The Combine Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
The brakes on our 9500 combine were sticking occasionally (and would get pretty hot). We took the drum off to clean the brake area up and see if that would solve the problem. In order to move the little cylinder inside the drum (to allow the brake shoes to close enough to get the drums back on), we had to drain a bit of oil out of the system to relieve the pressure. Drums are back on and the emergency brake works fine but neither the right nor left brakes work. We can push the brake pedals right to the floor with no resistance. The operator’s manual is of no help. We contacted the JD dealer yesterday morning and he gave instructions as to how to get oil back in the lines (ran a hose from the bleed screw on the master cylinder to the bleed screw on the brake). We did that, blew brake fluid from the hose into the lines and think the lines are full of fluid but still, no pressure. Does anyone know the key to getting the brakes working again, short of taking it in to get fixed?
 

·
Registered
Joined
·
340 Posts
If you had the bleeder screw open on the brake cylinder while you had pressure from pumping the pedals, that should have let the air escape to be replaced by fluid. I don't understand running a hose between the 2 bleed screws.

Unless I'm not understanding the problem correctly,,, I'd say you have a bad master cylinder. You should get some firmness in the brake pedal regardless of whether the brakes are stuck or the lines have air in them. In other words it doesn't sound like your master cylinder is building pressure.
 

·
Registered
Joined
·
778 Posts
I've had several 9xxx machines with sticking brakes and it's almost always a seized or corroded slave cylinder. They're easy to rebuild, but even a complete new one is only about $80. But bleeding those brakes takes some time and patience. They don't bleed easy like car brakes. Set the brake shoe adjuster between the bottom of the shoes so that you can slide the drum on easily with out it hanging up on the shoes. Make sure the reservoir is always full of fluid and leave the cap off. Open both bleed screws on the slave cylinders and let gravity pull the fluid down for a few minutes. When you start to have fluid running clear at the screws with no bubbles, close one screw. Let the other one run and watch for bubbles. When there's no bubbles for awhile and just fluid, close the screw and then repeat procedure with the other brake. Then check the feel of the brake pedals. Keep bleeding and checking this way until they feel normal again. Drive the combine forward and reverse and pump the brake pedals repeatedly. This will allow the self-adjusting mechanism to put the shoes where they need to be.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #4
Problem has been fixed. The pistons in the master cylinder were seized. Moisture must have gotten behind the rubber boots at the front of the master cylinder, maybe from pressure washing. We took it apart, shined up the cylinder walls, bled the system and now both brakes work just fine.
 
1 - 4 of 4 Posts
Top