MF 135 Hydraulic Draft Control

Anonymous-0

Well-known Member
We have put new control lever in the pump and also have replaced the control spring and plunger in the top cover (celvis).
Also adjusted everything according to shop manual. When tested with plow using draft lever, the plow was not ploughing evenly. It sometimes lift by itself leaving land unploughed.

Any suggestion, what can be the problem. You expertise suggestion will be highly appreciated as it might save my hassle.
 
Hi,
Just to recap on your adjustments. When you had the control spring removed, did you adjust the spring plunger so that the spring was STIFF to turn by hand before fitting the groove pin?
When you fitted the spring to the cover, did you have the DRAFT lever in the fully DOWN position?

Does the linkage lift the plough clear of the ground of it's own accord without you moving the control levers? If this is the case it would appear to be an internal linkage problem...possibly a bent frame.

If you are sure that all is correct in the internal linkage try adjusting the Response lever on the RH side cover. Move it towards the 'SLOW' end. This will cut down the reaction time to the pump.

DavidP, South Wales
 
Hi David,

I did adjusted the control spring like you said and also installed in back the same way you said.

Yes it lifts the plough clear up the ground where only the ferrow wheel was touching. After lifting, it drops it back 1-2 seconds. Can you please advise more on the bent frame.

Actually the pump frame where the control lever is attached, that frame was bent backwards towards the PTO, I have made it straight. Can it be the problem.

The initial problem with the system was that it was keep lifting and making the relief valve sound. Then the valve becomes stiff and we cant move to release. I changed the control valve and spool only. Should I change the O-rings also.

After I did the changes the pump works fine in lifting and maintaining positions. The only problem is that implement come off the ground with I plough.

Do you feel that I should bend the frame of pump (holding the control lever) like it was.
 
Hi,
The frame that I'm referring to is mounted on the underside of the hydraulic cover. It consists of cam levers running between rollers.
If you look at them you will see that they resemble a dog and a giraffe. You will see a circular shaped framework around the 'giraffe'. These do become bent.

I think that the next step would be to rig up a long bar so that you can simulate the compression force in the top link assembly as if you were ploughing. This way you can easily move from a compression to a tension situation as if the plough were being lifted from the ground. Drain the oil to the level of the bottom bolt on the RH side cover. Remove the cover if not already done. Have an assistant work the bar to activate the DRAFT mechanism. Try it at different positions of the DRAFT lever.

When activated the pump lever will move rearwards to lift the linkage. When the bar pressure is released the linkage should fall. If it continues to rise as appears to be the case then it would appear that something is sticking.

Check the frame rollers for any flats as this can cause problems. As a check on the pump you can move the pump lever by hand very cautiosly to ensure that there is no sticking in the control valve or the lever pivot.

See how you get on with these checks.

DavidP
a113161.jpg
 
Thank You David, I will try this in the weekend will let you know.

Can you please advise what book are you referring too. I can see that its more detailed than MF 27. I want to buy that book so looking forward for your help.
 
The book is the UK/European workshop manual for the upgraded 135. It was published about 1972 and is publication number 1856 027 M1.

Cheers

David
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top