RXV Motor Brake Symptoms & Temporary Fix

[tracetrimble]

I'm on my probably 4th motor brake on my 2009 RXV. It was problem free until about 3 years ago, and now it eats a brake about every 9 months. Last time it failed, I replaced the switches and sensors in both pedals, bypassed the run plug, and checked all the wiring in between. Didn't find any issues, but here we are again...

I really like everything else about the cart, and have it set up really well for my uses. I really don't want to get rid of it, but I'm tired of this crap with the motor brake.

The previous times it has failed, I noticed the cart being a little sluggish for a short time (like 1 mile), and then I'd usually start noticing the brake smell, and it was a goner. Sometimes it has failed with no burning brake smell.

This time, when I notice the cart being sluggish when taking off from a dead stop, I stop, push the brake pedal all the way to the floor (which cycles the brake switch), and then try to go again. Anywhere from 1 to 6 times doing this, and it will drive normally, coasting when you let off of the accelerator rather than coming to a stop quickly. I have also noticed a 'twittering' noise sometimes when the cart is being sluggish, and it seems like there is a frequency in the signal to the brake. The sluggishness is also more prevalent when I can hear this noise. Other times it will be less sluggish but not normal, and I can't hear the noise (but my hearing isn't awesome).

Anyway, in all the discussions I've read about these stupid brakes, I haven't heard the noise or mashing the brake to the floor to fix it mentioned, so I wanted to put it out there. Any ideas?

[Volt_Ampere]

Sounds like the brake is engaging when it shouldn't. The mechanical brake should not engage except when you come to a stop. Maybe the connector is bad that connects to the brake. It's designed so if you lose power, the brake goes on.

[tracetrimble]

Maybe, but why would pumping the brake pedal fix it?

[Volt_Ampere]

You need an RXV expert for this. I have worked on a few but not with this problem.

[nickdalzell1]

How much do you use the brake pedal? The more you stop with that the shorter the lifespan of the e-brakes in my experience. The cars should sort of stop themselves via regen without you needing to stomp the brake pedal or even use it most of the time. These brakes are designed to fail. It's never an if, it's a when. The difference is what you can do to extend this lifespan. Same goes for the chargers these come with.

How are your batteries? What age are they? Water levels? Low voltage = heat and that can also EOL a brake (and potentially a controller)

How much are you tightening the bolts when replacing one? Overtightening them can also ruin the new one. There's also an opinion that the Danaher cars (which your '09 is) are supposed to use a different e-brake from the Curtis ones. But I've never experienced that myself.

[tracetrimble]

I think I'm pretty light on the brakes. I do actually coast to a stop whenever possible.

Batteries are 5 yrs old now and losing some range recently, but they were in better shape the last 3-4 times it ate a brake since 2018. I'm decent about checking the water levels. Abandoned the silly watering system it came with a long time ago, and check/refill them manually.

I do a lot of wrenching, and I think I have a pretty good feel for how tight a bolt of a certain size should be. I read about overtorque issues early on, and have been conscious of that when replacing the brake. I actually own 3 torque wrenches, but didn't use one in the middle of the pasture/road/etc where the fncking thing stranded itself. LOL

The other thing is, a new brake fixes it for a few months, so it has to be cooking the coil in the brake... ?

[nickdalzell1]

How hot is the motor getting and how long do you drive it? I've heard stories of folks having issues after 30 minutes of non-stop driving. Back when the RXV launched, it quickly gained popularity around here, and many folks thought it'd be a great idea to test drive them 20 miles from Owensboro to Beech Grove, KY and many failed about halfway from a burned up brake AND motor. For a short time, their popularity here decreased because many love driving on backroads and use them in place of a regular passenger car. Since the Curtis variants, this issue has been resolved.

Where are you sourcing your brakes? Amazon? Ebay? The OEM part number is 617766. It's $250. If you're paying considerably less that might be your issue. You get what you pay for.

[tracetrimble]

I have bought a $250 OEM brake from golfcartking.com, and a couple $100 10LOL brakes from Amazon. The OEM brake actually failed sooner than the knockoffs!

I usually don't drive it more than about 10 mi between charges, and almost never more than 5 mi in a stretch. I haven't felt the motor for heat after driving it.

[Volt_Ampere]

Something is wrong if the brake doesn't last the life of the cart. It's not intended to stop the cart! It's a "parking brake".

[tracetrimble]

Something is definitely wrong with most/all RXVs.