Hydraulic cylinder return line breakage

U4ick

Advanced Member
Joined
Mar 14, 2017
Messages
51
Location
Dallas Tx.
Hello,

Just returned home and the top would not raise, found a tear in the orange return line where it turns to go to the cylinder, obviously snagged on something, no fluid in tank. I need about 3 ft. of that orange line, a barbed nipple to connect to the line before the tear and the plastic fitting that connects the line to the cylinder.

Will plumbing fittings work or do I need something rated for more pressure, any ideas on where to get some of that orange line? Any idea of how much that hydro tank holds?
2704t Thanks
 
I think you can use practically any kind of tubing, such as the clear plastic tubing you can find in an Ace Hardware store. They may be able to help you with fittings too. As far as I know, this line endures no pressure, it's essentially just a drain. Treeclimber would be able to correct me if I'm wrong, but he's not able to access the internet much at the moment.

I don't know how much Dexron II, III, IV or V fluid the system uses, but I would guess, just looking at it, that two quarts should just about do the job. Don't use Dexron VI (6)! It's not compatible.

- Jack
 
U4ick, That orange line must have been a replacement. As Jack stated that line is just a static line, meaning if you have an internal leak in the cylinder, that line will return fluid to the reservoir. I truly don't understand why the reservoir would be drained. I'm almost certain a small weak check valve prevents fluid from the reservoir entering the CLEAR tubing.
People at Lowes must think I'm nuts. I come here to purchase, but also to access the forum. I really miss chatting with everyone. I'll be back in full status in early Oct.
Tree
 
Tree, Just wrote out a long reply detailing everything that happened and when I went to submit it it said that I was not logged in, but I absolutely was, and I was not able to recover it. Anyway, the orange return line turned out to be 300psi rated 3/8" air compressor hose, if nobody else has that then I guess the PO replaced it with that. When raising the top it would go up part way then sink back down and then when I touched the up button it sounded like a starter motor on a test bench and no movement.I guess I was inadvertently pumping all the fluid onto the ground. Anyway, after repairing the line and refilling with Dexron III, I'm back in business, going up and down. Thanks!
 
U4ic, Ran up here to Lowes to respond. Now I understand a bit better. That wasn't the static line. The PO must have replaced the PRESSURE line with a 300psi flex line. Trouble is, the reason Hi Lo used a steel line is the the operating pressure is about 1750 psi. When rebuilt, the cylinders are pressure tested to 1 and 1/2 to operating pressure. That test pressure is 2600 psi. I truly hope your newly replaced line will handle that.
Tree
 
U4ick - I'm sorry I misled you! It sounded to me that you were describing the return line which, as Tree said, carries no pressure. If you've replaced your pressure line with something other than a line rated to the higher pressure that Tree gave you, you should probably replace it again. However, I'm happy you've got it working, and learned something about the system in the process.

- Jack
 
Whoa! Settle down!

The high pressure metal line is still intact, the orange air hose was used as the drain line and that is what I repaired with hose and plumbing fittings from Ace. I guess it was spraying out of the drain line when it was coming down?

Anyway, Thank You for your concern!
 
Whew! OK, thanks for clarifying! Sounds like you are in good shape then. And, I think your diagnosis that it was spraying out when the top was coming down is correct.

One of the reasons I participate in this post is to learn and to offer help whenever I can. That same ethic motivates most all of our members. My one fear, though, is that I will give incorrect advice, which, if followed, would cause harm. For this reason, I never respond if I don't feel qualified to give an answer to a question. But there are always "shades of gray", where I toss in a bit of guesswork.

- Jack
 
Just a note of interest on these lines. My 1998 Classic is parked in a covered carport about 100 feet from the Gulf in the Keys. Over the years the copper pressure line developed pin holes and had to be replaced. Instead of copper I used a custom fitted flexible hydraulic lines non metal shield. The metal line was brought to the shop as well as the fitting which can rotate to the cylinder. It would have been very difficult to fit a copper line with the exact bends. The hose was made a little larger so that I would have wiggle room. While underneath the shaft was inspected and lubricated which had not been done since it came out of the factor.
 
Quick question, what king of replacement hose did you get? Does it have to be a hard plastic or the soft flexible hose? I need to replace mine too and my husband says it has to be a hard plastic hose and having a hard time finding a clear one. Is it about 12 feet and 3/8 inches or what are the measurements if you can remember? Thank you.
 
Sernish - If you're asking about the return line, it does NOT have to be a "hard" plastic hose. Any kind of vinyl or neoprene hose should work fine. There is NO pressure held in that hose. You should be able to find a suitable replacement at ACE hardware.

Now, it's possible the existing hose on your trailer has become "hardened" due to age. This is a normal condition with some plastics.

- Jack
 

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