Massey 2660HD rear brake issue

[JWR]

Maybe back off 1 full turn. The brake expander should slide back into place.

Good thing to try. I have a MF 2660HD myself which I bought new in 2011. Because I operate often on steep ground, brakes can be a major issue. I can get very wordy and talk 2660 brakes longer than you want to hear, but I'll try to narrow more to your situation.

1. I do not think that the leak you noticed is a factor.
2. Your tractor has an equalization linkage between right and left sides. Founded on some lawyer's idea that we really don't deserve wheel brakes that work. Be interesting to see if yours has had that feature disabled (many owners have had that done and some dealers were routinely doing it.) Potentially someone tried to do that and dorked up your brakes? Probably not, but just thought you should be aware.
3. My brakes squeak like crazy on one side but not the other and do it only under stronger braking. Your story (orig post guy) makes me wonder if mine will go beyond squeak and start sticking.
4. Is yours a 4 disc or 5 disc system ? Four disc systems were sold nationwide to pinch mfr pennys hoping not very many would complain. The 4 disc system will not hold you on a 40% slope without creeping, even with over 150 lbs on the brake pedals. Mine (and others) were fixed by adding a 5th disc to each side and now mine are "good." [You can tell by the number of notches on each side of your bugles.] This too may be unrelated to your sticking problem.
5. I assume you know that working on those brakes is a major and costly procedure involving significant disassembly of the rear, taking off a lot of sheet metal, etc. In your case even worse being a cab model. Mine is ROPS. IF THE REAR HAS TO BE TAKEN APART be very sure that the person doing it does not wring off the threads on the bolts reattaching the bugels and that he does get them good and tight. Mine was reassembled poorly with some wrung off and some left loose. Hideous in part because once it is reassembled you cannot get to half the bolts to tighten or replace them (!!) Stand over them if you are not doing the work yourself.

 

[sawtooth]

Good thing to try. I have a MF 2660HD myself which I bought new in 2011. Because I operate often on steep ground, brakes can be a major issue. I can get very wordy and talk 2660 brakes longer than you want to hear, but I'll try to narrow more to your situation.

1. I do not think that the leak you noticed is a factor.
2. Your tractor has an equalization linkage between right and left sides. Founded on some lawyer's idea that we really don't deserve wheel brakes that work. Be interesting to see if yours has had that feature disabled (many owners have had that done and some dealers were routinely doing it.) Potentially someone tried to do that and dorked up your brakes? Probably not, but just thought you should be aware.
3. My brakes squeak like crazy on one side but not the other and do it only under stronger braking. Your story (orig post guy) makes me wonder if mine will go beyond squeak and start sticking.
4. Is yours a 4 disc or 5 disc system ? Four disc systems were sold nationwide to pinch mfr pennys hoping not very many would complain. The 4 disc system will not hold you on a 40% slope without creeping, even with over 150 lbs on the brake pedals. Mine (and others) were fixed by adding a 5th disc to each side and now mine are "good." [You can tell by the number of notches on each side of your bugles.] This too may be unrelated to your sticking problem.
5. I assume you know that working on those brakes is a major and costly procedure involving significant disassembly of the rear, taking off a lot of sheet metal, etc. In your case even worse being a cab model. Mine is ROPS. IF THE REAR HAS TO BE TAKEN APART be very sure that the person doing it does not wring off the threads on the bolts reattaching the bugels and that he does get them good and tight. Mine was reassembled poorly with some wrung off and some left loose. Hideous in part because once it is reassembled you cannot get to half the bolts to tighten or replace them (!!) Stand over them if you are not doing the work yourself.

Hello JWR,

We spoke last summer about this tractor and you helped me look at several things which I still appreciate. The tractor has been improved to the 5 disk setup and stops great just need to get the right brake to fully released which it does sometimes. Remind me though what is the equalization linkage again?

Here is the tractor with a recently found Athens 65 disk. It weights 1700lbs and lifts it without issues. Can’t wait to stick both of these in the dirt but need to address the brakes first.

 

[JWR]

Hello JWR,

We spoke last summer about this tractor and you helped me look at several things which I still appreciate. The tractor has been improved to the 5 disk setup and stops great just need to get the right brake to fully released which it does sometimes. Remind me though what is the equalization linkage again?

