8600 brakes

Ok so back to square 1 again ive had this apart a bunch of times now. New seals in the rearend. New brake discs. New master cylinder. New master cylinder seal kit. New holland brake oil. Fixed the pitting in the rearend. Pump the left brake up and just like every time before it builds hardly any pressure and looses pressure when you release the pedal. The left brake will also not release the tractor will not even freewheel down a hill. Before i push this POS off a cliff is there any other solutions. Also brake discs are not warped that i can tell. Also I separated the axle housing some pumped the pedal and it pushes the piston out just fine just not much pressure and it seems like it should suck back in.
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While I'm personally a big fan of JB Weld, I don't think I would have used it in that location. I think it certainly explains the brake drag.

As for the issue with the pressure, myself I'd isolate the master cylinder from the LH brake by swapping the brake lines above the
transmission and seeing if the problem stays with the LH side or goes to the RH side. If the problem goes to the RH side, the problem is with
your master cylinder. If the problem stays with the LH side, about the only suggestion I would have is to do some careful measurements of the
piston travel to see if some sort of a machined spacer plate could be added to your brake pack that would effectively cause your piston to
operate further inward than normal, in the better part of the machined surface.

If you lived on the west coast I'd give you a good axle housing. I can't give the thing away and haven't got around to hauling it to the
scrap yard yet.
 
Dont know how far you currently have it apart, but
next time the brake wont release, open the bleeder
on the center housing and see if that will release the
brakes. If you already have it apart, fit the piston with no seals into the bore to check for any mechanical binding, then fit the seals on
the brake piston ONE at a TIME and test fit them in
the bore for smoothness of operation. Should be light drag with seals installed. The problem
with that jb weld is that it is hard to make it stay in
shallow imperfections like that. If you got all the
rust out, then maybe... What was the reason you
took it apart, for dragging brakes or were you losing
fluid?
 
I will try to answer both comments on this post bear with me.

The bottom of the sealing surface was pitted and the first time i pulled the brakes apart the left brake was stuck all the way out and wore almost through the plate. In the last 6 years ive owned it its never had a left brake so thats 1 reason it was pulled apart but it was also loosing brake oil also.
I asked what a good fix for the pitting would be on some facebook pages and had at least 10 ppl say theyve used jb to fix this issue.

So anyways this morning i blocked off the left brake line it got solid so to be sure i hooked the left line up to the right brake and it worked like it should. So that rules out the master cyl.

Pulled the axle housing off for the 3rd time now rechecked the outer brake discs and they are for sure not warped. Pulled the piston back off and sure enough the jb weld didnt hold and the pitting was all showing again and i had sanded perfectly smooth you couldnt tell it was there. So im assuming even tho i waited 24 hrs like it said to im thinking it didnt hard enough. This time i tried cleaning it a bit better and wait an extra day for it to harden
 
As I said in my last post, try and determine how much room the piston has with regards to total travel to see if there's a way you could add
a machined spacer into the brake assembly to get the piston operating more inwards. Possibly you could even machine some material off of the
piston itself to accomplish that. Other than that, I don't have any other good ideas on this.
 
Before you try jb again, take a torch and warm up
the area where the pitting is, in order to sweat out
the oil soaked in the cast iron. Also, jb doesnt dry
all that hard, might have better luck with more
industrial style stuff like Smooth-On.
 
Since Massey 1105/35&55s used a similar brake system. We used to get an o ring every so slightly larger in diameter, so as to fit loosely in the
piston groove but still would be pushed into the cylinder cavity without damage. Worked quite well on several occasions. Maybe something to think
about!!
 
I dont understand the function of the piston springs.
The way they are pushing, that would be applying
the brake, certainly enough that you couldnt turn it
with a pipe wrench. Parts book says springs no longer
serviced, plus it says see service bulletin 3-76.
Have to call the dealer and see what thats all
about.
 
