MF50H BACKHOE LOADER ROTARY ACTUATOR UNSTABLE...
- Thread starter uniqman
- Start date
Hi all,
regarding above issue, i bought seal kit from pvdobson, uk and i repair it my self. I will not say it's very easy but if you are into mechanics you will be able to do it. will describe below the way to do it.
1.First you must remove the drum from the machine after you remove the 5 or 6 allen type bolts of 1/2" that hold the actuator on the machine body. Note that the one bolt is hidden right under the return oil line of drum.
2.Put the drum on a stable base (use 2 robust wooden blocks to support it and let the splined shaft extension between the blogs down under)
3. unscrew and remove the, i thing 10 bolts of the top cover. You will notice there are three bolts slots in a triangle pattern that will accept 1" screws. cut 3 pieces of 12 mm diam. and 7.5 cm length of metal rod and drop each one in the holes. Support the main central shaft in such a way that won't lift along with the top cover. Then screw the three bolts equally till the top cover lifted completely. At this point you can remove the steel ring (collar) of main shaft. Take a note that the rounded side is facing down. Then carefully remove the orifice plates and springs. Mark their position.
4. Make a cover out of sturdy wood exactly as being the top cover (dummy) and support it with 3 bolts and flat washers. you can use from the ones removed with the addition of spacers to cover the distance.
5. Turn the actuator upside down. Remove the bottom cover in the same way.
6. lift the main shaft very carefully. (it's heavy).
7. Unscrew the 8 bolts on the side of the rotor 1/2". Remove the 1/4" bolts as well. Under the 1/4" bolts there are steel shafts that connect the stopper on to the rotary body. Very carefully using a chisel of almost same diameter hit the steel shafts at a sequence from the middle and cross diagonally towards the two ends. This needs patience as this parts is there ever since the machinery was build.
Once removed replace the seal and supports. Make sure you lubricate well parts prior. Put this stopper back, using it's own bolts but using spacers. Tight them is a sequence will pull it back to it's position. Make sure you lubricate the steel shafts and slots and also the parts must be pulled back very straight, otherwise will lock.
8. replace main shaft seal and seal supports and put it back. Make sure that the shaft sits in the same position as when removed.
9. Replace the main seal on the actuator body and also the seal and scraper on the cover neck. Use a lot of hydraulic oil on all seals and shaft.
Lower the cover slowly and using three bolts to locate the screw slots let is rest with it's weight. Tight all main bolts of cover with hand strength , in a sequence as described before.
10. Turn the actuator upside down and follow the same process. (put orifices and springs in the same place removed). At this point i pour hydraulic oil in the empty space. This will give enough lubrication to the wals of actuator and also will need no time to remove air from the system when put back.
11. Using a pry bar and a tube i locket the actuator and i tight bolts to 200 lbf-ft
Now the part is ready to be put back
Now will try and attach some photos taken. Good luck to the ones will try this.
regarding above issue, i bought seal kit from pvdobson, uk and i repair it my self. I will not say it's very easy but if you are into mechanics you will be able to do it. will describe below the way to do it.
1.First you must remove the drum from the machine after you remove the 5 or 6 allen type bolts of 1/2" that hold the actuator on the machine body. Note that the one bolt is hidden right under the return oil line of drum.
2.Put the drum on a stable base (use 2 robust wooden blocks to support it and let the splined shaft extension between the blogs down under)
3. unscrew and remove the, i thing 10 bolts of the top cover. You will notice there are three bolts slots in a triangle pattern that will accept 1" screws. cut 3 pieces of 12 mm diam. and 7.5 cm length of metal rod and drop each one in the holes. Support the main central shaft in such a way that won't lift along with the top cover. Then screw the three bolts equally till the top cover lifted completely. At this point you can remove the steel ring (collar) of main shaft. Take a note that the rounded side is facing down. Then carefully remove the orifice plates and springs. Mark their position.
4. Make a cover out of sturdy wood exactly as being the top cover (dummy) and support it with 3 bolts and flat washers. you can use from the ones removed with the addition of spacers to cover the distance.
5. Turn the actuator upside down. Remove the bottom cover in the same way.
6. lift the main shaft very carefully. (it's heavy).
7. Unscrew the 8 bolts on the side of the rotor 1/2". Remove the 1/4" bolts as well. Under the 1/4" bolts there are steel shafts that connect the stopper on to the rotary body. Very carefully using a chisel of almost same diameter hit the steel shafts at a sequence from the middle and cross diagonally towards the two ends. This needs patience as this parts is there ever since the machinery was build.
Once removed replace the seal and supports. Make sure you lubricate well parts prior. Put this stopper back, using it's own bolts but using spacers. Tight them is a sequence will pull it back to it's position. Make sure you lubricate the steel shafts and slots and also the parts must be pulled back very straight, otherwise will lock.
