3PH Drooping

Work Horse

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B7200 HST 4x4
Jan 21, 2020
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I did NOT intend to imply that your problem was anything similar to the thread I linked to.

I just wanted you to get a good understanding of what the control position valve and feedback rod were doing.

Sorry if I gave you the incorrect impression.
All is good, I ended up reading through the entire thread just out of interest. So - thank you!

I just ordered $30 in misc gaskets, O-rings, and seals, should have them at some point next week. The seals for the cylinder were cheap so I went ahead and ordered those to... though I plan to start with Dan's suggestion and take it from there.
 

Work Horse

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B7200 HST 4x4
Jan 21, 2020
152
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Sooooo.... not the greatest of news.

The cylinder and the piston are scored. That being said I was surprised the piston head popped out while moving the 3PH lever back and forth by hand... it appears to just he friction kept

Anyways, I decided to replace all of those seals - they were cheap enough.

I doubt that will "fix" the issue, but maybe it will help. I think the only other option would be to replace the piston and the cylinder, not sure if that's really worth it at this point. Unless they can be reworked somehow?

I haven't had a chance to officially test it yet... but I'll try it out tomorrow.
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D2Cat

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The scoring on the piston and cylinder will cause the "O" ring to wear a bit faster, but it should still do what it needs to do and may last for years! I'd consider taking a 1000 grit emery cloth and knock off outstanding ridges to help the seal last longer.
 
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Work Horse

Member

Equipment
B7200 HST 4x4
Jan 21, 2020
152
6
18
IPSWICH
The scoring on the piston and cylinder will cause the "O" ring to wear a bit faster, but it should still do what it needs to do and may last for years! I'd consider taking a 1000 grit emery cloth and knock off outstanding ridges to help the seal last longer.
Thats a good idea, I'll give that a shot later this morning!

I already noticed a much more positive engagement pushing the piston back in by hand yesterday... makes sense seeing as the old O ring had completely flatened out.

I hope you're right and this is all I need. Thanks again
 
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Work Horse

Member

Equipment
B7200 HST 4x4
Jan 21, 2020
152
6
18
IPSWICH
So I started with a scotch brite, and ended up using a bristle brush on a right angle grinder/sander to clean up the deep grooves on the cylinder and piston. It didn't "remove" them but it did help smooth them out.

I've now had the 3PH raised up for hours without it drooping down at all, the lever action is a lot more positive/responsive, and I lifted up a trailer (via a ball/hitch attachment), that I've never been able to lift and move around before.

I'm pleasantly surprised at how easy and cheap the issue was to fix - for once..... thankn you all (eapecially Dan) for the patience and guidance along the way.

For anyone with a similar issue on a similar machine: All that us needed us to remove the seat, cross brace between the two rear fenders, and the four bolts securing the top of the piston/cylinder.
 

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