I finished working with the backhoe today and when I parked it I noticed 10 minutes later about 2 gallons of hyd. fluid on the ground. I went back to where I was working last and found apprx. another gallon of fluid with a trail of fluid to where I parked. I have noticed most everything being wet with hyd. fluid on the filler tube side of the engine and that's where I found the bottom end of the filler tube completely off the reservoir today. I guess it's been leaking for a while and today it just blew off completely. I've been having trouble out of my dipper lately and wonder if this is related? Dipper worked fine until I noticed the fluid was low and added3-4 quarts. Soon after the dipper started dropping on it's own and not lifting as normal. Long story short...could there be a breather stopped up which blew off the reservoir filler tube which also has caused a cylinder to not be able to purge air when It was low and then refilled...? Where is the reservoir tank breather and are there any other things that need regular service in a hyd. system besides filters? I have read somewhere that there is a return hyd line that has a screen and magnet? If so, where is it located along with any other screens and such? Thanks from the newb 2002 Cat 420D IT 4wd CAT420DKBLN05489
Dipper cylinder is probably full of air from when the tank was run low. The volume in the tank will change whether you have cylinders extended or retracted. Should fix the leak before it gets very expensive
Yes, the hydraulic tank has a breather. It looks like an inline fuel filter and is in the general area of the top of the hydraulic tank. It should be changed every 500hrs. It's all there in the OMM.
Much appreciated, any clue about a screen and magnet to clean? I need to buy one of those manuals...
There's no screen on the hydraulics. There is one on the transmission. On the opposite side to the filter at about the same level as the front output shaft. Have you checked if there's a pocket behind the seat. It's a common place for the OMM to live.
Thanks for the help. Yes it had one in there but it was ruined: (