MF 135 hydraulic and pto problems

In February got a diesel 135, engine seems great and I love it, but it's a first tractor and there's SO much I don't know… Have read some brilliantly useful posts on this forum but none with quite this collection of symptoms so I hope someone will forgive all these words and be able to offer some advice … I have grass that needs cutting soon!

Don't know the model year, can't find any info plate. Not a multipower. Don't know whether it's a 2 stage clutch: half of pedal travel is relatively soft, then suddenly requires more pressure. Sold to me as having PTO and hydraulics "as they should be" but after standing 3 months in cold weather, though covered, situation was as follows:

PTO seemed OK: with engine running and "engine" selected would turn when the tractor was stationery. With "ground" selected would turn when tractor moved. Hydraulics wouldn't lift any load.

So: dismantled quadrant controls, seemed properly connected to the internal linkages, control valve operation seemed fine, all the bits moved smoothly. Draft and position levers have no functioning stops or markers, draft tends to spring upright.

Cleaned hydraulic filter, thick with a sort of gluey gel, and it now lifts beautifully: manages a long, heavy topper without any problem at all. Hooray.

Put covers back (2 tries to get the PTO selector in the groove), replaced tranny oil, which seemed in good condition: brown, reasonably clear.

Current situation:

PTO: with lever at either "ground" or "engine" the output shaft only turns when tractor moves. This seems a backward step from when I got it! Presumably I've cocked something up. Drat.

Hydraulics: lift goes up and down on the draft control only. Position control has no effect at all.

3 pt linkage stays up when engine is running, but sinks immediately engine is off.

3 pt linkage lowers when clutch is depressed, rises when released (I really don't get this bit).

There is a single output bobbin (?) hydraulic control under the driver's right thigh. It must be open (anti-clockwise) at least half a turn for the lift to work. There is a short output hose from it, ending in a socket which is weeping slightly.

There is a two-output hydraulic control on the left side, but the lever/switch won't turn at all (perhaps locked as there is nothing connected to the outputs?).

I have the operator's manual, but which workshop manual should I get?

Many thanks to anyone who's read this far ...

Hello Witsend, nice handle!!!
You have done well to get so far despite what might be a few hiccups. There are a lot of questions and much to answer so I'll try and work my way through it.
There would not have been any need to dismantle the quadrant controls. The only setting and adjustment in that area is to set the final position control on tractors fitted with PRESSURE CONTROL. The adjustable, thumbwheel and bolted stop are all that is adjusted on non-Pressure Control tractors.
"PTO only turns when tractor moves". I believe that you have lost the engagement of the pto operating lever in the groove in the coupler gear. The gear is permanently in the ground-speed position. Move the lever carefully. Normally you can feel the engagement taking place as the splines 'butt' briefly before engaging. Have another go!!!!!
"Lift goes up and down on DRAFT control only".
I think that the hair spring between the item lines 17 and 18 may be broken or perhaps you have not replaced it, or perhaps ensured that the tails were engaged fully. It is difficult to fit. It is easier using a piece of wire.
"Linkage sinks when engine is stopped". This suggests that you have a significant internal leak. Whilst the engine is running the internal linkage senses a change of position of the lift arms and moves the pump control valve into the pumping position to compensate for the change. This oil loss frequently comes from a worn/broken lift cylinder or piston or rings. As the oil leaks out the system tries to replace it.
No engine running, no oil supplied to the system.
Leaks can also come from the valves in the pump, the O rings on the stack pipe and from the control valve.
"3-pt lowers when clutch is pressed fully". When depressed fully drive to the pump is disconnected. This has the same effect as stopping the engine above.
"3-pt rises when clutch is released". When this happens the control valve is already in the maximum pumping position. As soon as drive to the pump restarts the linkage rises.

The isolating valve mounted on the front RH corner of the hydraulic cover is to seperate and give two hydraulic functions. In one position the 3-pt will work. In the other oil is diverted from the lift cylinder to the pipe with a coupling at the end. This is used for tipping a trailer for example. Ensure that the control is fully 'one way or the other'.

Need a bit more info on the 'two-output hyd control'. Can you post a photo?
There is no question about it. Buy the genuine MF manual if you can. They are available in original paper or cd copies. Any problems, have a look at UK Ebay.

Hope this helps.
DavidP, South Wales

I was just in the forum trying to make a plan for tomorrow's tractor-meddling when your very welcome post came through - thank you - so, the terrier's asleep under my knees and I'll settle down to read ...

The serial number plate on our 135 is under the battery support,
left side of the tractor. Don't know if this is normal, as our other
MF's have it on the left side of dash under steering wheel. Failing
a ser# plate, you might be able to correlate the date from the
engine block ser#, not sure but I think it's on the right side just
below the head on the Perkins 3 cylinder. As David says, you
would be best off getting the factory 135 workshop manual.

