Results 1 to 13 of 13

Thread: MF135 Hydraulics query

  1. #1
    Junior Member
    Join Date
    May 2016
    Location
    Cumbria
    Posts
    11

    MF135 Hydraulics query

    I have just hooked my flail mower up to my 135 and I've noticed something odd about the lift arm operation.

    With the engine at idle speeds, the lift arms work fine, relative smooth and fairly quick in operation. However, when I increase engine revs to PTO speed, the lift arms are much slower to raise. I would have imagined it would be the other way around.

    Any ideas whats going. I haven't own the tractor very long, so I cant say whether this is a change or whether it has always behaved like this and I just haven't noticed it previously.

    Any ideas?

  2. #2
    Senior Member T P's Avatar
    Join Date
    Feb 2013
    Location
    The muddy edge of the biggest puddle in the uk
    Posts
    625

    Re: MF135 Hydraulics query

    If the suction strainer is nearly blocked it's plausible that when you raise the revs the pump isn't getting a proper feed of supply oil and the pistons are staying out from the cams instead of a full stroke a low revs you are getting lots of little strokes of negligible volume at high revs. It would be worthwhile draining the oil and removing one of the sidecovers to inspect the suction filter. There were a few models that you could remove the suction strainer throught the bottom via a 3 bolted cover but I don't know the models well enough to be sure if yours is one.

  3. #3
    Junior Member
    Join Date
    May 2016
    Location
    Cumbria
    Posts
    11

    Re: MF135 Hydraulics query

    Quote Originally Posted by T P View Post
    If the suction strainer is nearly blocked it's plausible that when you raise the revs the pump isn't getting a proper feed of supply oil and the pistons are staying out from the cams instead of a full stroke a low revs you are getting lots of little strokes of negligible volume at high revs. It would be worthwhile draining the oil and removing one of the sidecovers to inspect the suction filter. There were a few models that you could remove the suction strainer throught the bottom via a 3 bolted cover but I don't know the models well enough to be sure if yours is one.
    Thanks TP. Is removal of the side cover and cleaning of the filter an easy job?

  4. #4
    Senior Member T P's Avatar
    Join Date
    Feb 2013
    Location
    The muddy edge of the biggest puddle in the uk
    Posts
    625

    Re: MF135 Hydraulics query

    Removing one of the covers is easy enough one the oil is out. There's one with I think the response rate adjuster or dipstick on it or the alternate one with the pto lever on it on the other side. I worked at those machines thirty years ago but it's been a long time. I reckon you can inspect the filter but whether you can get it out without removing the linkage lid I can't remember. I'm sure someone else will be along with the exact details which may vary with date of production as the 135 was in production a long time. I recall a vertical tubular guaze sitting alongside the pump in some sort of massey but it's a bit vague by now. This thread bears out my memory and points to the pto lever cover as I suspected.

    http://www.yesterdaystractors.com/cg...d=mf&th=121975

    Looks like you "unwire" then unscrew it, remove clean and replace. I will have done this more than a few times but all very vague now.

  5. #5
    Member
    Join Date
    Mar 2013
    Location
    wales
    Posts
    41

    Re: MF135 Hydraulics query

    The strainer is on the pto lever side. You remove the pto lever cover on clutch pedal side after draining oil, cut wire that stops the fillter cap unscrewing and remove filter, be carefull when replacing not to cross thread, easy to do it only goes into aluminium, and replace wire, and make shore pto selector fork goes back home before tightening bolts. Very fiddly job through a small hole 😉

  6. #6
    Junior Member
    Join Date
    May 2016
    Location
    Cumbria
    Posts
    11

    Re: MF135 Hydraulics query

    Well, job complete.

    Old oil drained (resembled white coffee) from both drain plugs.

    PTO selector removed. Hydraulic filter removed. Covered in "mayonaisse" type gunk. Cleaned up with petrol, blown through with airline and left to dry.

    Access through the hole was tight and fiddly (I'm not the smallest of individuals) but from what I could see, my pump looked slightly different from the one in the previous link. the reason I noticed, is because I couldn't find the location for the lockwire. On my pump, there is a pipe immediately adjacent to the filter, so I have lockwired the filter to this pipe.

    All re-assemebled and refilled with fresh oil.

    PTO selector works fine. Lift arms work fine and are nice and smooth. I timed the lift with a 6ft flair mower attached and the transit time form fully lowered to the transport position is approx 6seconds with the engine at idle and at PTO speed.

    So all appears fine. Thanks for the help.

    P.S.:- I have ordered new boots for the gear selectors to help prevent any further water ingress into the back end.

  7. #7
    Senior Member T P's Avatar
    Join Date
    Feb 2013
    Location
    The muddy edge of the biggest puddle in the uk
    Posts
    625

    Re: MF135 Hydraulics query

    It would be worthwhile to have a look at the seal on the top link spring assy as it's another place that can let a lot of water into the transmission.

