Farm Equipment - Hydralics question

Hydralics question

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Category: Allis Chalmers
Forum Name: Farm Equipment
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=159890
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Topic: Hydralics question

Posted By: IBWD MIke
Subject: Hydralics question
Date Posted: 11 Apr 2019 at 10:17am

I had an 'incident' over the weekend that got me around to posting this topic. Was going to do a little brush-hogging with the D-17. When I raised the mower, it blew a pipe nipple, (schedule 40, black iron) dumped the pressure and down comes the mower. I see this kind of plumbing on LOTS of tractors and know it's not right. At work when we run high pressure air, about 280 PSI, we use schedule 80 pipe. Lots of loaders plumed with schedule 40 black iron or galvanized pipe fittings. Is everyone just luck they don't blow at any given time?

So, for a 3500 PSI system, what are the correct fittings? I have made nipples out of some scrap schedule 160 pipe, that is what I used to fix the problem.

This tractor came from an auction and was a plumbers nightmare. Have been working on fixing the leaks and ugliness for a while now. Knew this needed to be addressed, this got me off the pot.

Replies:

Posted By: Jim.ME
Date Posted: 11 Apr 2019 at 1:27pm

160 should hold it. Seeing hardware store plumbing in hydraulic systems is scary and just lucky if it doesn't blow in my opinion. I use hydraulic adapter fittings and 2 or 4 wire hydraulic hoses for the pressure side of hydraulic systems. For return or suction I might use Schedule 40, prefer schedule 80 if available, black iron pipe, depending on the system. If I needed a long hard line I would go to an industrial tubing supplier and get rated tubing and fittings.

Another problem with using off the shelf pipe and fittings is cleanliness. There can be flaking and scale inside pipe unless cleaned and treated properly for the intended service. Galvanized is a definite no, due to possible internal peeling.

This is a good thing to think about. Blowing apart is one thing; getting an injection of oil through the skin from a pinhole leak can lead to infection, loss of a body part(s) or death.

Posted By: Tbone95
Date Posted: 11 Apr 2019 at 1:29pm

I don't compromise, I buy hydraulic rated fittings and tubing. But.....yeah, Sch 160 should hold it for typical tractor line diameters.

Posted By: DSeries4
Date Posted: 11 Apr 2019 at 9:01pm

For me, having a good hydraulic shop is almost as important as having a good local fabrication shop. Dealing with tractors of this age, both of these shops get a lot of business from me! But, I know that everything will be fixed right and will be safe.

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'49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '63 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080

Posted By: IBWD MIke
Date Posted: 12 Apr 2019 at 9:32am

Thanks guys, will look into the correct fittings. I've seen this on lots of farm tractors, surprising you don't hear of more problems.