Another possibility for the hydraulics could be the pressure relief valve being faulty. If roughly 5 gallons of hyd. fluid is drained out, you can take the right side cover off of the rear end and see inside without spilling oil out. This will expose the top of the control valve, and may also give you access to look at the PTO coupler.......but first lets talk 3 point.

Have an implement hooked up, with the side cover off start tractor and lift the arms slightly, so it puts pressure on the arms. You should be able to look inside that opening, as if kneeling down next to the tractor by right rear wheel, in the bottom right corner you will see a little fitting about the size of your thumb- that's the relief valve. If oil is puking out of there without actually "overloading", that is bad. Another thing to look for is if there is a flow of oil coming from the lift cylinder (through same opening, look inside, to the rear way up high). A small trickle or a few drips of oils is normal, but if flowing steady then the lift cylinder needs attention.

One thing just to cover my curiosity, the top link of the three point controls your "draft", see if that top link is very loose going into the top cover. There is a big spring in there that I have seen break, and cause lift to not work all together, due to draft not working right.

-Richard from MI, USA

Thanks for getting back to me, I'll be looking into that rear cover and will let you know if I find any of the conditions you mentioned. See also photo.

(reply to post at 14:37:13 04/20/12) Need a bit more info on the 'two-output hyd control'.

Click to expand...

Here's a photo of the hyraulic controls. Didn't get anything done on the hydraulics today as the tractor was helping with tree felling: engine great, brakes quite scary though, but they'll have to wait, hopefully tomorrow I can get the oil out again and start looking, but this is going to take a few days I think.

Thanks for the reply: I think my 135 has had a "partial restoration" - lots of things missing, including the info plates. I'll try the engine serial number route. Cheers.

Hi,
It has been suggested that you check the rocker yoke on the rear of the hydraulic cover. That will tell you if the spring is intact but not if there is play there.
To check this move the DRAFT lever fully downwards and check for end float. The spring has an adjustable plunger which over time will slacken. If there is play there you may have difficulty lifting an implement with a heavy top link load. However it will not affect the operation of the three point linkage when nothing is attached.....no load on the top link.
Your photo of the isolating valve is very interesting. I and perhaps others had assumed that you were in the US. Your tractor has a 'MIL'
isolating valve that is Midland Industries Ltd in the UK. The brass tap on the other side was supplied originally with the UK MF 735 loader.
From the small area of fender shown you would appear to have the European flat-tops. Is this correct? The two bolt mounting for the handbrake replaced the 3 bolt one in late 1967.
Are you in the UK or Canada perhaps?
Cheers
DavidP

(quoted from post at 00:48:37 04/22/12)
Your tractor has a 'MIL'
isolating valve that is Midland Industries Ltd in the UK ... The two bolt mounting for the handbrake replaced the 3 bolt one in late 1967 ...
Are you in the UK or Canada perhaps?
Cheers
DavidP

Click to expand...

Yep, I'm in good old Britain, David, Kent in fact: sorry the tractor is not some unlikely export to the US. I got it down from Lancashire, attached is a photo of the dealer badge (the only id I can find apart from the casting codes). Interesting to know it's post '67. Does the pic of the front axle help at all?

Pretty sure there's no end float in the top link, thanks for that.

Have also attached a pix of the hydraulic linkages: I can't actually see the spring you mention. Position control doesn't appear to do anything. Am going to check the relief valve as suggested by Mr Gearhead. Will the lid have to come off (slightly dread the mention of "special tools" and descriptions of how heavy it is. Guess I could get a strap over the kid's swing frame)? I guess if there's a leak you suspected in your last post, as well as a control problem, it'll have to ...

Thought you might get a laugh out of the pto selector that I replaced so carefully, then wondered why it wouldn't work any more ...

There's a load of questions on other pix but really I'm just trying to work out what to do next on the hydraulics. Thanks for your interest and help.

Hi, don't know what to do next, so I'm giving the thread a bump.

2 outstanding problems:

1) Position control has no effect.
2) No lift when clutch depressed, engine off.

I took the plunge and took off the hydraulic cover: looking for the hair spring mentioned by DavidP (have included pic of my version of Special tool 226A).

As can be seen from the pix the spring is there and seems to be fine, the linkages don't seem bent, (would that be obvious?) and now I'm at a loss for what to try next ...

Incidentally, there's no hydraulic cover gasket – the manual says fit a new one,should I? Also the manual says there a 14 cover bolts, I could only find 13 ... any comments?

Also, got to sort the the lift dipping (cylinder is not scored, no sign of cracks, but I've not looked at the piston or rings. Difficult? I've not got a pressure tester.)

Would really like to sort this, and I'm determined to get it done ... any advice very gratefully received! Thanks.