Problem with 1620 HST

[ETD66SS]

In reference to this thread: http://www.tractorbynet.com/forums/parts-repairs/245977-1620-hst.html

So here it is 4 years later, and I have the same problem. The HST is leaking again. I'm in the process of splitting the tractor again

The image links in the old thread are dead, but here are the pictures from the first time around:

Disassembly in 2012: 162-Disassembly-2012: 162-Disassembly-212 - Album on Imgur

Re-assembly in 2012: 162-Reassembly-2012: 162-Reassembly-212 - Album on Imgur

I sure hope it is a just a gasket again, because I remember from the first time around, there are no HST rebuilds, only new ones for $6500...

I didn't mow with the brake on this time, but last year I started mowing in high gear, I wonder if that is just too much for the HST?

 

[ETD66SS]

Ok, so here is what happened this time to the same gasket: http://i.imgur.com/1JjirKg.jpg

Last time it was bend in just like this one, but it was torn a little bit. This time the gasket has bent in to the point it is off of the flat surface and lets oil pass by.

WTF is up with this gasket? I checked all the mating surfaces for flatness last time, and they were true, no warping.

Is this just a crap design?

 

[Clint S]

Can you try a little sealant or gasket shellac????

 

[ETD66SS]

The instructions say to only use a little bit of grease, no adhesive. But I may have to try something, because this is ridiculous to have to split the tractor every 4 years to replace this gasket.

I ordered the gaskets form partspring, as New Holland only sells the full rebuild kit.

I'd almost like to find gasket material and laser cut my own at work. There is room to make them a little wider in the areas that would help prevent the sides form sucking in. I can draw up the gasket in CAD. Only issue is the material is 0.018" think, having a hard time finding gasket material that thin.

 

[barbqranch]

McMaster Carr has gasket material 1/64 inch (.0156 inch) and 0.030 inch.

 

[ETD66SS]

McMaster Carr has gasket material 1/64 inch (.0156 inch) and 0.030 inch.

I was looking earlier on their website, but the stuff I found said it was for water. I'll take another look.

 

[ETD66SS]

So I designed a new gasket in AutoCAD and laser cut a test gasket: http://i.imgur.com/D575K3l.jpg http://i.imgur.com/02KzuGX.jpg

I don't think the material of the test gasket is what I want to use, it's 0.30" thick, whereas the original one is 0.18" thick where it was pressed together by the housing, and 0.22" think where it was not pressed together. I'm not sure if there is a possibility to mess up the operation of the HST unit if I use a gasket that is too thin or too thick.

 

[ETD66SS]

Ok so, I was wondering why the new gasket I ordered was $70. I assumed I was going to have to make my own instead of using the wimpy paper gasket. I got the new gasket in today, and it is a metal crush style gasket.

See the pic, the one on the left is the original, the one in the center is the new gasket I designed, and the one on the right is the new metal gasket, which I plan to use: http://i.imgur.com/pfOa3Nq.jpg?1

I guess the question for the pump builders out there is, I assume I use no sealant at all on the metal gasket?

 

[marc2000gt]

I wouldn't put anything on it with it having the raised lip.

 

[ETD66SS]

It's all back together and I mowed this past weekend, no leaks yet.

Hopefully I never have to do that again. If the kit I had bought 4 years ago had the metal gasket in it, I don't think I would have had to do this job twice.