8n Brakes

[Mike in MT]

So running into an issue with the left (driver's side) brake on my 52 8N.

Short version, even after replacing the seals, and brake shoes, the left brake isn't functioning well (won't really lock up the tire, and really have to stand on it to stop the tractor).

Longer version in case there is something else going on.

Have had this tractor for a long time (in family since new), left brake has always worked great. Had to replace the right axle due to a worn hub/axle about 6 months ago. When doing this to set the preload correctly I had to add several shims to get the end play correct. All was good for a couple of months, but then one day, I went to use tractor and when I stepped on the left brake, it had almost no braking (wouldn't stop the tractor). There was no gradual change like oil had been building up on brake pads or anything like that, it just didn't seem to stop the tractor (motion was pretty much normal, the pedal didn't go to the running board or anything like that). So I decided to take a look, and I noticed the left hub was very loose. So I replaced the hub, and took a look, and could tell there was oil leaking from the inner seal, but the pads didn't seem to have oil on them. When I put it back together, the brake was, as expected still the same.

A couple days ago, I finally got the parts to replace the seals (inner & outer), as well as the brake shoes. I cleaned out all the oil, replaced all the parts and put it back together (including adjusting the brake so that it drags slightly, then backed off a little bit) expecting a fully functional left brake, however, it was only marginally better than before. I can, if I basically stand on it, get the tractor to stop. but it won't lock the wheel up.

I'm at a loss as to what could be going on, so as always, any help would be appreciated.

Mike

 

[Bruce(OR)]

A few things.
The drums are nicely polished over after 50 plus years and should have either been turned or roughed up to get the new
shoes to seat.
The NTSB outlawed brake shoe arc machines a very long time ago. So now when you install brake shoes, the arc of the
show is such that only the ends contact the drum for a very long time until they eventually wear down.
You took it apart and looked at the brake shoes. Did you notice the center of the shoe, lengthwise is virtually
untouched? That is because both ends need to wear down until the shoe makes better contact with the drum.
Can you speed that process up?
You Betch'a!
Get that bassard file out and file down the leading and trail edges about 10-15 percent.
Brakes should work a bit better with just that. Moere? Get those drums turned and file the shoes.
More? Buy a new machine. I did.
Merry Christmas!!

 

[jimtrs]

(quoted from post at 11:47:53 12/22/23) So running into an issue with the left (driver's side) brake on my 52 8N

Short version:
Follow Bruce's reply

Longer version:
Barrel wear and bellmouth wear contribute heavily to the problem you're describing. Barrel wear is common on these old Fords, as the drums may have never been trued, and you see 70 + years of wear. Keep in mind that braking on these old Fords only gets so good. Though, when properly done can be pretty good. Should help you turn, should lock up the wheel, should hold you on a hill. All that applies to either brake individually, or both brakes together

Get the drums turned.

 

[Mike in MT]

Thanks for the info I'll see if I can find a place that still turns drums and go from there.

 

[Mike in MT]

Thanks for the detailed info. The pictures were helpful.

 

[JMOR]

(quoted from post at 11:34:02 12/23/23) Thanks for the detailed info. The pictures were helpful.

 

[Eman85]

(quoted from post at 08:32:53 12/23/23) Thanks for the info I'll see if I can find a place that still turns drums and go from there.

Turning the drums actually makes it worse. If you make the drum larger by turning you reduce the contact area of the shoe. Remove a drum and place 1 shoe in and rock it and you will see how much contact area you have. Stopping your tractor from a couple of MPH should not be too hard. Clean shoes a sanded out drum and properly installed brakes should do it. My 51 leaked and ruined the shoes. Cleaned it all up sanded the drums and I can lock the left brake on my gravel drive easily tractor stops fine. I didn't arc the shoes just knocked off the edge with sandpaper and sanded the drums after a good cleaning.

 

[Dean]

Bingo.

Additionally, brake drums on vintage Ford tractors are steel, rather than cast iron (unreliable aftermarket replacement drums are cast iron and easily crack). Such drums cannot be cost-effectively turned
on conventional, still available, brake drum lathes but should be turned on brake drum grinders. Seen one of these in the last 50 years? Won't comment about the inability to find any shop that can cam-
grind new shoes to fit drums that have been turned beyond saying that both brake drum grinders and cam grinding machines vanished at about the same time with the advent of disc brakes.

If drums are scored (unlikely due to brass rivets and steel drums) or (more likely) rusted beyond service life, source good used drums from a salvave yard.

 

[Hobo,NC]

(quoted from post at 23:41:56 12/23/23) Bingo.

Additionally, brake drums on vintage Ford tractors are steel, rather than cast iron (unreliable aftermarket replacement drums are cast iron and easily crack). Such drums cannot be cost-effectively turned
on conventional, still available, brake drum lathes but should be turned on brake drum grinders. Seen one of these in the last 50 years? Won't comment about the inability to find any shop that can cam-
grind new shoes to fit drums that have been turned beyond saying that both brake drum grinders and cam grinding machines vanished at about the same time with the advent of disc brakes.


If drums are scored (unlikely due to brass rivets and steel drums) or (more likely) rusted beyond service life, source good used drums from a salvave yard.

You can turn them on a modern brake lathe but you got to know what you are doing are you will turn the drum into two pieces. You will have to use a different tool and insert I use one for my metal lathe. You may never achieve a perfect Finnish on a worn drum but you can recover the surface on most to about 75% plus. I have done quite a few and do turn all I work on that's unless its close to perfect. The last N I did a few weeks ago the drums looked like new I left them alone. The drums were slick and shined like a mirror I believe it was a tractor that was restored by N complete. No break in needed it would lock the wheels up on any surface.

The bad not any garage that has a brake lathe can do a good job as dean pointed out these drums are a different animal. The tooling to chuck them up in a brake lathe is different you will need a truck centering cone. I gave $600 for my truck set most pass and ship the job out.

You can ruff up the drum and grind on the shoe till ell freezes over uneven surface of the drum is where most all issues are.