Brake Repair Finished

rock_breaker

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Dec 31, 2010
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The left brake on my Branson 3510 tractor was severely dragging, so much so that the tractor would stop on a down grade when just the clutch pedal was pushed. The parts book shows 4 friction disks sand-witched between 4 steel plates. Pressure is applied by a pressure plate rotated on 4 steel balls by a cam lever assembly and ultimately linkage to the brake pedal. The cam lever shaft is oil sealed and only rotates about 15`. The brakes run in transmission/hydraulic oil.

Disassembly and examination did not reveal any particular problem, the friction disks were all 0.195" thick without any real sign of warping but on my plane table one disk had about 0.005" bow, the rest up to 0.0015" in one spot. The steel disks are 0.125" thick with a maximum bow of 0.0015". It was easy to overlook the brake lock system when getting and on the tractor to move things around and this I believe is the cause of the distortion.

Temporary reassembly with 0.012" shims between the cover and the housing let the axle turn freely so I decided to make a thinner steel plate. I found a chunk on 0.125" plate in my outside storage (junk pile) Thinking I could clean the rust of on the mill and rotary table I encountered the first of several problems: no wheel on the rotation leadscrew. problem # 2 was the centering plug used to center the RT under the mill quill was to long. My Clausing lathe cured both of these problems. The rust was removed from both sides of the plate and the thinning had started with a fly cutter but it was to rough so a 3" 4 cutter face mill was used with some what better results but the light cut caused work hardening. A piece of weathered 3/4" [plywood was faced off on the faceplate and a thicknes of 0.109" was achieved using a brazed carbide cutter that has seen better days.

The outside diameter of the steel plate is used to hold the plate in proper position but with a yoke on the perimeter to prevent the plate from turning when brakes were applied. The correct diameter and the shape of the yoke was accomplished on the RT and the mill. This work was done prior to working on the lathe.

The sharp corners wear filed off and the brake reassembled, the transmission refilled with oil and the tractor taken off the blocks. With the brush hog mower attached 1.25 miles of weeds were cut along the property line without any heat build up on either brake.

At a minimum I estimate my shop saved $ 280.00 if the steel plates cost $35.00 like the friction disk. This problem was posted earlier and the comments and guidance from the members have made this possible. Thanks!

Have a good day
Rays
 
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