cotton weaving loom tech 1987-2005 due to company shut down and moved overseas ............i love my job just hopes my job lasts a long time.............good luck all in these hard times
 

SterlingR

Formerly DRESSTA1
Joined
Jan 27, 2009
Messages
178
Location
Virginia
truecountry we are neighbors. I live in Keysville. If you ever get in a bind give me a shout. I am in Clarksville a lot. In fact if everything works out will be on the lake this afternoon. lol
 

truecountry

Senior Member
Joined
Sep 24, 2007
Messages
410
Location
clarksville va
Occupation
Shop Manager and Tech
kool i was from charlotte ch ,,married and moved here...hope wind didnt get to bad on u ... i live near bluestone .mooresville estates have a dock to fish off dont need a boat ...lololol.. crappies arent biting at all this week..........
 
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