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Bomag 100 AD stops travel after warm

Zach1881

New Member
Joined
Mar 24, 2020
Messages
4
Location
97103
I have a Bomag 100 AD that will randomly stop traveling after about 10 minutes of solid use. It only has about 1,000 hours on it. The drums continue to vibrate and the parking brake light does not come on.. help??
 

mg2361

Senior Member
Joined
Jul 5, 2016
Messages
5,845
Location
Pennsylvania
Occupation
Equipment Mechanic
Does it stop immediately like the brake is applied when it happens? Does it sound like it wants to drive against the brake? The travel linkage is not worn or loose?
 

omal1989

Member
Joined
Feb 27, 2019
Messages
10
Location
Ireland
I have a similar problem with a bomag ad3 , when hot , 20-30mins or so it’s almost like it looses pressure on the oil , if you vibrate yourself into a rut it won’t pull itself out of it , any uphill resistance against the machine driving will stop it suddenly ,
 

omal1989

Member
Joined
Feb 27, 2019
Messages
10
Location
Ireland
Both forward and reverse? Has charge pressure been checked?
Yes both forward and reverse . Pressure was checked as far as I am aware , bad memory now , brakes checked too , once it cools down it will run ok again until warm ! Sorry about the extremely late reply !!! I couldn’t remember my log in info
 

dave130b

New Member
Joined
May 30, 2024
Messages
2
Location
Ireland
I have a similar problem with a bomag ad3 , when hot , 20-30mins or so it’s almost like it looses pressure on the oil , if you vibrate yourself into a rut it won’t pull itself out of it , any uphill resistance against the machine driving will stop it suddenly ,
Hi Omal,
I have same roller as yours and same problem can you please let me know what the issue was with your one. Any help greatly appreciated thank you
 
Joined
Oct 11, 2024
Messages
7
Location
06877
MG2361, I have the same problem as Omal and Zach. Mine definitely has to do with the brakes. You can hear them dragging. It is almost like the brake solinoid can't hold the valve open when it gets warm. Can the brakes be manually adjusted? What was the charge pressure you were referring to above? Any help might fix all our issues.
 

mg2361

Senior Member
Joined
Jul 5, 2016
Messages
5,845
Location
Pennsylvania
Occupation
Equipment Mechanic
Welcome to HEF PreferredSteve;)!

MG2361, I have the same problem as Omal and Zach. Mine definitely has to do with the brakes. You can hear them dragging. It is almost like the brake solinoid can't hold the valve open when it gets warm. Can the brakes be manually adjusted? What was the charge pressure you were referring to above? Any help might fix all our issues.
No, they cannot be adjusted. Your issue is most likely electrical.

Is there voltage getting to the solenoid? For the brake to release, the controller has to see that you are in the seat (seat switch), then when you pull the travel lever towards you (out of the park position) so you can move it forward or rearward, the switch there tells the controller to release the brake.

Charge pressure is what releases the brake. The brake is spring applied and hydraulically released.
 
Joined
Oct 11, 2024
Messages
7
Location
06877
mg2361, Thank you for your quick response. I assume the seat switch is the seat belt? If I install a jumper from the battery to the solenoid after removing the original wire, should this act as a test on the solenoid? If that works, and the brakes still drag, how do I test the charge pressure?
Thank you for your input.
 

Vetech63

Senior Member
Joined
Aug 10, 2016
Messages
6,888
Location
Oklahoma
I assume the seat switch is the seat belt?
The seat switch is actually mounted within or outside underneath the seat cushion.
If I install a jumper from the battery to the solenoid after removing the original wire, should this act as a test on the solenoid?
A 12 volt test light will tell you if you have power to the park brake solenoid. You could also measure with a volt/ multimeter.
how do I test the charge pressure?
There is a removable panel, right side underfloor level. There should be marked test ports there and charge pressure will be one of them.
 
Joined
Oct 11, 2024
Messages
7
Location
06877
Is this a hydraulic charge pressure? What type of gauge will I need? I am heading to my shop to review all your suggestions as it is a nice day.
So it sounds like there are no adjustments to the system. Just verification that original systems are functioning?

Thank you again for your help! It seems that this is a regular problem from all the posts with these machines.
 

Vetech63

Senior Member
Joined
Aug 10, 2016
Messages
6,888
Location
Oklahoma
Is this a hydraulic charge pressure?
Yes
What type of gauge will I need?
0-600 psi for charge pressure only. Don't use that gauge for any other pressure measurement. I don't remember the exact spec on the charge pressure but it seems like it was in the 400's. The charge pressure should remain steady at idle and full throttle. It should remain steady when you engage forward or reverse. If it drops when you try to move the machine, then you are losing pressure in the travel loop which is going to case drain. That in turn will let the brake springs start to apply because of the pressure loss.
Just verification that original systems are functioning?
Correct
 
Joined
Oct 11, 2024
Messages
7
Location
06877
Thank you for your help. You are very clear in your descriptions. I am leaving for my shop and the automotive supply house to get this gauge. I will probably check out the electrical portion first, and if good, verify pressure.
If the solenoid is defective, do you know where to purchase one?
You have been a great help. Thank you

Steve
 

mg2361

Senior Member
Joined
Jul 5, 2016
Messages
5,845
Location
Pennsylvania
Occupation
Equipment Mechanic
On the BW100AD-4, the charge pressure test port is in the fitting coming out of the filter housing under the front hood.

If you supply a machine serial number, I can confirm that. The serial should begin with either 1018, or 8618, and be 12 digits long.
 
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