8. replace main shaft seal and seal supports and put it back. Make sure that the shaft sits in the same position as when removed.
9. Replace the main seal on the actuator body and also the seal and scraper on the cover neck. Use a lot of hydraulic oil on all seals and shaft.
Lower the cover slowly and using three bolts to locate the screw slots let is rest with it's weight. Tight all main bolts of cover with hand strength , in a sequence as described before.
10. Turn the actuator upside down and follow the same process. (put orifices and springs in the same place removed). At this point i pour hydraulic oil in the empty space. This will give enough lubrication to the wals of actuator and also will need no time to remove air from the system when put back.
11. Using a pry bar and a tube i locket the actuator and i tight bolts to 200 lbf-ft
Now the part is ready to be put back
Now will try and attach some photos taken. Good luck to the ones will try this.
loopman
Bronze Member
- Joined
- Sep 9, 2013
- Messages
- 50
- Location
- Tamworth, Australia
- Tractor
- Iseki 4270, David Brown 990. Ford 4500, John Deere STX38, BHB Bobcat
Hi Uniqman, great details there and pictures. Just about to embark on trying to fix a similar unit on my Ford 4500 backhoe (Cessna rotary swing cylinder) and your post will be a tremendous help. Unfortunately all my parts enquiries have returned "no longer available" for a seal kit. Your unit looks almost identical, wondering if anyone knows if the seal kits are the same between these models?
tonioaltea
New member
hello, can you tell me where I can find oring parts for rotary actuator cylinder of masseyfergusson 50A, similar to this pubbici, thanks
hendersontr
New member
- Joined
- Jul 30, 2018
- Messages
- 5
- Tractor
- MF2200 Allis WD/CA
I just ordered a seal kit from Robinson Equipment in Mims Florida 3030 Cuyler street. 321-248-3438. Seal kit was $705.00. I would like to hear from Uniqueman or any hydraulics people that has some experience in this breakdown
hendersontr
New member
- Joined
- Jul 30, 2018
- Messages
- 5
- Tractor
- MF2200 Allis WD/CA
I have the 
MF 54 On the back of a MF2200. This should be fun to get too. Tim 904-860-7340. If you have some good tips
MF 54 On the back of a MF2200. This should be fun to get too. Tim 904-860-7340. If you have some good tipshendersontr
New member
- Joined
- Jul 30, 2018
- Messages
- 5
- Tractor
- MF2200 Allis WD/CA
Mf54 Cessna Rotary swing cylinder Seal Replacement - YouTube I hope this helps
swampdigger
New member
Glad you guys are still fixing these things. I'm about to start rebuilding mine in a few weeks. Rotary swing cylinder works great, but all my bearings and pins are toast. I cross referenced the upper and lower bearings and found some same size units for cheap. That lower bearing is big bucks if you have to buy one brand new.
The flange that receives the splined shaft of the rotary cylinder--it has 4 bolt holes and 2 dowel pins. Well, mine is toast. All the holes wallowed out. Either I build up weld and redrill and tap it all. Or I was thinking about just welding the bastard solid. Weld it instead of using the bolts. The rotary cylinder will still slip in and out of it, but it'll be welded solid to the base.
Is there enough room to lift the rotary cylinder in and out with that flange welded in place? It was a last year when I tore it all apart, but I think I left the flange on the end of the cylinder when I pulled it. I'm afraid there isn't enough clearnence to leave that flange in place, and pull the swing cylinder high enough so the shaft can come right out of the flange.
Thoughts anyone? Can I weld that flange in place, or should I start ordering tooling to fix all the holes in the flange?
The flange that receives the splined shaft of the rotary cylinder--it has 4 bolt holes and 2 dowel pins. Well, mine is toast. All the holes wallowed out. Either I build up weld and redrill and tap it all. Or I was thinking about just welding the bastard solid. Weld it instead of using the bolts. The rotary cylinder will still slip in and out of it, but it'll be welded solid to the base.
Is there enough room to lift the rotary cylinder in and out with that flange welded in place? It was a last year when I tore it all apart, but I think I left the flange on the end of the cylinder when I pulled it. I'm afraid there isn't enough clearnence to leave that flange in place, and pull the swing cylinder high enough so the shaft can come right out of the flange.
Thoughts anyone? Can I weld that flange in place, or should I start ordering tooling to fix all the holes in the flange?
If you weld it, I do not believe you will ever the the swing frame and pivot frames separated. I added (4) more bolts to mine and (2) new dowels. The palte is now secure, but there is significant backlash in between the ouput shaft of the swing cylinder and the plate. That is something I may just have to live with.