Removing Hydraulic Cylinders on D6 8U/9U

I need to pull the hydraulic cylinders off a D6 8U and have them rebuilt. They are leaking fluid and seep bad enough the blade won't stay up. Looking for some tips/tricks on the easiest way to get them off the machine. I plan on using a tractor loader to support the weight of the cylinder but was more curious about the top hinge point and hydraulic connections. It appears you take the side cap off to slide the cylinder off the upper pin. My questions is how the lines hook up from steel to braided hydraulic line. Any suggestions would be appreciated. Thanks

Guessing Cat rams on a Cat hardnose for dozer?

I just removed the rod and piston by taking the bolts at front of the ram out. Slide the piston and rod right out, never removed the barrel from there mounts. Barrel was deceit so just left it alone. But new seal on the piston (thinking it was just a o ring but cannot say for sure anymore). The seal on the front of the rod is chevron packing on mine. Then piece to compress the chevron has a wiper seal in it. I got lucky and a friend had a large stack of the chevron packing given to him. So I fit all that would possible fit in. The chrome on my rods has flaked badly, but everything sealed well.

Keep us updated on your process and progress. Mine too will need to be done at some point or maybe the next owner can do it LoL.

Ray54 he still needs the back line off to keep the suction from holding it. I’ve help dad do this numerous times. I’ve got a cheap set of crowfoot wrenches that work good for lines on cylinders. And I tied off the front of these cylinders

So they don’t break a line. And to get pins out I’m excited to have a new Air Hammer.

are the cylinder rods pitted or scored if so the cheapest option is to have new rods made and welded to the original rod ends (they machine the weld out that holds the rod eye to the rod and turn up a new bit of chrome rod to suit weld it on to the eye and reasemmble with new seals. much cheaper than new rams or rechroming the old rods.

we did our d4 and we did both rams for the cost of the rechroming of one of them

you dont need to remove the cylinders from the machine you can pull the rods in-situ. remove the pin from the rdo eye and use a lifting fram forklift etc to support the ram body. clean of any dirt and crud.

use the hydrualics to almost fully extend the ram. place clean buckets to catch the oil this clean oil can be salvaged by pouring through a mesh strainer equipped funnel.

support the rod from the lifting jib etc

loosen the the hydraulics flange fittings on the ram they are code 61 fittings (note modern cat code61 hose flanges are thicker than the old stuff and aftermarket such as ryco or parker. you may need a spacer ring to get em to seal up properly if the clamps have been replaced after the change was made or if you have to replace clamp plates).

lossen the bolts that hold the barrel head to the ram once you have the head removed and the rod pulled out let the ram drain.

now you can use clean rags to wipe the barrel clean and inspect for scoring and pitting. light scoring can possibly be honed out.heavey scores or pits can not and will mean new barrel needs to be made. hopefully its just bad seals and the piston hasnt contacted the barrel and fucked it. have a look at cutting edge engineering on youtube for a example of how rebarraling and rerodding is done. kurtis does cylinder rebuilding work as his bread and butter.

if the rods piston and barrel are in good nick it easy to fit new seals. not some rams have a oring between the piston and the rod and this can fail so remeber to replace it too. the piston has to come off the fit new gland seals anyway.

I don't remember taking any of the hoses off. I did remove the Cat front hydraulic unit. Used a Hydreco pump that was given to me, along with a Hydreco 2 valve control unit and tank that came from IH TD 14 with a loader bucket. Creative friend even created a joystick to run both valves with one lever. It worked great to run a tilt cylinder we also added. So I guess we would of remove the suction by removing the Cat unit.