New Hydraulic Lines

[lundwc16]

The slides on our 2010 Montana are hydraulic & I'm getting ready to replace the lines on all three slides. I have the underbelly down, & have the bedroom slide ram exposed, & old lines measured & new lines made. The question is after installing new lines, how to bleed the system?
Thanks, John

[Carl n Susan]

I believe they are self-bleeding. Just run them in and out without letting the hydraulic tank go empty.

[lundwc16]

Originally Posted by carl n susan

I believe they are self-bleeding. Just run them in and out without letting the hydraulic tank go empty.

Thanks for the quick response. I thought that when the slides retract & the fluid is sent back into the tank, air trapped in the system would go back to the tank also, & just bubble up. Depending on how far I get in the heat we have been having I'll let ya know Tues. or Wed.
John

[lundwc16]

Well we aren't ready to hit the road yet, but got all the new lines hooked up today & the slides working. The above advice was correct & the system bled itself. Still wires & underbelly hanging down, but it's 88 deg out & I had enough of crawling around under the Montana for today. Thanks car n susan
John

[McRod]

Where did you get your lines from/made?

[h2ojocky]

I ordered mine from Lippert.

[lundwc16]

I took the shortest one, which went to the bedroom slide, to a local shop that makes hydraulic lines. I took that line for a sample of size & type of fittings, & measured the other lines I wanted made for length. Made the new lines while I waited.
John

[McRod]

When you take one off, do you need to cap it off so hydraulic fluid don't go everywhere?

[lundwc16]

I did not as it wasn't under pressure, I did the job with the slides closed, if you do it with the slides open, then the rams will be full of fluid, & that may cause fluid loss.
John

[mlh]

Why did you replace all of your hydraulic hoses?
Lynwood

[Mikendebbie]

I quizzed Lippert on replacing a jack leg and what to do with the hoses when disconnected, and they said to keep the ends up and don’t let them drop because the fluid would run out, and try to have the parts in place to quickly install and hook the hoses back up.

I am way over my skis here in giving advice on a hydraulic system, but it made sense to me that a low end of a hose would siphon or provide a low point for the fluid to leak out of the reservoir. I will let you know because I think the curbside rear jack leg I bent last year will go out on me someday. For now I have it back to fairly plumb and it is working correctly every time! Knock on wood!

[lundwc16]

Originally Posted by mlh

Why did you replace all of your hydraulic hoses?
Lynwood

I replaced 4 hoses because two of them that were frayed & leaking went to rams at the rear of the trailer. That required most of the underbelly to come down for access. At various points along the way they are zip tied to the frame & or wire harness so they can't be pulled through. As long as the underbelly was down I decided to replace them all. I'm a couple clicks north of 70 & it's not a job I want to do again on my back.
John

[h2ojocky]

I replaced mine because when I was having some welding done on my grey tank support some slag fell on the hoses and ruptured both lines. The hardest part was R&R of coroplast. I ran the new hoses inside pvc so if I ever have to replace them again I can just pull them through the pvc.

[mlh]

Originally Posted by lundwc16

I replaced 4 hoses because two of them that were frayed & leaking went to rams at the rear of the trailer. That required most of the underbelly to come down for access. At various points along the way they are zip tied to the frame & or wire harness so they can't be pulled through. As long as the underbelly was down I decided to replace them all. I'm a couple clicks north of 70 & it's not a job I want to do again on my back.
John

Thanks!
Lynwood

[dieselguy]

Our cylinders will always have some oil in them whether retracted or extended as it takes fluid pressure to move them either way. When retracted, the rod side of the cylinder will have less oil as the rod itself displaces some of the volume of the cylinder. Unless you cap the lines themselves when you remove both ends from their fittings, you'll get some mess as there is nothing to hold the oil inside ... it's unavoidable.

[lundwc16]

At the shop where I had the new lines made I asked for plugs & caps for the lines & rams when I disconnected the lines. They had both & gave me 4 of each. The biggest mess came from the fluid that was in the old lines as I was removing them, until my old brain remembered I had the plugs & caps.
John