Replacing oil petcocks

Farmall H, HV & Super H, 300 & 350, 1939-1958
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Art Cube
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Replacing oil petcocks

Postby Art Cube » Thu Aug 01, 2019 5:05 am

Hi,

I got as 1940 H a while back and when I changed the oil the spinners on the petcocks just turned off instead of opening. I see they are available to purchase so that's not an issue.

I took a vise grip to try and turn them out but either it's not supposed to be easy or they look almost welded in. I don't want to break them apart and have a mess as the tractor runs fine and I can still open the top one using a vise grip.

Any advice on changing these out would be great.

Thanks,
Rob

Jim Becker
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Re: Replacing oil petcocks

Postby Jim Becker » Thu Aug 01, 2019 11:51 am

They screw in, pipe thread. The problem installing them is getting the opening pointing down. They may have been overtightened to accomplish that.

Art Cube
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Re: Replacing oil petcocks

Postby Art Cube » Thu Aug 01, 2019 2:49 pm

2019-08-01 08.49.38.jpg
Here's a photo. I guess more effort is all that's required.

Scrivet
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Re: Replacing oil petcocks

Postby Scrivet » Thu Aug 01, 2019 7:45 pm

Looks typical. Someone has over tightened them to shut off, or more likely, tried turning the wrong way to open them (clockwise to open) one to many times and snapped off the "handles". If you're going to replace them put a pipe wrench on them and unscrew the whole thing (counter-clockwise) from the oil pan. When you get the new ones installed, the valve itself doesn't need seated much more than finger tight.

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Re: Replacing oil petcocks

Postby Art Cube » Fri Aug 02, 2019 5:12 am

Thanks, I hadn't thought of using a pipe wrench.

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Rick Spivey
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Re: Replacing oil petcocks

Postby Rick Spivey » Fri Aug 02, 2019 5:26 am

As Scrivet said, and I just want to highlight, the petcock portion is reverse threaded, so clockwise to open, ccw to close. No "rightie tightie" on these!
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Jim Becker
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Re: Replacing oil petcocks

Postby Jim Becker » Fri Aug 02, 2019 10:10 am

Rick Spivey wrote:As Scrivet said, and I just want to highlight, the petcock portion is reverse threaded, so clockwise to open, ccw to close. No "rightie tightie" on these!

NO NO NO.

That is how the handles get twisted off -- usually somebody turning CCW to try to close it. They are left handed threads but also a back seating valve. You turn it CCW to open and CW to close.

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Re: Replacing oil petcocks

Postby John *.?-!.* cub owner » Fri Aug 02, 2019 7:51 pm

Jim beat me to it.
If you are not part of the solution,
you are part of the problem!!!

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Rick Spivey
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Re: Replacing oil petcocks

Postby Rick Spivey » Sat Aug 03, 2019 6:16 am

Oops, Sorry Guys, Jim is correct. I remembered that something was "odd" about these compared to a bolt. When I'm turning it CW to close, it is actually backing out of the housing due to the left hand threads and back seating valve. Sorry for my confusion! I had to walk out to the H this morning to get it straight in my head.
Rick Spivey
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'48 Cub with FH ("Gunny Cub") 38xxx
'57 Lambretta (a slow work in progress)
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