hydraulic fluid in line - Hi-Lo camper travel trailer forum

Brookside1954 · 02-01-2017, 02:46 PM

While under my rig today with it in the up position, I noticed that the hydraulic lines to the ram are not full of hydraulic fluid. Some places I could see red, and others clear. Is this normal? Will I need to put more mil-h-5606 hydraulic fluid in the reservior?

Formula357 · 02-01-2017, 05:01 PM

I believe that if your top is raising and lowering ok, that your condition is normal. That translucent line is a bypass that I think only has fluid in it if the ram is leaking past the seals. If you check the fluid level or add fluid, ONLY do so with the top lowered.

Larry

Treeclimber · 02-01-2017, 05:17 PM

Brookside1954, Wow, Mil-H-5606! Haven't heard that since I left Naval Avaition. But don't put that in you hydraulic system. Hi Los use Dexron series automatic transmission fluid. Find the earliest series you can, ie, III, IV, V or even VI. I recently had my cylinder rebuilt and they serviced it with VI. Don't quote me, but 5606 is a natural petro product and is used with synthetic seals==tranny fluid is synthetic and is used with natural seals. Keep an eye on how much fluid amasses in that line and for safety, look for a hyd shop that can rebuild that cylinder. my rebuild was about $200.
Tree

piperjim · 02-01-2017, 05:21 PM

A little more of a description, and a hydraulic cylinder diagram, can be found in this thread:

http://www.hilotrailerforum.com/f22/...tic-line-3263/

Look at the 6th post down, from Norton Rider.

Brookside1954 · 02-02-2017, 05:44 PM

Thank you to all for your help with this issue. Alfred

Motoman · 09-07-2019, 10:00 PM

Mý hilo just went down. Before attempting to raise again today I noticed plastic line was half filled here n there. After a failed attempt to raise the top, I crawled under to find plastic line top be fully filled with fluid. I suppose i need to work on hydraulic shop now right??

Treeclimber · 09-08-2019, 06:49 AM

Motoman, As you suspect in both your posts, you have had an internal hydraulic cylinder failure. The cylinder needs to be removed, taken to a hydraulic shop and rebuilt. Testing to 2600 pis with Dextron A/T fluid. And of course, reinstalled.
Check the "search" heading at the top of the page for "cylinder removal".
Tree

Treeclimber · 09-08-2019, 06:53 AM

Moto, Search for "How to remove and replace the hydraulic lift cylinder" About the third one down labeled "Sticky" you'll find some guidance. Best of luck, I've been there.
Tree

auerdoan · 05-08-2020, 10:55 PM

Quote:

Originally Posted by Treeclimber

Brookside1954, Wow, Mil-H-5606! Haven't heard that since I left Naval Avaition. But don't put that in you hydraulic system. Hi Los use Dexron series automatic transmission fluid. Find the earliest series you can, ie, III, IV, V or even VI. I recently had my cylinder rebuilt and they serviced it with VI. Don't quote me, but 5606 is a natural petro product and is used with synthetic seals==tranny fluid is synthetic and is used with natural seals. Keep an eye on how much fluid amasses in that line and for safety, look for a hyd shop that can rebuild that cylinder. my rebuild was about $200.
Tree

Can I just top it off .. is there a way to drain and refill?
Is there a bleed process required? Sorry for that battery of questions .. this is great thread . Appreciate any help

Treeclimber · 05-09-2020, 06:35 AM

auerdone, a little fluid in that plastic line is not a worry unless there is a quantity and it's fresh. This is what is called a static line. When the static line gets to the point like Motomans above, it's time for a rebuild. Normal routine maintenance shows that we need to keep that hyd cyl clean to prevent contamination. Periodic checks should also include checking the hyd reservoir level. When in the raised position, there should be about 1/2" of fluid in there. This can be measured with a popsicle stick. When lowered, about 1/2" from the top. Use Dextron tranny fluid I thru V
Tree