Tractor Talk - Hydraulic Cylinder Swapout

After the new cylinder is installed and fittings are started you could push the bucket up with a jack to expel the air.

Work the control valve back and fourth to get the air out. Then tighten the fittings.

As one applies hydraulic fluid to one side of the piston, what ever is on the other side of the piston is going to go back into the oil reservoir. The bleeding is done for you.

OK

Before you hook up any lines to the cylinder, try to attach the cylinder to the tractor. You should be able to push, or pull the cylinder end until it is the correct length to attach it to the moving part of the tractor. Once the hoses are attached, the cylinder will not want to move.

many helpful post already...don't know how old your tractor is...lets assume the motor is not running... it's possible that the reservoir is self bleeding..1st step:. measure the exposed chrome of the new cylinder.. from the end gland nut to the center of the mount bolt hole..ensure that when you block up the loader basket that the same amount of chrome is shown on the new actuator AS THE OLD ACTUATOR !! IF THE NEW ACTUATOR IS FULL RETRACTED..MAKE THE TWO " CHROME" AREAS THE SAME LENGHT.. SOME PULLING MAY BE REQUIRED.. relieve all system pressure..either by the reservoir relief valve or " crack " ( slightly open ) THE LARGER of the 2 fittings.. that should be the return line.. drain the fluid off..now with pressure relieved.. ( & the WEIGHT of the loader basket supported..) remove all lines. (2) a pressure and a return line..don't worry about the trickle of fluid coming from the small line..2nd step: remove and replace the actuator.. connect the pressure line then the return line .. careful.. do not CROSSTHREAD the fittings..

now the fun starts...

if you've decided to change fluid.. filters should be done now as well...might wanna inspect the lines at this times as well... i hate doing all that then the hose splits....... assuming your changing fluid..

now.. find the hyd sys fill port....might be on the reservoir itself..fill till full.. operated the loader..if the reservoir is self bleeding.. your done...

i might think if there is a bleed valve for manual bleeding it would be before the fluid would return to the actuator... if so.. bleeding is done just like your car brakes..

close the "b- nut " on the actuator, cycle the loader .. up full then down full..crack the return line.. if you crack the pressure line , you'll see right away thats the WRONG LINE ...air will cause the fluid to get frothy or bubble..crack the nut let some fluid drain..( till the bubbles stop or a few seconds which ever comes first.. top off the reservoir between each cycle.. we don't wanna cavitate the system..( yes i mean : cycle the loader basket ) repeat as required till the fluid comes out with no bubbles in it.. & all that before lunch?

so that should handle the bleeding problem for ya.. gl..

thank you very much guys. Lynn

Once you replace the cylinder, connect the lines, check for proper fluid (or change) level, Start the engine, raise the arms, rotate the bucket, lower the arms all the air will be displaced and vented out through the vent in the hydraulic storage tank, usually the fill cap is the vent for the tank.

Good luck!

If the chrome shaft is OK, it is lots cheaper to replace the seals and guide bushings on the old unit. Even if the shaft surface is damaged, it can be rechromed and restored if a replacement is difficult or impossible to obtain. The hydraulic shop and machine shop services may not be available in your area, which will influence the decision. Down time considerations also apply. Swap out is fast, rebuild will take a few days of elapsed time.

If replacing is the way to go, be sure the new cylinder is made for the same working pressure as the old one and has the same closed and open lengths so the linkage will not get torn up.

Very important not to stall out cylinder before you cycle at least 6 or 8 times. Any air that is in the cylinder bore will cause "dieseling" under high pressure, and damage your cylinder.

I change out hydralic rams and hoses all the time between different implements and tractors. Bottom line is this. Don't worry about it. The air will rise to the surface of your hydralic oil reservoir and cause you no problems. Just do it!!!!

Hi,

You don't mention the actual hydraulic system used on your tractor, many old ones used the transmission oil as the 'fluid' and the pump is buried in the bottom of the transmission housing. This oil is clearly different in both viscosity and properties than a modern 'hydraulic' equivalent and if you are swapping the old cyclinder for perhaps a 'new' secondhand one you should see what remnants of oil remain in it before fitteng to your tractor,as the seals are not necessarily compatible with a different oil formula.

As others have said bleeding is not a problem. But I would always partially fill the cylinder before fitting as this limits the amount of air to be 'processed' by your system.

Cleanliness is the key feature of any work on an hydraulic system so take every care when making the connections, especially with second-hand/reclaimed bits and pieces if you are not able to see how and where they have been stored, dirt introduced by this route could do damage to your whole system.

Hydraulic tractor oil , transmission fluid, or motor oil are all petroleum based, and the seals are the same. When phosphate ester, or brake fluid are used, seal compatibility is an issue.

good suggestions. thank you all very much Lynn