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Discussion Starter · #1 ·
I'm looking for a description of adjusting the brakes on a 1978 PK 2418. I did remove the operating rod to apply heat to the rusted fittings. It looks like the rod needs to disconnect on one or both ends to make a length adjustment. Would also like to know what to look for when making the adjustment.
 

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You have a good start with using heat yes the rod has to be disconnected but adjustments can be made at the front end only
 

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Discussion Starter · #3 ·
Yes, thanks. Still trying to get the brakes to work. I have replaced both brake bands, removed, cleaned and roughed up the drums with emery paper. They can barely keep the tractor from rolling. When engaged, the bands are snug on the drums. I'm not sure what else I can do at this point.
 

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How far down do the pedals go when you step on them? They should only go 1to 1.5" when adjusted right
 

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Discussion Starter · #5 ·
I might have more brake pedal travel than 1-1.5". I have been using the parking brake flapper as a guide. This is a 1978 2418 with the hinged metal plate that you can flip up to hold pressure on the foot pedals. Adjusted to have a small pedal play to depress and release the flapper. When I look at the brakes I see full contact between the pads and the drum.

These brakes have never worked. and by "worked" I don't mean long stopping distance. I can apply my full weight to the pedals and nothing happens from a dead-stop, in N, I cant keep the machine from moving when on a very small incline.

I have replaced the bands with re-manufactured lining (looks like automotive show lining) broken the glaze on drums with 80-grit band sander emery cloth like you would buff your leather shoes with a cloth. Everything is clean, no grease. I jacked up the tractor and confirmed there is connectivity between the final drive gear and the brake shaft (didn't open final drive) by rotating them.

The drums seem to be tapered slightly from the outside edge towards the inside edge and I suppose this is by design to help keep the band from walking out of the open end of the brake housing.

I have not been able to find documentation with as-new dimensions for the brake pad thickness or the drum diameter (other than 4") as I have been wondering if the 43-year-old drums are worn to the point that the band can't apply sufficient pressure.

In 1-st gear, level ground, engine RPM at minimum, I can stand on the brake pedals and not slow nor even hear the engine "groan". Anyway, thanks for responding. Appreciate any ideas you might have. I have alot of car and boat motor grease under my fingernails but this is this is my first tractor.

Someone else has suggested I try slipping a piece of 80-grit sand paper between the pads and the drum just to see what happens. Will try that after some lunch.
 

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Discussion Starter · #6 ·
I might have more brake pedal travel than 1-1.5". I have been using the parking brake flapper as a guide. This is a 1978 2418 with the hinged metal plate that you can flip up to hold pressure on the foot pedals. Adjusted to have a small pedal play to depress and release the flapper. When I look at the brakes I see full contact between the pads and the drum.

These brakes have never worked. and by "worked" I don't mean long stopping distance. I can apply my full weight to the pedals and nothing happens from a dead-stop, in N, I cant keep the machine from moving when on a very small incline.

I have replaced the bands with re-manufactured lining (looks like automotive show lining) broken the glaze on drums with 80-grit band sander emery cloth like you would buff your leather shoes with a cloth. Everything is clean, no grease. I jacked up the tractor and confirmed there is connectivity between the final drive gear and the brake shaft (didn't open final drive) by rotating them.

The drums seem to be tapered slightly from the outside edge towards the inside edge and I suppose this is by design to help keep the band from walking out of the open end of the brake housing.

I have not been able to find documentation with as-new dimensions for the brake pad thickness or the drum diameter (other than 4") as I have been wondering if the 43-year-old drums are worn to the point that the band can't apply sufficient pressure.

In 1-st gear, level ground, engine RPM at minimum, I can stand on the brake pedals and not slow nor even hear the engine "groan". Anyway, thanks for responding. Appreciate any ideas you might have. I have alot of car and boat motor grease under my fingernails but this is this is my first tractor.

Someone else has suggested I try slipping a piece of 80-grit sand paper between the pads and the drum just to see what happens. Will try that after some lunch.
Here's the post lunch update.

I took some 2" wide strips of 80-grit emery paper folded the strip in half so each surface has grit and slipped this in between the brake band and the brake drum. To get this sandpaper sandwich to fit in between drum and pads I needed to drop the actuator rods then reinstall them, otherwise there wasn't enough clearance. Repeated the test (above) and now in 1st gear with low RPM I can apply the brakes and hear the engine groan. I can also keep it from moving when in N.

Did I just confirm that the "new" brake bands are too thin and/or the brake drums are too worn?
 

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Discussion Starter · #7 ·
Here's the post lunch update.

I took some 2" wide strips of 80-grit emery paper folded the strip in half so each surface has grit and slipped this in between the brake band and the brake drum. To get this sandpaper sandwich to fit in between drum and pads I needed to drop the actuator rods then reinstall them, otherwise there wasn't enough clearance. Repeated the test (above) and now in 1st gear with low RPM I can apply the brakes and hear the engine groan. I can also keep it from moving when in N.

Did I just confirm that the "new" brake bands are too thin and/or the brake drums are too worn?
I just figured out what is going on with my brakes. The bands and drum are worn. I replaced the bands, looks like brand new generic pad material. They actually don't look much thicker than the old worn ones and simply replacing the bands didn't help at all. By inserting the sand paper between the pads and drums i was attempting to increase friction. What It really did was simulate thicker pads and drums that are not worn down a few thousands. The brakes started to function with the new bands, sandpaper and worn drums.

Without the sandpaper taking up the slack, the long operating rod with threaded clevis at both ends, from the pedal assembly to (12), needs to stroke more to compress the band (25) onto the under-size (from wear) drum (26). The longer stroke causes the rotating rod (12) and clevis (not shown) on the end of the long brake rod to hit the pinion tube on either side of the differential. This is preventing the band from constricting enough to apply a meaningful braking force on the drum.

Initial thoughts to reduce the stroke of the long brake rod are:
  • find new or near new drums closer to the original factory diameter
  • increase the thickness of the brake lining material
  • heat the operating arm (12) on the brake assembly and twist it to rotate it a few degrees toward the front of the tractor
  • knock out the small pin (46) that connects the rod (12), drill a new hole a few degrees that will position the rod slightly forward providing clearance between edge of (12) and the pinion tube
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I'm leaning toward trying that last one.

I searched online for an hour and while I can find multiple sources of brake lining material it all seems to be about as thick as what I have.
Seems unlikely that I will find a new or like new brake drum. Yes there are some used ones for sale on ebay and they are probably no better than what I have now.
Heating the arm to modify it to cant forward has promise and I may return to this idea depending on what I determine by drilling a new offset hole in the operating rod (12). I think there will be enough material left to insure the integrity or the part under stress and I have two old brake housing assemblies I can practice on.
 
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