hi i am interested in repacking the seals in the dipper cyl on my backhoe. what kind of pins hold the cyl in place. i see there is a bunch of snap rings on the ends.
The last time I did it seemed pretty easy, extend the boom all the way out straight dig the bucket teeth in just a little and chain tight from the bucket pivot to the lower frame, unsnap the top snap ring and take out that top piston pin. Having a gland nut wrench helps tons, take out the small set screw at the flange between the gland and the tube. Back the gland nut out all the way, then spin it back in 3 turns. Prop the cyl up a little so the piston rod will clear the clevis and so very gently run the rod out until the piston hits the inside of the gland nut. This seems to put the packing in an area of the bore to where a mere mortal can wiggle and tug it out. Shut down the machine and operate the levers for the dipper a minimum of 30 seconds in each position then tie it forward into the retract position. The gland nut should not have any tension on it once you start to turn it, back it out and then using either a pickup bed, step ladder, pile of pallets, grasp the rod and pull it out of the bore. Fluid loss should be less than a cup. cover the open cyl immediately and don't drop the rod. Remove the giant nut (likely 800-1500 ftlb) then the piston comes off, followed by the gland nut. Digging the seals out of the gland nut is a pain, go slow and bandage your fingers as soon as possible after stabbing them with the screwdriver. Go over the rod with the back of your fingers and feel if there are any nicks or burrs, buff those down with an oil stone or polish the whole rod if scratched with crocus cloth. (more akin to outrigger and swing cyl damage)
Pretty simple to remove a dipper cylinder - nothing tricky about the pins. Support the machine so that there is no load on the dipper cylinder, remove the snap rings on one side, and tap the pin out with a wood dowel and a hammer. Best if you have a helper, since it's high enough on the machine to be awkward. (If you're removing the cylinder from the machine) You'll need a large pair of snap ring pliers - the larger the better. I still haven't found a pair large enough to be easy.
LOL! Sounds like wisdom from someone who has done that before!
dipper cyl rebuild extend the boom all the way out straight dig the bucket teeth in just a little ? i dont really get what you mean by this.
maybe you mean like the main pic of this website the way it is ???
yeah, retract the bucket cyl all the way retract the dipper all the way and lower the boom to the ground, it gets the dipper cyl as close to the ground as possible and tilted upwards so it won't puke gallons of fluid out. Teeth dug in a little and anchored with a chain will prevent the boom from falling and stabilize it while you take it apart a little. Actually when I did it I was standing on the boom and pulled the dipper piston out to find out that all the just below freezing hydraulic oil was charged with air/foam and when that slight pressure was released, it emptied the contents of the cyl up and out like pulling the cork on a well shaken ginger ale. The only spot not covered with oil was between my sneakers and the dipper boom. Cold cold foamy oil from head to toe, had my buddy grab the rod wrap it in a towel and put it aside, back the quad over so I could hop down as the first step would have been all oil on nice paint. Took a roll of paper towels to get me clean enough to go in and dive in the shower. From then on just used a pickup truck bed/tailgate as a work platform.
it seems like if you retracted both the dipper and bucket cylinders all the way and lowered the boom to the ground the whole backhoe section would be relatively parralell to the ground- basically stretch staight out and down-correct?teeth dug in slightyly?
would seem getting good at this would be worthwhile and cost effective- specially if youll own it for any lenth of time-and enjoy working on your own equiptment-
Channellock makes some decent snap ring pliers. I bought the # 929 for mine, and already had the smaller version. http://www.northerntool.com/shop/tools/product_200397467_200397467