Help with M6800 Brakes

[camobob]

Hi, new member here, first post.
I recently retired and bought a used M6800. The tractor seems okay but the brakes are weak and the linkages are fully adjusted. Service manual shows wet discs inside the rear of the tractor which means tires come off and cases are split. It seems doable to me. Just handling the tires and cases is my biggest worry so far. Being new to tractors I'm hoping that someone with experience can tell me what I'm really getting into and maybe offer a little advice.
Thanks!

 

[TheOldHokie]

Hi, new member here, first post.
I recently retired and bought a used M6800. The tractor seems okay but the brakes are weak and the linkages are fully adjusted. Service manual shows wet discs inside the rear of the tractor which means tires come off and cases are split. It seems doable to me. Just handling the tires and cases is my biggest worry so far. Being new to tractors I'm hoping that someone with experience can tell me what I'm really getting into and maybe offer a little advice.
Thanks!

If you have good mechanical skills and a good place to work (concrete floor) it should not be a big deal but if not perhaps a bit ambitious as an outdoor learning experience.

If you do take it on you are into bigger and heavier components - stuff I can't man handle around. That means things like larger wrenches, bigger floor jacks, a shop crane, wheel dolly, etc. Over the course of 30+ years I have acquired a pretty good collection with most purchased as the need arose. I justify the cost by the money saved not paying someone to do it. At age 70 that justification is getting harder to find but I imagine the service quote from a dealer for this job would clear that bar and then some.

Dan

 

[camobob]

Thanks Dan,
I'm pretty good mechanically. At 62 I can still handle reasonable stuff but need to think a lot more than I used to. I have a good workspace but am slightly concerned about weight since the tractor is my forklift. I was hoping to use my mini excavator to help out with the tires and maybe the cases.
Any thoughts on that/ What I really don't know is the particulars of the tractor. What else do I need to replace while I'm in there? seals, gaskets, maybe gears that need inspected? are there any adjustments that need to be done (gear lash), etc....
Is it really just drain the oil, take it apart, replace the plates and reverse?

 

[Russell King]

Do you know if the tires are filled with some liquid?

If so the tires will be very heavy. They will need to be kept vertical when removed and tied up during the time that they are off the tractor unless you have a method to lift them. You should have someone help you with removing them and probably someone to be the safety watchdog in case something happens and the wheel falls onto someone.

It is doable but some risks involved. Barely jack the tractor up so the tire is still on the ground when removing it. Maybe you will only have bolts that attach it so it can just be rolled away from the tractor carefully. If you’re really concerned you may be able to find a tire repair truck with a crane to remove the tires and replace them when the brake job is done for a reasonable price?

 

[TheOldHokie]

Thanks Dan,
I'm pretty good mechanically. At 62 I can still handle reasonable stuff but need to think a lot more than I used to. I have a good workspace but am slightly concerned about weight since the tractor is my forklift. I was hoping to use my mini excavator to help out with the tires and maybe the cases.
Any thoughts on that/ What I really don't know is the particulars of the tractor. What else do I need to replace while I'm in there? seals, gaskets, maybe gears that need inspected? are there any adjustments that need to be done (gear lash), etc....
Is it really just drain the oil, take it apart, replace the plates and reverse?

The mini-ex should make a fine shop crane if you can get in position. Loaded tires are hard to get on the hub with a crane but if you have a helper and floor jack they are not too bad. By yourself they will give you a good workout.

I cant speak to the particulars of that repair but the workshop manual should have all of the info you need. You can probably download a copy for free if you dont have one. They are essential documentation.

Good luck

Dan

 

[GeoHorn]

Get a WSM for your model tractor BEFORE you attempt this. (WSM= Work Shop Manual)

If you let a liquid-filled tire fall on you…or if you try to prevent it from falling on you…. you are going to be SERIOUSLY hurt. Use that excavator and chains to put thru the upper spokes to support/lift/move those filled tires. Don’t even THINK about doing this alone.

 

[camobob]

I have the manual, tools etc. I know well how to work carefully and certainly appreciate the concern.
Do you have a guess on the weight of a filled tire on cast rims? The manual doesn't list that and will make a big difference in how I support the tire.

 

[TheOldHokie]

I have the manual, tools etc. I know well how to work carefully and certainly appreciate the concern.
Do you have a guess on the weight of a filled tire on cast rims? The manual doesn't list that and will make a big difference in how I support the tire.

Depends on the fluid. Google says 16.9-30 tires so figure 800# or so.
Rimgard would add 800 by itself.

Dan

 

[camobob]

I didn't realize the fill added that much. So depending on the wheel weights and fill I'm going to figure 1200 to 1400 lbs per tire.

 

[Tx Jim]

I didn't realize the fill added that much. So depending on the wheel weights and fill I'm going to figure 1200 to 1400 lbs per tire.

I think you're correct liquid filled rear tire with cast centers will weigh a least 1400#s each. My M7040 operators manual states rear cast centers @ 350#s each. If using extreme care 2 people can remove/roll loaded rear tires to be able to R&R rear axle & brake disk. BTDT several times in the past.

 

[camobob]

Yes sir, two people and extreme caution it is. may also try to set up the excavator as a safety somehow if that's not overly complicated. My main question is what else to look for while I'm in there.
Do I need to replace any seals or other parts?