484 Brake Loss After Sitting

[ford4wd08]

Brakes are still bleeding down. Seems to be faster than before.

Is there any way to test that it is not the master cylinders vs the seals in the brake pistons?

They both bleed down fast at basically the same rate, I'm really starting to wonder if it is the master cylinders since I can bleed them and get a very stiff pedal, but it is gone after one shutdown and some setting, even the next day.

I wouldn't think brake pistons would both bleed down like that, but I may be grasping at straws.

 

[RedMVa]

Brakes are still bleeding down. Seems to be faster than before.

Is there any way to test that it is not the master cylinders vs the seals in the brake pistons?

They both bleed down fast at basically the same rate, I'm really starting to wonder if it is the master cylinders since I can bleed them and get a very stiff pedal, but it is gone after one shutdown and some setting, even the next day.

I wouldn't think brake pistons would both bleed down like that, but I may be grasping at straws.

If the master cylinders are not leaking externally ( if you can’t see any leaks) then they’re not likely the problem. Orings need replaced, and wouldn’t hurt to do the master cylinders too while you’re doing it

 

[MARK ROBKE]

Brakes are still bleeding down. Seems to be faster than before.

Is there any way to test that it is not the master cylinders vs the seals in the brake pistons?

They both bleed down fast at basically the same rate, I'm really starting to wonder if it is the master cylinders since I can bleed them and get a very stiff pedal, but it is gone after one shutdown and some setting, even the next day.

I wouldn't think brake pistons would both bleed down like that, but I may be grasping at straws.

I worked for an old former IH dealer after I retired for a couple of years. He had a jig made up to pressurize the brake pistons in the axle. I think we used air. If they held, then of course it was the master cylinders. I did a bunch brake piston seal jobs while I was there and only replaced maybe 2-3 master cylinders. There are 2 grades of piston seals - the red is better as I recall. The piston seals were almost always the cause, yet they seldom looked bad, just a little flat. Mark.

 

[Fritz Maurer]

If there are rebuild kits available, or even complete units, would it not be worth the effort to try the easy thing first?

This is assuming that there are no external leaks.

Faulty rubber hoses don't necessarily have to be dripping to cause trouble. All they have to do is let a little air into the system.

If this tractor has any rubber in the system, and the outer sheath is cracking, I'd change those first.

 

[RedMVa]

If there are rebuild kits available, or even complete units, would it not be worth the effort to try the easy thing first?

This is assuming that there are no external leaks.

Faulty rubber hoses don't necessarily have to be dripping to cause trouble. All they have to do is let a little air into the system.

If this tractor has any rubber in the system, and the outer sheath is cracking, I'd change those first.

Yes there’s hose and it’s under slight pressure, 2 gpm I believe, so it will show an external leak. I just did a 585 (my own) and it was exactly like this one , did the orings and rebuilt both masters while I had it apart. I’ve done quite a few over the years, orings are going to fix it but the whole system should be gone over.

 

[ford4wd08]

As suspected it was the O-rings.

Luckily, I had a buddy who knew a mechanic that would do the work for me.

I usually try to do all my repairs myself, but pulling the final drives was more than I could do the way my shop is currently equipped.

He turned it around in less than a week. Brakes have held ever since.