Here is the tractor with a recently found Athens 65 disk. It weights 1700lbs and lifts it without issues. Can稚 wait to stick both of these in the dirt but need to address the brakes first. View attachment 639056

Lookin good. That is a beauty. New and well kept looking. The equalization is in the brake fluid side of the braking system up under the cosole. You have 2 master cylinders, one for the left and one for the right. The equalization line (and maybe check valves, I'm not real sure) run between the two sides. The intention is to prevent people from jamming on a left or right brake without catching the other brake pedal while running at higher speeds on pavement, during highway transport, etc. I have not studied it enough to know exactly how that works. The effect is to defeat wheel brakes to one extent or another and my dealer advised defeating it (after asking me if I wanted normal wheel brakes.)

 

[sawtooth]

Lookin good. That is a beauty. New and well kept looking. The equalization is in the brake fluid side of the braking system up under the cosole. You have 2 master cylinders, one for the left and one for the right. The equalization line (and maybe check valves, I'm not real sure) run between the two sides. The intention is to prevent people from jamming on a left or right brake without catching the other brake pedal while running at higher speeds on pavement, during highway transport, etc. I have not studied it enough to know exactly how that works. The effect is to defeat wheel brakes to one extent or another and my dealer advised defeating it (after asking me if I wanted normal wheel brakes.)

Ok understood. I will check into this with my dealer. Definitely something I would like to defeat. Thank you

 

[sawtooth]

Maybe check if the spring is still in place too. Number 50 on the diagram.View attachment 638977View attachment 638978

This is something I will address this weekend. Great info and much appreciated.

 

[sawtooth]

Turned out to be air in the system. I bleed the lines but then a couple hours later the problem returned on the right brake. So looks like will need repaired which appears to be a costly ordeal. The rest of the tractor is awesome though so guess it will be worth it but I suspect a 2000-2500 repair cost.

 

[JWR]

If bleeding the lines caused the problem to go away for a while, then i don't see how the problem is internal to the rear axle nor why it would require that large an expense to repair. The master cylinder side of things is up under your console along with much of the plumbing. There is an hydraulic cylinder pair inside the chassis but I think there is an access panel on the right side of the chassis to that part of the brake system. Inside the rear axle bugle housings you have the discs and rings that serve as pads. Only if those were haywire would you need to tear down the rear.

If bleeding the lines made a difference for a couple hours of operating time I'd do one heck of a lot of investigating before digging inside. Had yours been altered to get rid of the left-right equalization? If not I'd have that done first.

p.s.: come to think of it you said air in the lines? Air in the lines would cause soft pedals or LACK of brakes, not sticking/jamming. MAYBE, if you have not had the equalization removed, the equalization might be doing the jamming as a reaction to loss of brake line pressure in one of the two sides. (??)

 

[sawtooth]

Hello JWR,

No I have not done the defeat option yet. Can you tell me how to do that again please? It is strange as once air starts getting in the system the right pedal travel is greatly reduced then the brake begins to stay slightly engaged where the brake won’t fully release. Once I bleed the brakes though the pedal travels about 1-2” then I can feel brake starting to engage. At this point the left and right sides feel about the same.

 

[JWR]

With the air entry you describe, I wonder how the air is getting there. Possibly a break or damage to one of the brake lines (or somehow a loss of fluid in one or the other master cylinder reservoirs.) Possibly the brake lines have been apart in the past and just not sufficiently bled. You probably know that sometimes bleeding brakes requires several trys in order to get rid of all the bubbles.

I wonder if defeating the equalization feature had already been done? Probably NOT. I lean toward believing that is a key part of your problem. I am not knowledgeable enough to explain in detail how to do it. My dealer performed the disconnect of the "equalization" system between the left and right. At the time as I recall the dealer said there was a brake fluid line between the two circuits. left and right, that was removed. I do not know if there were check valves too or other important details as to how it was done. If a dealer capable, familiar and willing to do it is not handy you should be able to speak with your regional AGCO service representative. I'm sure they have access to documentation on it and should be helpful. I would connect you with my dealer who made the change on my 2660 and at least one other 2660 that I know of in 2011, BUT they went out of business in 2015.

Sorry I can't help more. Do you have a shop service manual ?

 

[sawtooth]

Ok no worries and do appreciate what your able to assist with. Also I don’t have a shop manual but plan to order one today. As I find out more I will keep you posted. I’m going to bleed it more this weekend so see if things improved first. Maybe I will get lucky. Thanks.