Missing 402 brake valve spring (RESOLVED and close)

[scpike]

I'm disassembling my 4020 (early model) brake valve in preparation for a rebuild. It appears I am missing a spring in each brake piston assembly (see pics).

Was this a change, a previous goof-up, or ???

Thanks for any help.

Stu

****UPDATE****

Turned out the JD distribution center in Denver had the springs. I ran in and picked them up.

They are much larger than I expected, and are obviously a critical part of the valve. I'm a bit amazed that the brakes worked before (for about 10 years!)

Anyway, here's a picture. Thanks for the help.

Stu

 

[JIM MN]

Why are you rebuilding the brake valve? Was it not working? Was it working without the springs? Do you need the springs if all was working just fine now?

 

[scpike]

I was having hydraulic issues (mostly steering related), and I disassembled the tractor (without splitting it) at the end of 2019. Before that, the brakes were "OK" but not great. And I need to say here that I am not a farmer, and this is the only tractor I have ever owned. We had about 6 pair of cattle and several horses when the kids were still home, and I used the tractor to support those animals. I do have a good understanding of (older) automotive technology.

I rebuilt the hydraulic pump and the steering motor, did some painting prep and the project stalled. Now I am getting it back together, and the boots on the brake valve were in bad shape, so I ordered new ones. In pulling it apart I found more problems, mostly significant corrosion causing limited piston travel (especially for the right brake) under the boots.

So that's it. To answer your question about functionality, I see no reason why the valve won't work like it did before if I re-assemble it without the springs - but they were in the design for a reason, and since I have the darn thing apart, now is the time to correct it. The big issue for me is I want to finish it up; but getting my hands on these springs will create another 2-5 day delay.

Are there common substitutes for these springs? I suspect they are something guys don't normally deal with or order.

 

[wore out]

I was having hydraulic issues (mostly steering related), and I disassembled the tractor (without splitting it) at the end of 2019. Before that, the brakes were "OK" but not great. And I need to say here that I am not a farmer, and this is the only tractor I have ever owned. We had about 6 pair of cattle and several horses when the kids were still home, and I used the tractor to support those animals. I do have a good understanding of (older) automotive technology.

I rebuilt the hydraulic pump and the steering motor, did some painting prep and the project stalled. Now I am getting it back together, and the boots on the brake valve were in bad shape, so I ordered new ones. In pulling it apart I found more problems, mostly significant corrosion causing limited piston travel (especially for the right brake) under the boots.

So that's it. To answer your question about functionality, I see no reason why the valve won't work like it did before if I re-assemble it without the springs - but they were in the design for a reason, and since I have the darn thing apart, now is the time to correct it. The big issue for me is I want to finish it up; but getting my hands on these springs will create another 2-5 day delay.

Are there common substitutes for these springs? I suspect they are something guys don't normally deal with or order.

Are you SURE the little springs aren't hiding inside parts Key #5?

I don't think the parts drawing is all to scale, I don't think those little springs are as large as they appear next to the parts drawn next to them.

 

[scpike]

Hi wore out

It's the right one.

Here's the picture of one of the springs and the package it came in with the JD part number.

AND - I actually did have the originals. I had placed them (out of the way) in the wrong area on my bench during disassembly and didn't remember that. That solves why the brakes worked before - the valve had been assembled properly ;-(

Old guy stuff.