Operating with Brakes Applied - How durable are they?

[GeoHorn]

My M4700 has “wet brakes” as I presume most Kubotas do. I found myself forgetting to release the parking brakes a couple years ago so I added a flashing light on the dash/inst-panel to get my attention whenever the brakes are applied…a switch powers the flashing light. It works great.
But apparently I’ve become so accustomed to it…I ignored it today. I ran over some mesquite thorns and stopped, set the brakes and walked around inspecting tires for thorns to remove before they became too imbedded. No problem…so I was happy to get back on and resume shredding.
After a half mile I noticed the coolant temp was higher than normal…. and I smelled an odor I’ll describe as “burning plastic bags”…. and thought that perhaps the neighbor was burning trash.
After about a mile continuous shredding I re-checked the temp gauge and noticed the flashing brake-warning light.

I immediately released the brakes and continued shredding and after another mile saw it cooling back down to normal. I tested the brakes and they grabbed normally.

How durable/tough are these things anyway? Has anyone had to replace their brakes?

 

[Tropical Jack]

My neighbor has a BX. He had a very bad habit of always running at full throttle from the time he started it to the time he shut it down. He also had a very bad habit of leaving the brakes on. Understandable since we are in the mountains. A bad combination because when he stated out at full throttle, he would not notice that the brakes were on. In less than a year, he had to have the brakes replaced. He told me that it cost over $1,500 on that little tractor.

Jack

 

[DustyRusty]

They are good until they are not. When that "not" time comes, is a variable that no one will be able to tell you without inspecting the brakes first. Hook the light to a horn and that should work unless you are deaf. It is obvious that you are not looking at your gauges.

 

[The Evil Twin]

Wet brakes are extremely durable, I would assume. My knowledge only coming from the motorcycle world. Most bikes have wet clutches. Much like the brakes in our tractors, they are submerged (mostly) in oil. Their power comes more from clamping force than it does from converting friction into heat. Oil is a coolant for them, just like oil is also a coolant for engines. Anyway, point is, the elevated temperature you experience is likely a result of the added load to the engine and not from the brakes getting hot. I've done it a time or three (new to tractors) and after digging into it I'm not concerned. Now, day after day and hours upon hours will wear the friction plates. But occasionally won't impact them significantly.

 

[leveraddict]

Why would any tractor move without at least some hint that the parking brakes are on? Isnt there some noticeable drag or loss of power? My tractor won't move with the parking brake applied not to mention the loud HST whine if you try! Is there an adjustment?

 

[GeoHorn]

They are good until they are not. When that "not" time comes, is a variable that no one will be able to tell you without inspecting the brakes first. Hook the light to a horn and that should work unless you are deaf. It is obvious that you are not looking at your gauges.

Dusty, it was ”looking at my gauges” that caught my attention. The engine temp gauge was running just-above it’s usual that provoked me to think about it. The unfortunate thing about my adding a brake warning-light is that location can be hidden by the steering wheel spoke at times.
I am considering adding a son-alert.

Why would any tractor move without at least some hint that the parking brakes are on? Isnt there some noticeable drag or loss of power? My tractor won't move with the parking brake applied not to mention the loud HST whine if you try! Is there an adjustment?

Lever, my tractor is a utility model “M4700” with about 50 HP driving a Gear-Drive transmission….so Since I was shredding some pretty tall brush I was in a lower gear and spinning the engine at PTO speed meant that the applied-brakes were unnoticeable to that much generated power.

Evil-Twin, I agree…the additional engine load was the cause of coolant temperature increase…. BUT, “clamping force” is not unrelated to heat. Brake application (clamping force) creates friction and that transforms kinetic energy to thermal (heat) energy…and is how brakes work.

I was shredding the outer-sides of my 3400’ X 150’ turf runway which I normally keep about 15’ of each side un-mown to give distinction to the center operating-area. It had grown almost fence-height high over the last two years and I was shredding/clearing a line immediately adjacent to the fence to aid fence-maintenance. Since I was shredding only inches from the fence I was concentrating on not. “taking-out” the fence with the FEL and/or the rotary-cutter…. so I’d already made one 3400’-pass westbound and was about halfway back on the eastbound side before I realized the brakes were applied… about a mile of brake-friction and heat.

I also wonder what that does to transmission-oil (SUDT2) which I’d recently changed in a 600 hr service.

 

[Motion]

I like the idea of a flashing light on the instrument panel.

 

[hagrid]

The odor troubles me. And I don't mean the fart I just ripped.

If you have strainer on the suction side of your hydraulic pump it might be worthwhile to check it, provided the transmission and the hydraulic circuit share a common sump.

 

[The Evil Twin]

Evil-Twin, I agree…the additional engine load was the cause of coolant temperature increase…. BUT, “clamping force” is not unrelated to heat. Brake application (clamping force) creates friction and that transforms kinetic energy to thermal (heat) energy…and is how brakes work.

I also wonder what that does to transmission-oil (SUDT2) which I’d recently changed in a 600 hr service.

I oversimplified how wet brakes work. Of course they still convert energy. My point is that it is over multiple steel rings and friction rings. Not like a disk or drum. They stand up to a lot more abuse. Heat is the enemy and wet brakes run in a coolant. I've got a clutch pack ( same principle) around here somewhere that was beat up for 20000 race miles. The steels are blued in some spots but otherwise it's still serviceable.
I wouldn't worry about it unless they seem less effective.

 

[GeoHorn]

I like the idea of a flashing light on the instrument panel.

Here’s where I described the installation (with pics): https://www.orangetractortalks.com/...ake-reminder-caution-lamp-installation.48021/

The odor troubles me. And I don't mean the fart I just ripped.

If you have strainer on the suction side of your hydraulic pump it might be worthwhile to check it, provided the transmission and the hydraulic circuit share a common sump.

Yes, it’s a gear-drive tractor… SUDT2 common sump for tranny and hyds. Dual spin on filters w/magnets so if anything was generated I’m thinking it was filtered out. I might take a hyd oil sample.

 

[BobInSD]

Geo,

I never had a tractor where the parking brakes worked before and I also struggle to remember this at times. I'm trying to develop the habit of stomping (or a least tapping) the brakes as I advance the throttle.

I like the idea of a flashing light on the instrument panel.

"Me too". Any chance OP could post a schematic or drawing? Do our tractors have brake lights? With brake lights I could figure out how to do it. Not sure how much it would help, since I'm always startled after working for awhile at night and then noticing the (always illuminated) flasher button. Scares me every time.

 

[ve9aa]

I guess I'll count myself lucky that the BX doesn't have the power to pull away with the brake on !
(one time a baby tractor is an advantage)

 

[GeoHorn]

Geo,

I never had a tractor where the parking brakes worked before and I also struggle to remember this at times. I'm trying to develop the habit of stomping (or a least tapping) the brakes as I advance the throttle.



"Me too". Any chance OP could post a schematic or drawing? Do our tractors have brake lights? With brake lights I could figure out how to do it. Not sure how much it would help, since I'm always startled after working for awhile at night and then noticing the (always illuminated) flasher button. Scares me every time.

I posted a link to the thread where I developed/installed the flashing brake-applied light and also where to purchase the flashing L.E.D. (see post 10 above).

I simply welded an angle-bracket onto a support which holds a normally open (NO) push-switch. Pulling the locking-lever which holds the brakes in the “applied” position …the lever also depresses the switch which activates (energizes) the LED lamp with 12V from the ignition switch.

Here’s a short video of the flashing lamp: https://photos.google.com/share/AF1...?key=eDdtaERBNUZFUGdsb3pNbTRpMWtCSWo5bWNOTGVR