  8. #8
    Junior Member
    Join Date
    May 2016
    Location
    Cumbria
    Posts
    11

    Re: MF135 Hydraulics query

    Well, I thought I had sorted this issue, but I haven't!!

    Currently the lift arms are extremely slow. I mean 10mins to raise, which is unuseable.

    There is something strange going on though, because if I crank the engine on the starter (with the engine stop out), the arms raise fairly swiftly, but as soon as the engine runs, the arms slow right down.

    The issue is obviously related to pump speed.

    I am at a loss now.

    Anybody know of any good mechanics in the South Lakes area?

  9. #9
    Senior Member
    Join Date
    Feb 2013
    Location
    Co Down
    Posts
    368

    Re: MF135 Hydraulics query

    Sounds to me like the prssure relief valve is weak,but would also be worth checking the o rings on the stand pipe first. It's under the small plate to the front of the seat.Two bolts hold it on.(Might be a selector valve on yours as well) Lift the plate off and the pipe, with an o ring and white packer ring on each end, will pull up out of the pump. If not that,then may be worth checking out/replacing the relief valve.
    It's on the opposite side to the filter(the long shiny bit to the right of the drive shaft in the picture) and can be accessed through the other side plate.If you take that plate off and catch the oil whilst doing so,leaving the rest of the oil at the level of the bottom of the hole,and start the engine.See if there is a blast of oil from the relief valve when lifting the arms. There shouldn't be until the arms are at full lift and the lever in constant pumping.If there is constant oil pumping through, the valve is worn or has dirt stuck in it.IIRC,I made up a box spanner (from an old plug spanner) to change the valve. Seem to remember it not being straight forward to unscrew due to access and it's likely wired in as well.

  10. #10
    Senior Member
    Join Date
    Feb 2013
    Location
    Tasmania
    Posts
    767

    Re: MF135 Hydraulics query

    The standpipe from the pump to the lift cover can be a right p.i.t.a. to replace. It will probably come away from the pump when you remove the plate on the lift cover, but if by any chance it stays in place, slip a suitable length of (say) clean 6mm rod down the middle so it is easier to relocate. I don't think there is any thing in the pump at the outlet port it can foul, but agrimax might like to comment, since I'm not a professional.

    I've also found that getting the pipe to seat fully so the plate seals correctly has been a pain, and again agrimax might like to comment - maybe there's a trick or two I don't know.

    JV
    Agtronix - the home of the Weedswiper

  11. #11
    Junior Member
    Join Date
    May 2016
    Location
    Cumbria
    Posts
    11

    Re: MF135 Hydraulics query

    Well

    I sat hear for an hour pondering. What I couldnt work out was why the pump seemed to work ok when the engine was cranking but not running. I wondered whether it was oil starvation. i.e. the pump was losing suction at higher speeds. This could only be caused by low oil level or a blockage.

    The oil was good.

    I had only cleaned the filter a few weeks ago.

    Well I decided to drain soem oil and have another look at the filter. The oil was pretty clean as you would expect. The filter had some visible debris but didnt look too bad. I let the filter soak in a bowl of petrol for half an hour and brushed it vigorously to clean it up.

    I reassembled everything and hey presto, everything is working perfectly again.

    Two lessons form this:-
    1. When I changed the oil originally, I didnt flush the casing with diesel and I suspect that there is probably some "gunk" in the bottom.
    2. Even tough the filter looked clean, it obviously wasnt.

    All is good at the moment, but I think I'll order a new filter and put some time aside in the next few weeks to drop the oil, flush the casing and install a new filter.

    Thanks for all the comments and pointers.

    :-)

  12. #12
    Senior Member
    Join Date
    Feb 2013
    Location
    Co Down
    Posts
    368

    Re: MF135 Hydraulics query

    I've usually found the standpipe to pull up out with no problems,John, and when refitting,just let it swing plumb between thumb and forefinger and it finds the hole.......! Usually just feel it slot in to place so to speak.....
    My thoughts on the relief valve being weak were that when you're cranking the engine there may not be enough pressure to activate the valve but enough for the arms to lift,where as when the engine is running,the pressure would be higher and thus opening the valve if the spring was weak or the seat poor.
    Have seen those filters almost blocked and the hyds still work so there must be either a lot of debris in there or something else amiss.Have seen a fuel filter that appeared to be relatively clean but wouldn't let enough diesel through for the engine to run. Due to water in the fuel,there was a film of almost clear ''stuff'' had formed,coating the filter, that was hard to see. New filter sorted it.Wonder if your hyd filter isn't as clean as you think?

  13. #13
    Junior Member
    Join Date
    May 2016
    Location
    Cumbria
    Posts
    11

    Re: MF135 Hydraulics query

    Quote Originally Posted by T P View Post
    It would be worthwhile to have a look at the seal on the top link spring assy as it's another place that can let a lot of water into the transmission.

    I have changed the boots on the gear levers, but I cant work out how to remove the top link fork to replace the rubber boot. Any ideas?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •