Hi, I have a 1984 John Deere 510b backhoe with brake problem. After moving or driving and you go to step on brakes, pedal is soft and you can push right to floor. But when you push it a second time it is hard and brakes work. It needs two pumps to get them to work. Did not see any fluid leaks around wheels or on ground. Would like to get them working not sure what it could be.
I think those are hydraulic brakes, but they still have to be bled. You can wait to see if somebody else knows the procedure, or just wing it. MIGHT be able to bleed a little air without tools, depress the brakes very slowly and/or hold it a long time.
I think it has a equalizer, if you push both peddles and if one brake is blown, the peddles will go to floor. Is the problem with each peddle independently or together?
That older Deere has hydraulic brakes and they are wet brakes. (inside the differential /transmission housing in the oil) They may just need to be adjusted. I'm assuming your 510B could be similar to the newer C & D models. Look under at the axle housings. The axle housings look like a big funnel. Small at the wheel bearing and big where they bolt to the gear case. look for 3 sets crews per side. On my 310D they are alan screws with a lock nut over them. These set screws will be evenly placed around the perimeter of the flange. Possibly at 10, 2 and 6 o'clock. At least on my 310D, there is no blender screw. They use the transmission oil supply. If you find the set screws, let us know. Then we'll talk about setting them.
The brake bleeding procedure is from a 610 (separate dif-not transaxle), but if you think about it, how could air let the pedal go to the floor on these systems? MEK must know what he's talking about... If you do have a brake bleed screw (tee in the brake line) then DON'T open that with the engine running, the manual says to destroke the pump, so that you only deal with charge pressure, and don't injure yourself.
It seems like both pedals go to floor. When I remove lock bar between them and push both fell the same. The first time I push them they are soft but then when I push a second time the are good. When locked together. I will have to see if both pedals act the same. And let you now. Thank you for comment.
Deon, I will have to look to see. It is weird because they were working good all summer never had any problems with them. Parked it for two months and then used it to move snow and then they started act up. I'll take a look under there to see.
I looked on the JD parts catalogue. (jdpc.deere.com) You can go there to for free. Unlike mine, you do have a bleader screw on top of each brake disc. Unlike mine, you don't seem to have any adjustment at the brake disc. Like mine, you do have 2 adjustment screws at the top of each pedal inside the cab. Also, like mine, your master cylinder is supplied oil from the transmission case. Knowing this, I would: 1. check the transmission oil level. 2. make sure the oil is not contaminated with water. 3: make sure all brake lines are in good condition. 4: try bleeding the brakes (with engine running). May be a good idea to connect a rubber gas-line to the beader screw and direct the dispensed oil into a clean container jut to see what is coming out of there. If your brake disc seals are leaking and that is why you don't have brakes on the first pump, the oil will leak into the transaxle and you will not see the leak. You should be able to test the discs seal by applying strong foot pressure to the pedal for a whole minute and watch for pedal drop. On mine, the reason for the adjustment screws at the top off the pedals is,1, to match the height of the pedals and 2, to set the pedal free play. Important!!! Do not remove the two plugs on top of the master cylinder until you have checked the above. You may cause permanent damage to the check valves in the master cylinder by reinstalling the top plugs. I will explain later if you think you need to remove those plugs. I would not touch the adjustment screws on the pedals yet either. Let us know how it goes.
So this is what I found out. I suspended machine with bucket and outriggers. When you push both brake pedals together both go down to floor and need to be pumped to stop wheels. But when I seperate pedals the left pedal is normal but the right pedal goes all the way to the floor. It can be pumped up some but not solid. Once I release pedal and give throttle to spin wheels and push on it again there is no pressure and goes right to the floor. But if I push it right after pumping it up there is a little bit of pressure on it. The brake that is not working is the right side.
Ok Beeman, If the left brake works then we should be able to eliminate a few thinks. This means your master cylinder assembly is receiving oil. Look inside the cab at the plunger at the top of the right pedal for oil leak. Also look at the master cylinder connections on the outside of the cab for leaks. If no leaks are found your master cylinder is likely good as there are no internal seals to leak. Just a plunger and check valve. Follow the pressure line from the master cylinder down to the right brake connector and inspect for leaks. You may need to remove the floor. Line may be worn through from rubbing somewhere. If no leaks found, all you can do is bleed that side while watching for air. If you can get a solid oil supply and brakes still don't work you could have internal seal damage or brake is worn far enough that the disks is past the oil seal. I don't know if this can happen. I have a bit of experience with the brakes on my 310D as they were very poor when I bought the machine. Got them all fixed up after lots of studying and testing but I did not need to work on the disk and plate at the wheel. It was all adjustments and master cylinder check valve damage by the tinkerer before me. From the photos in the parts catalogue, both systems are almost the same. Let us know how it goes.
BeeMan1$, What's happening with the brake?
It's been snowing and bad weather here in ct for the past week. I need to look at it as soon as weather breaks. Will let you now what I find. Thanks
I am interested in this post as my 510 is also doing this. I have been working on a few other issues and haven't gotten to the brakes yet. If you made any progress please post an update.
Ok today I was able to work on the backhoe. I located the bleeder on top of the axle though a acess hole in the floor next to the emergency brake. Cleaned area around bleeder and bleeder itself. Bleed that brake. Had no air come out. Just oil. Bleed out about 2 cups worth. Pumped that brake and still no difference in it. That brake is still soft. It has some pressure when you pump it but is spongy. But when you hold it down it will maintain pressure it won't slowly loose it. The other brake is good still. Any help would be great.
Ok today I was able to work on the backhoe. I located the bleeder on top of the axle though a acess hole in the floor next to the emergency brake. Cleaned area around bleeder and bleeder itself. Bleed that brake. Had no air come out. Just oil. Bleed out about 2 cups worth. Pumped that brake and still no difference in it. That brake is still soft. It has some pressure when you pump it but is spongy. But when you hold it down it will maintain pressure it won't slowly loose it. The other brake is good still. Any help would be great.