Several thousand $ brake pad!

[Black Forest]

Gentlemen here is a brake pad for my Polaris Ranger EV that cost several thousand dollars! Yep, just made out of brass not gold. This parking brake pad is what prompted me to get off my butt and convert my mill to CNC so I could machine this pad. The parking brake pads are not replaceable. You have to replace the entire parking brake assembly. It is not possible to buy just the pads only the whole assembly at over $200! Absurd design. It is a very wasteful design. So what does any self-respecting home shop machinist do you ask? He tools up in order to make said brake pad himself of course! Yes I know I could have used a rotary table to make the part on a manual mill but my wife didn't know that!!!!!!! It took me a lot of time to convert my mill to CNC and a lot of learning on how to do the conversion and learn how to actually make the program to mill it. Countless questions on here and the Centroid forum, etc., etc.. But I showed the Polaris company didn't I.

They won't be messing with me. The brass actually doesn't work well as the brake pad. Too slippery. Please don't tell my wife. The brake assembly is a disk brake design with the disk mounted on the drive shaft coming out of the transmission with the "calipers" next to it. If I tighten the brake cable enough to actually hold the buggy on a hill the brake squeals when driving. No squeal no holding power. Now I have to figure out how to fix this problem. Any suggestions on what machine I need to buy to solve this problem?

[Noitoen]

My little 35 year old Suzuki Samurai jeep uses as a parking brake a drum on the rear drive shaft as well. It works ok but there is a conversion kit with disk and cable operated caliper. Maybe the secret is how the caliper itself is made.

https://www.jimnybits.com/suzuki-sam...brake-kit.html

[boslab]

Can’t answer that but isn’t the pad covered with friction material (though I was under the misapprehension that parking brakes were band brakes, ) brass is a bearing material, I was thinking low friction, would iron be better? Or get a truck pad and machine to the shape you need?, either way well done on the mill, there’s miles left in the old noodle yet.
mark

[Black Forest]

The caliper part of the parking brake used three ball bearings to apply pressure to the brake pads. They are arranged in a triangular pattern. There are dimples in the lever and back plate that allow the balls to retract into the dimples and release the pressure. When the lever is pulled on by the brake cable the balls roll out of the depression in the ramped dimple and apply pressure. Not a bad system but a little finicky. I thought about designing a new caliper system using hydraulic bike brakes. Or build my own caliper.

[Black Forest]

Can’t answer that but isn’t the pad covered with friction material (though I was under the misapprehension that parking brakes were band brakes, ) brass is a bearing material, I was thinking low friction, would iron be better? Or get a truck pad and machine to the shape you need?, either way well done on the mill, there’s miles left in the old noodle yet.
mark

Mark I know that brass is slippery but it is real shiny and pretty! Doesn't hold for crap but is pretty.

[Noitoen]

If you look at the caliper I posted just for reference you will see that it's just like the a cable operated bike caliper. I think hydraulic for parking brake is not a good idea. My campervan has disc brakes on the rear wheels and drum brakes inside the discs for the parking brake just like Mercedes used to do. Some cars with rear disc brakes have a lever actuated system on the same hydraulic caliper for the parking brake system

[RSG]

Several thousand you say???? Seems about right! 😁 That's how I justified my entire machine shop after I fixed a broke item of the wifes! 😀

Nice work, but I'd still have used the Rotab 😉

[Black Forest]

Several thousand you say???? Seems about right! 😁 That's how I justified my entire machine shop after I fixed a broke item of the wifes! 😀

Nice work, but I'd still have used the Rotab 😉

I don't have a rotary table. I have a nice indexing table but that wouldn't work. So the question is, do I buy a rotary table for 400€ or upgrade my mill to CNC for lots more......duh..no question, upgrade the mill!

[Toolguy]

Congrats on the newly CNC'd mill and new skills to use it! Have you gone through the first 9 million yet?

It seems to me that a disc brake pad should have some high friction material on it, the same as for stopping the car. If the caliper doesn't allow room to rivet something to the brass, maybe you could design and make your own caliper? It could be mechanical or hydraulic. If hydraulic, it could use a small hand pump to activate it, with a release knob like a bottle jack. Lots of different possibilities.

[Willy]

I salute you for being able to bypass the Polaris part$ dept. and fabricate your own. Doing the CNC upgrade and the knowledge you gained is another feather in your cap that will never be lost.
Well maybe in a few years when you can't remember where you left the mill or what it's for, but that's another story.

Back in the day largish trucks still relied on a drum brake fastened to the drive shaft, usually near the transmission, as the primary parking brake. These were OK on flat land but were woefully inadequate when parked on a hill, especially when heavily loaded. Another issue these systems had was that on slippery slopes only the rear axle was locked, well kind of for the most part.

A company emerged to address that situation, Mico, or as I always refereed to them, Mico-Lock.
The Mico-Lock system uses a one way manually operated check valve to lock all wheels solid. I have used the Lever Lock style extensively and have never had an issue.

In operation when one has to park, all one needs to do to activate the system is make a full brake application, lift the lever to lock system pressure. When ready to move all that needs to be done to release brake system pressure is to move the lever in the down position. Always a bonus to have all wheels locked when on a slippery slope.

I see that they must now be under ZF umbrella, as you can see from the link below they now have a much broader range of coverage than what I knew them for, but having used the Lever Lock system in a wide variety of applications I can't say enough as to their effectiveness.

https://www.mico.com/products/brake-locks

[chipmaker4130]

Willy, the weak spot for those is that even a tiny leak or seep past a seal will let everything loose, even a severe temperature change can be a problem. I used to fly a $30 million jet that used something similar for a parking brake. Difference there was that system included an accumulator that could compensate for significant fluid loss. Fortunately, we never 'parked' long on a hill!

[jmm03]

FYI, I have used this place to fab an unobtainable brake for a Bridgeport type mill: https://www.allfrictions.com/ Jim

[Willy]

Willy, the weak spot for those is that even a tiny leak or seep past a seal will let everything loose. I used to fly a $30 million jet that used something similar for a parking brake. Difference there was that system included an accumulator that could compensate for significant fluid loss. Fortunately, we never 'parked' long on a hill!

I totally agree.
However it goes without saying that the hydraulic system should be in good operating condition, if you've got leaking wheel cylinders that vehicle should not be roadworthy in the first place. The Mico Lock system should always be used in conjunction with the redundant mechanical system as backup just as standard operational procedure.

I was a little apprehensive at first when using these on fuel trucks using hydraulic brakes, don't need 3,,000 gals. of gas going down the hill while you're around the corner and out of view of the truck! However after seeing these systems used without incident in large fleets I can attest to their reliability.
The system does work well, but in mission critical scenarios it is important to not only adhere to strict vehicle maintenance schedules but also to have a plan B.
That plan B for me at least was to use wheel chocks. Not that hey were ever required, in my experience at least.

[Dan Dubeau]

I've made quite a lot of expensive parts like that over the years. The good thing is that everything after that is cheap/free .

I wonder if you could just machine down a brake pad from another application? Make sure to have a vacuum on it at all times when machining the friction material, but I'd give that a try

[wdtom]

I like the idea someone had of machining a pad out of a disc brake pad that is close to the right thickness. They are cheap.