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Curtis B.
Curtis B., Technician
Category: Construction and Road Equipment
Satisfied Customers: 1176
Experience:  Technican turned service manager with multiple lines of equipment and rental units.
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I have a 977 L-serial # ***** problem that I am having

Customer Question

Hi, I have a 977 L-serial # *****
The problem that I am having is with the turning/steering brakes. They work great going in reverse, however when I try to go forward they hardly work or at times will not work at all. Is there a way to adjust the brake ban? If so how do I go about making these adjustments. I was told that my machine has hydraulics brakes.
Submitted: 2 years ago.
Category: Construction and Road Equipment
Expert:  catmastertech replied 2 years ago.
Hello,You have hydraulic brake boosters, meaning you have a power assist on the brakes. This is supplied by the transmission oil pressure so, as long as you have transmission pressure you will have brake pressure.
Expert:  catmastertech replied 2 years ago.
Below is the procedure to adjust the brakes and linkage. You should only adjust the brake bands, the linkage should never need adjusting unless parts are replaced or someone else has tampered with them.
Customer: replied 2 years ago.
my transmission power to ground is good. is there a way to check that pressure though?
Expert:  catmastertech replied 2 years ago.
I am sorry, I guess I did not understand your problem. Are you saying the brakes do not apply or the steering clutches do not release? Attached is the location of the steering and brake pressures. See the image to match theses locations.H. Left steering clutch. J. Oil pump. K. Right steering clutch. L. Left brake booster. M. Right brake booster.
Expert:  catmastertech replied 2 years ago.
Here is the complete pressure chart.
Customer: replied 2 years ago.
The clutches release perfect. However the brake issue is going forwards, my machine's brakes do not want to work going forwards, but they work great going backwards...need to get them working while going forwards.
Expert:  catmastertech replied 2 years ago.
Thanks for the reply. The brake control mechanism does not have specific adjustments for forward or reverse. Uneven braking is usually due to brake band wear. The band is not perfectly round and will tend to grab better is one direction of the other. Keeping the adjustments to spec' is the only thing you can do to make them wear evenly. If all the wear adjustment is gone, then is it time for new brake bands. Have you tried adjusting the brakes?Have you verified the linkage is not worn and causing the control rod lengths to be excessive?Have the brake bands been replaced?

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