8011 brakes

[ken]

My 8011 brakes have worked not too bad since I've owned the tractor. The other day, however, they stuck on, on the left wheel. I had an awful time freeing that wheel. Has anyone any similar experience and any hints on what caused it and why and how to fix it. I've not bothered to use the brake on that wheel since. I'd like to know if it's a hydraulic issue or the brake band and its mechanical set up inside the axel.
Ken

 

[dave_peters]

The brakes on the 8011 are dry disc brakes, If they have jammed on the most likely reason is lack of lubrication on the two flat vertical links on the back of the tractor that the slave cylinder pushes to put the brakes on, use a penetrating oil to get them free, it's usually the pivot point that's seized.
Other reasons could be a stuck slave cylinder not letting its ram go back in or one of the springs that hold the discs together on the brake expander has broken, this last requires the half axle to be removed to get at. If you do that, get a new oil seal for between the halfshaft and the diff, as its always potential trouble when oil gets on the discs.

 

[lwalsh2]

Hi usually when the brakes stick on especially when they have been working ok is that the master cylinder has not released the brake fluid from the slave cylinder,if this is the case you can quickly free the brake by releasing the brake fluid from the slave cylinder by opening the bleed screw on the slave cyl. and pushing the linkage back,replacing the master cyl will cure this. The 8011 has two brake discs with a caliper between them and is adjusted by jacking up the wheel, adjusting the 12mm nuts above the slave cyl. in until the wheel locks then back the nuts off by two full turns.When the brake stuck on did it get hot with a burning smell as this could indicate that the brake overheated and if so the discs , caliper springs and internal seals could be damaged with oil leaking onto the discs, you will know if this is the case because you will have a good solid pedal but it wont stop you. Liam.

 

[ken]

Thanks gents for this vital information. It did run hot for a while but is free now. I avoided using the brakes till I got my soybeans off and winter wheat planted.

A fellow I know suggested using silicone brake fluid a few years ago. I tried it and it made the brakes work not too bad. However, it got low and I put in regular fluid. I think I'll just relpace the master cylinder if it is fluid presssure that does not release.

On another point: while I was searching the posts on brakes I came across a very good posting about the transmission brake to allow easy shifting. I checked mine and it did not have the stop bolt and lock nut. It had the threaded hole that was filled with grease and perhaps never did have the bolt from day one. That goes in today, it always clashed when shifting.

 

[dave_peters]

While not wanting to disagree with Liam, I havn't yet come across a Zetor whose master cylinder had stopped the brakes releasing......