mf 85 brakes

farmerscotty · Oct 2, 2016

my mf 85 has one brake that sticks........you have to back it up and jab the pedal to get it to release to go forward........

if you don't do that it is stuck.......

any idea on how to fix this........

marloweg · Oct 2, 2016

very common problem the brake are two plates with balls in between that are on holes that are wedged. the ball and plates rust and ware and get flat spots on them. you must pull the trumpet to get at the assemblies sometimes a good cleaning will work but most of the time new parts are needed. your return spring could also be broke

DavidP, South Wales · Oct 3, 2016

Hi,
This is generally due to worn brake actuators. The actuator consists of two discs with ramps internal ramps in each. When the brakes are applied the discs turn in opposite directions and as the balls run up the ramps the discs are forced apart to clamp onto the discs. When the brake jams on it is normally due to one or more of the balls not sliding back down the ramps to allow the discs to close up. A new actuator will generally cure this but I have found that it is not guaranteed. Each actuator 'floats' against 3 lugs in the axle housing. If the surface of these is worn or rusty this will hold the brakes on. When overhauling dry brake systems I normally clean the lugs using a 4" angle grinder with a coarse sanding disc. Also I have found that a smear of thick copper grease on the contact points of the lugs will give a smoother operation and release. It may sound contrary to apply grease here with potential brake dust present but in the numerous MF, IH and Leyland tractors that I have done this on, not one has given any further problems.

DavidP, South Wales

mf 85 brakes

farmerscotty

Member

marloweg

Well-known Member

DavidP, South Wales

Well-known Member

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