Hydraulic Welch plug popped

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55cubster
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Joined: Thu Jun 15, 2023 8:18 pm
Zip Code: 15658

Hydraulic Welch plug popped

Postby 55cubster » Thu Jun 15, 2023 8:34 pm

Hello Everbody. New to forum but have had my "55 cub for approximately 30 years. Main chore of mowing. Had a hydraulic control valve leak that I addressed when putting in new clutch. Decided to do rebuild kit since the cub is older than me even though lift appeared ok. Following rebuild the engine sounded a little labored at operational speed and a little lacking in power. Then "pop," Welch plug blew. What did I do wrong with rebuild or can you direct me.to the cause? If it ain't broke...don't TRY to fix it. Thanks in advance for any advice!

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Glen
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Tractors Owned: 1956 Farmall Cub with Fast Hitch, F-11 plow, Disc, Cultivator, Cub-22 mower
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Re: Hydraulic Welch plug popped

Postby Glen » Thu Jun 15, 2023 10:55 pm

Hi,
The 1955 Cub operator's manual says to fill the Touch Control system the last time after removing the air, with the arms in the rear or down position. The fluid level rises in the unit as the arms go to the rear.
If you filled it with the arms ahead, it is overfilled.
When you move the arms to the down position with too much fluid in it, it might make enough pressure to blow out the plug on top of the block, that's a guess.
Last edited by Glen on Fri Jun 16, 2023 1:27 am, edited 1 time in total.

Jim Becker
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Re: Hydraulic Welch plug popped

Postby Jim Becker » Thu Jun 15, 2023 11:44 pm

Yes, what Glen said could be the story or a piece of it. However, the sounding labored and lacking power leads me to think the stops that limit movement of the control lever were not correctly adjusted. If so, the control may have been pushed beyond the proper end of movement. This could leave the system trying to push the rockshaft too far and leaving the system at high pressure with fluid flow going through the pressure control valve. This will quickly overheat the system. Higher temperature causees higher pressure in the reservoir.

55cubster
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Re: Hydraulic Welch plug popped

Postby 55cubster » Fri Jun 16, 2023 6:23 am

Thanks for your input. The fluid was filled as per manual. The lever was " midrange" and no adjustments were made to stops / linkage of rod. Any chance one of the valves could be stuck and if so which one?

Jim Becker
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Re: Hydraulic Welch plug popped

Postby Jim Becker » Fri Jun 16, 2023 11:01 pm

As long as the engine isn't laboring from a hydraulic load, I'd put in a new plug and forget about it. If it happens again, I would start digging deeper.

55cubster
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Re: Hydraulic Welch plug popped

Postby 55cubster » Sat Jun 17, 2023 8:15 pm

Thank-you Jim for your support. Will get back to it hopefully next week. Been studying the TC manual. I have 2 questions: 1. Do you think the o-rings would be fried and need replaced? And 2. The two openings on the Control valve - should they be oriented to the outside of the unit (drivers left)? That's how I placed it. Thanks again for your help. Dave.

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Re: Hydraulic Welch plug popped

Postby Jim Becker » Sun Jun 18, 2023 8:26 pm

I wouldn't worry about o-rings as long as they are still doing the intended job. That would be no external leaks, the lift not settling down when it is parked, and fluid isn't leaking from the pump into the engine.

I don't have the answer to the second queston. Maybe someone that has had one apart recently can answer.

55cubster
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Re: Hydraulic Welch plug popped

Postby 55cubster » Mon Jun 19, 2023 9:26 pm

Thanks. I'l l keep you posted here as to how it goes when I get.back to it in the next.week or so. Dave


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