Hydraulic Arm Removal

[Whitey]

First thread, I hope this is right. I am the third owner of a used early 90s JD 770 with 7 backhoe and 70 loader. (My first compact) I am planning to do some maintanence work on it this winter speciffically the hydraulic cylinders. Some of the cylinders leak slightly on the backhoe. JD wants $ 50 + for a kit, and a local hydraulic repair shop will give me an estimate for free. Either way i am going to have to take the cylinders off. My question is, if I disengage the backhoe from the tractor and start to tear the backhoe apart, how do I releave the pressure in the hoses before dissconnection. Also, is there any opinions out there for doing all the cylinders or just the ones that are leaking.

Thanx.

 

[RobJ]

I would only do the problem ones. To releive the pressure you can depress the check ball on the quick release, or slowly loosen the lines with a rag wrapped around them. Or release the pressure while it's hooked up and the engine off.

Make sure the BH is NOT resting on the pressurized cylinders!! They are easy to rebuilt if you have a couple tools.

Good Luck,
Rob

 

[Wayne County Hose]

Machine is about 15 years old and some cylinders are leaking. The rest will leak by this time next year. Go to this site- Hercules Sealing Products and get your seal kits. The most expensive is $44 and the cheapest is $21. Take about half off as these are list prices. Hyd shop should be under $100 each to rebuild and test. These have the Vee style rod and piston seals which are easy to rebuild.

 

[Soundguy]

disconnect the hoes.. but leve hoses connected to spool.. runt he spool around.. that should dump the pressure..

Soundguy

 

[Wayne County Hose]

disconnect the hoes.. but leve hoses connected to spool.. runt he spool around.. that should dump the pressure..

Soundguy

Hey Soundguy, you letting your kid on the computer again?

 

[RickB]

Hey Soundguy, you letting your kid on the computer again?

He's still sore from that hot poker I used on him the other day.

 

[Soundguy]

No kids.. but lots of cats... They like to set in my lap while I read email... lap is only big enough for about 2 cats.. and i got about 6x that many counting the barn cats. Usually have about 3-4 all walking across my desk vieing for lap time... Add to that I type fast.. like 90wpm... makes for plenty of spelling mistakes when you are looking at the side of a cat between you and the monitor and ya got another one rubbing it's face on your hand while trying to type.

I love em.. so I can't shoe em' away... What can i say.. I like most furry animals ( and some of the larger ones with horns or antlers with ketchup! )

Rick's right on too.. I'm having to set on one of those donut pillows

Soundguy

 

[RobJ]

Add to that I type fast.. like 90wpm...

I can type 90 wpm to. Not sure what language they all are. So I guess if you take those out and the misspells, about 20.

Oh heck I can type 90 wpm. to to to to to to to to or a a a a a a a a a or how about " " That's space!!

 

[Soundguy]

For those of us that actually remember having to take a typing class in school.. the word per minute count could also be done by character content.. not individual words.. etc. At least that's how our instructor did it.

Anyone else use the old original selectric's?

Soundguy

 

[Opti-Mist]

Yup - in typing class! I only got to 60.