Bomag 120-AD3 Brake problem

[ASPHALT04]

I have a Bomag 120 that wont release the brakes. So far the e-stop switch; ignition; forward/rev control; and seat switches have checked out fine.
If I put power to solenoid the system works. I just can't find the relays to test or even know if they are the problem. I got about 6 unfruitfull hrs in this already:Pointhead

[Countryboy]

Welcome to Heavy Equipment Forums ASPHALT04! :drinkup

[stevinmonteur]

I have a Bomag 120 that wont release the brakes. So far the e-stop switch; ignition; forward/rev control; and seat switches have checked out fine.
If I put power to solenoid the system works. I just can't find the relays to test or even know if they are the problem. I got about 6 unfruitfull hrs in this already:Pointhead

check out the circuit-board on the left side of the steering column.
take it out ( wrench 13 mm ) ,there are leds on it so you can check if it is working. problem could be the circuit-board or the electric connector/wiring below it.

marco

[ASPHALT04]

Thanks, I actually figured out the problem a couple days ago........After testing everthing I found a bad connection the the seat switch jumper.......I fixed that and it still didn't change the power to the brake soleniod. I ended rooting thru the book somemore and tested power to all the relays and 1 didn't have power, then it hit me that that relay got power from the alternator,,,,DUH, start the engine. Started it up and everthing works. The problem was actually the seat switch jumper the whole time and I went so much deeper into than I really needed too.
Kind of like the old saying " Turn on the gas dummy".

[ASPHALT04]

Anyone know a good place to find the poly-urethane scaper material for a roller? There has to be something cheaper than buying from bomag.

[ASPHALT04]

I guess I should have just called this thread Bomag 120 AD-3.

After getting my brake troubles solved and other repairs done the roller has sat in the shop in the same place for about 2 weeks without moving. I went in the shop about 3 days ago to find ,out of the blue, a hydralic puddle about 3' in diameter. :beatsme After some inspection, I found that the front drive motor had started leaking.

I pulled it off yesterday and took it to the bomag dealer for them to give me an opinion on it. They have to send it out to be looked at and I am awaiting an estimate on it. The real kicker is that bomag want $4k for a new one!!:eek: I am hoping al it needs is a seal kit!!

Anyone else ever run into this with a poclain motor?? :Pointhead

[ASPHALT04]

Well I'll just keep adding here myself LOL!

Bad news on hydraulic motor......unrebuildable. The brake trouble I was having caused massive internal damage to motor. Not great but better I came across a brand new motor of $2K.
The Bomag dealer wants me to show them where I found the connection problem and how I fixed it because they have had 1/2 dozen with same problem in past year and had to replace the drive motors. If I had been a bit quicker to replace the factory connector with a $1 butt splice I wouldn't be spending $2K and or posting in this thread!!:Banghead

[Ryanrb25]

so the brake being stuck on while trying to move the thing caused the motor to self distruct because it was kind of working against itself?

[MrElectric03]

My shop used to be a BOMAG dealer and yes the parts are extremely overpriced....like most parts out of Germany.

[seankenny10]

i have a bomag 80 roller which wont rev up completly