The axle will spin freely by hand until the brake builds pressure then no chance of it at all. Before i took it apart the second time i did testing and parked it on a hill and it would just sit there after the break was released. After a little bit it would slowly start to roll but never fully release.

The springs i took out the first time around. The right side didnt have them when i took it apart so I didnt put them back in

The oring for the piston is a square shape so i dont think anything else would work. But granted it feels like a tighter fit on this side then the right
 
I think if the action of the piston is stiff, that should
be addressed next. Take both seals off and see
how it fits in there. Try one seal , take it out and try
the other one. Im grasping at straws here, but it
takes very little pressure to apply the brake, and
there is only the action of the rotating members to
push the piston back , against the brake fluid.
 
Just put it back together the only progress i made was the pedal actually builds pressure without having to pump it a bunch of times. Put different piston and brake discs in it. But thats all i did different. It sticks so bad that sitting on a jack holding the right brake so it wont take off it will die the tractor down
 
What did you find wrong with the piston that made
you change it? Also why different brake disks?
Do you have any free play at the pedal, now that the brakes are there on one hit?
 
Didnt find anything wrong with them. I have 3 parts tractors and just decided to put different parts to see if it would make a difference. The pedal goes down about half way on both sides before its pretty firm and thats how the right has always been. Left side has never worked since i owned the tractor
 
One thing I dont understand is the statement of (a
new master cylinder and seal kit). Did you have the
master cylinder apart ? Are we absolutely sure the
system is not retaining pressure? When you
changed the piston, did the action feel any
smoother than the previous one? You had said it
was noticeably stiffer.
 
Meaning the pedal is noticeably stiffer. And yes new master cylinder for a c10 truck which is the same as these tractors and i put a new tractor seal kit. But no there not the problem cause i was having the same issues with the old master cyl and old seals. It cant be the master cyl retaining pressure because when i open the bleeder i still cant spin the axle with a pipe wrench and 5 ft pipe
 
Can you get access to a little hand held vacuum
pump? I would like to see if you can apply enough
vacuum to pull the piston back in . Not that this
would solve anything, but I would like to see how
bad the thing is stuck. In any case, youre going to
have to take it apart again. I wonder if the JB failed
again, or the rubber is actually sticking to the JB, to
where you will have to switch to a different pit filler,
duraglas maybe? I refuse to believe there is no way
to fix this without replacing the center housing.
 
Does the piston move smoothly in the bore without the seals on it? In other words, have you verified that there is no issue with the
clearance between the piston and the bore?

If that's OK, I would think you simply need to smooth down your repaired surfaces some more.
 
Can you get access to a little hand held vacuum
pump? I would like to see if you can apply enough
vacuum to pull the piston back in . Not that this
would solve anything, but I would like to see how
bad the thing is stuck. In any case, youre going to
have to take it apart again. I wonder if the JB failed
again, or the rubber is actually sticking to the JB, to
where you will have to switch to a different pit filler,
duraglas maybe? I refuse to believe there is no way
to fix this without replacing the center housing.
 
I can pick one of those vacume pumps up at harbor freight I believe next time i go. Im thinking the jb weld smeared off again but who knows. Ill pull it back apart tomorrow. And i tried 2 different pistons without the seals on if it goes in perfectly straight it will slide in cant be cockeyed what so ever. Just to give you guys an idea how much pressure it has on the brakes 8th gear on the jack about kills the tractor it will die it dpwn to about 4-500 rpm
 
If the piston is that sensitive to misalignment, Im
wondering if there is something under the ring gear,
like a burr or some foreign material from previous
disassembly, so that it is not perfectly
perpendicular to the axle, so when the brake parts
stack up tight , it cocks the piston in the bore and
causes it to jamb. Maybe you should forget the
vacuum pump idea , it might be better to see the
current position of the piston when you take it apart.
If its nearly stalling the tractor, it probably wont
retract anyway.
 

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