FMD Brakes

JohnnyBoy · Post by **JohnnyBoy** » Tue Oct 12, 2010 9:55 pm

I’ve been having a look at my major’s brakes today and one thing that seemed strange to me was the brake pedal only travelled about halfway to what I would have expected before the lever in the brake that operated the shoes struck one of the 4 back plate mounting bolts. Is this normal?

JohnnyBoy · Post by **JohnnyBoy** » Sun Oct 17, 2010 11:17 pm

I think I’ve found out what the trouble is with the brake, the cable seems to be adjusted wrongly taking up the slack in the drum by partly expanding the shoes rather than the brake adjuster taking up the slack.

JohnnyBoy · Post by **JohnnyBoy** » Mon Oct 18, 2010 11:07 pm

Hoping someone like Brian will pick up on this and tell me if I’ve got it all right.

I’ve stripped both sides of my FMD’s brakes down, cleaned them up and re assembled them using new spring kit on both sides but the new kits don’t look like the ones i’ve replaced nor did the offside brake spring arrangement resemble the nearside brake spring arrangement.

Notice the pull off spring by the adjuster just hanging from the top shoe and the pull off springs on the expander side were rusted, the hold back springs appear to be fitted the wrong way around and the small metal discs appear to be missing. Also with the brake pedal fully raised the expander appears to be partly activated as the cable has been over adjusted.

On the nearside assembly only 2-brake springs have been used and again the hold back springs seem to be fitted the wrong way around.

This is the way I’ve fitted the replacement spring kits, pictured is the nearside brake. My reasoning is the wheel turns anticlockwise when the tractor’s traveling forwards therefore the brake drum turns clockwise. Recalling my dad’s explanation of braking systems back in the late 70’s and my college work at the time, this is a leading/trailing arrangement with the top shoe leading and the bottom shoe trailing. However with the floating adjuster, a heavier pull off spring should be fitted to the leading shoe to enable it to activate first then letting the self energing effect increasing the effect of the trailing shoe which would normally be reduced.

Post by **Brian** » Tue Oct 19, 2010 7:02 am

Red spring goes from anchor post to the second hole on lower shoe, black spring goes from the anchor post to the first hole in the upper shoe.

Spring on the adjuster end is correct.[/b]

JohnnyBoy · Post by **JohnnyBoy** » Tue Oct 19, 2010 10:25 pm

Thanks for that Brian, I'll change them both around when go up there with some heat to sort the cable adjustment out.

Ian · Post by **Ian** » Thu Oct 21, 2010 7:35 pm

I set mine up like this

They looked like this before

JohnnyBoy · Post by **JohnnyBoy** » Thu Oct 21, 2010 11:01 pm

Thanks for the pictures Ian, I'll be swaping my pull off springs around soon. Glad I've fitted the hold back springs like you have through the key shaped hole in the brake shoe web

Gman · Post by **Gman** » Fri Oct 22, 2010 2:29 pm

Hello to all. I don't have good brakes on my PM, no parking brake either. I have a Major for parts and the brakes on it seem to be good, has parking brake that locks in. Is it possible to remove complete brake housing by removing four bolts in picture with wire through them? Looks like it goes onto a splined shaft at this point. How about removing where brakes are attached to rear end with the bolts on outside, also has the wire run through them. Can you slide shaft and all out of rear end without goint into rear end with no worries of any inside gears dropping or slipping out of place? Thanks for any advice.

Post by **Brian** » Fri Oct 22, 2010 5:03 pm

The four bolts only hold the back plate onto the housing. What you need to do is to undo the ring around the housing where it goes onto the rear axle and try taking the housing off. If you are lucky the shaft will come out as well. If not you will have to remove the lift, Bull gears, then bull pinion shafts and housings.

Gman · Post by **Gman** » Fri Oct 22, 2010 5:36 pm

Brian wrote:The four bolts only hold the back plate onto the housing. What you need to do is to undo the ring around the housing where it goes onto the rear axle and try taking the housing off. If you are lucky the shaft will come out as well. If not you will have to remove the lift, Bull gears, then bull pinion shafts and housings.

Thanks Brian, I guess I will need to read some more in the manuals before trying this, maybe need to just go ahead and put new brake shoes on her. As to luck, well I consider myself lucky in finding this site. If not for you my PM would still be sitting and rusting of which I have repainted some although the more I have looked at her I believe she had original paint but I want to get the rust under control. Again thanks for your advice.

JohnnyBoy · Post by **JohnnyBoy** » Fri Oct 22, 2010 7:20 pm

Hi Gman, if you can get the FMD brakes to work on your PM, you won’t regret it. Even with my brake springs fitted the wrong way around and the offside cable requiring proper adjustment, they are exceptionally good brakes.

Gman · Post by **Gman** » Fri Oct 22, 2010 8:37 pm

Thanks Johnny. The Major I have for parts is a 1957 and my Power Major is 1959. I believe they are the same brakes, not positive, but I have owned the PM for 26 years and it has never had brakes going in reverse or rolling backwards but decent when going forward. I get a little nervous going backwards and most of my work I do with her is on a hill/slope. Good luck on your project.

JohnnyBoy · Post by **JohnnyBoy** » Fri Oct 22, 2010 10:02 pm

Interesting what you say. My Ferguson is the opposite… Stops dead in reverse but forwards, well let’s put it this way, I have to sneak up on the give way lines at road junctions