D8H brakes lock up when hot

Bart, the D8H tractor doesn't apply brakeing from the steering levers as the D8k does.
If you are experiancing Brake Band Lockup. I reccomend you lift the fuel tank, and the steering clutch covers. Then check the lube hoses to the brake bands. They are prone to braking and if they are broken and you change them the problem could be solved.
Later Bob

[quote="bob"]Bart, the D8H tractor doesn't apply brakeing from the steering levers as the D8k does.
If you are experiancing Brake Band Lockup. I reccomend you lift the fuel tank, and the steering clutch covers. Then check the lube hoses to the brake bands. They are prone to braking and if they are broken and you change them the problem could be solved.
Later Bob[/quote]

the book does not show or reference any lube hoses for the brake bands. do you have any pics or parts manual pages that might show them? this cat is a 2 hour drive down some nasty steep rough dirt roads so i like to have the parts I need when I get there>
are these "CAT" lines or fabricated in the field?
also am I correct in assuming these break internally as there is no river of oil following this cat?
many thanks for your input.
Bart

There are't any cooling lines on D8H's, you need to check your brake adjustment. Also check your linkage s to see if everything moves freely, that your pedal returns to the fully released position after brake application. Check your park brake lock lever, make sure that is not interfering with the brake operation. If everything moves freely as it should, your brakes are set too tight. If you know where the adjuster is, at the rear of the steering clutch cover, tighten the adjuster, then back it off 9 clicks. (a turn and a half). Just in case you don't know, that little cover at the rear has three bolts. Good luck.

You didn't mention the Serial No. of your machine. My experience is only with machines from the 18000-s up. They have oil lines delivering oil to the brake linings; don't know about the earlier machines.

If your linkage is good, then the rest of the brake system is in the covers or underneath them. Check your linkage carefully; worn pin or clevis, bent rod. You'll probably have to shovel out some debris before you can figure that out.

If you pull the fuel tank, keep track of your bolts and all the hardware therewith. You can't believe how many guys bolt the tanks back down using the wrong hardware and run the bolts up through the bottom of the tank. You don't need to be welding a hole in your fuel tank on top of everything else.

[quote="bob"]Bart, the D8H tractor doesn't apply brakeing from the steering levers as the D8k does.
If you are experiancing Brake Band Lockup. I reccomend you lift the fuel tank, and the steering clutch covers. Then check the lube hoses to the brake bands. They are prone to braking and if they are broken and you change them the problem could be solved.
Later Bob[/quote]

the book does not show or reference any lube hoses for the brake bands. do you have any pics or parts manual pages that might show them? this cat is a 2 hour drive down some nasty steep rough dirt roads so i like to have the parts I need when I get there>
are these "CAT" lines or fabricated in the field?
also am I correct in assuming these break internally as there is no river of oil following this cat?
many thanks for your input.
Bart

[quote="mike walsh"]you didn't mention the serial no. Of your machine. My experience is only with machines from the 18000-s up. They have oil lines delivering oil to the brake shoes; don't know about the earlier machines.

If your linkage is good, then the rest of the brake system is in the covers or underneath them. Check your linkage carefully; worn pin or clevis, bent rod. You'll probably have to shovel out some debris before you can figure that out.

If you pull the fuel tank, keep track of your bolts and all the hardware therewith. You can't believe how many guys bolt the tanks back down using the wrong hardware and run the bolts up through the bottom of the tank. You don't need to be welding a hole in your fuel tank on top of everything else.[/quote]

s/n d8h 46a14080

Sorry. Can't help you with that one. I would be surprised though if it did not have oil lines running to the top of the brake assembly.

I can relate to what Bob is saying as the steel braid on the lines I've observed tends to be heavily stressed and frayed when the machine has a lot of hours on it. We change them out when we're working in the bevel gear compartment to avoid the adventure you're now facing.

The practical problem you're facing is you're not likely to stop at the hose. That means working 2 hours from the shop. If it were me, I'd drive it up out of the hole and load it up before I pulled the brake covers. Catsilver posted a test for your cross shaft a while back. It might do you good to follow the test procedure before you open the bevel gear compartment. If the cross shaft passes and it looks like its just a brake problem, then maybe you can get away with working on it out in the field. I don't know what kind of tools you have.

If I were you, I'd check the linkage and band adjustment as suggested, test the cross shaft for bearing failure and work it. If it starts to lock up again, check the linkage to see if it's traveling completely. If you don't see any problems, then check the exterior distribution valve which sends fluid to the brake cover pistons. There may be some metal shavings in the valve which are causing it to stick. When you've exhausted those issues, its good to go on the outside, and if you think you still have a brake problem, you're going to have to follow Bob's advice and look inside.

Brake cooling started with sr. #10725. Fed from the brake cooling and lube oil press valve located in the RH steering clutch compartment. Takes two hoses part #3S8676, one for each side.

Shown in the steering clutch & transmission lube system section of the parts book (3-pages)

I would be checking that the steering clutches are disengaging fully,pull back on both steering levers to see the machine stops without using the brakes,if the clutches are not disengaging fully the brake has to stop a driven drum so heat is generated by both brake and clutch,the drum will expand and that causes brake drag,with the brake now binding the drum stays hot,when it cools down its free again,if you did not adjust the brakes recently it is not tight the go but loose unless the lining is starting to break up,check the clutches are disengaging fully and if so I would agree with Bob re the cooling lines.
AJ