leaking hydraulic cylinder

johnpeace

Member
Joined
Mar 20, 2010
Posts
29
Location
NE Georgia
I just bought a 1988 HiLo and LOVE IT!

We got it home and raised the roof to demonstrate to the family some of the features. While we were taking a look I noticed a few details that I either overlooked during the pre-buy inspection or that weren't present then:

1. The upper/lower seal is not being made...the top doesn't raise enough to come into contact with the seal. The pump runs, the top half lifts until the safety lock engages with a 'thunk' and then the pump squeals like the owners manual says...but the top doesn't lift all the way to make the seal.

2. When I folded out the top bunk and propped it up on the legs, it was out of level...further confirming my suspicion that the top half is only telescoping to within about 3" of 100%.

When I went outside and inspected the exterior, I found an alarming puddle of hydraulic fluid underneath the cylinder.

Whoops.

So, I'm looking for the most efficient way to repair this.

It looks like the pulley plate that slides on the guide rod during extension has moved further than it presently is. I'm thinking that maybe the hydraulic system, if it's leaked during several lower/lift cycles, may be low enough in fluid to not have enough to complete the last 3" of roof extension.

I can see the pin that mounts the cylinder on the stationary end and that the other end (the piston) is threaded to the pulley plate. I can envision how you might lower the top onto 2x4s on end to take some tension off the cables and remove the cylinder...it probably just needs new seals.

Has anyone here been through this before or have any input?
 
Hydrolic leak

It sounds like you have 2 problems:

1 First you need to address the hydrolic leak. You need to go under the trailer and inspect the system. You may need to have some one runn the roof up and down as you look for the leak.

If it is a hydrolic line leaking, It is a simple matter to replace a line, you can get a replacement from Hi-Lo or simply take the line to a hydrolic shop and have a replacement made.

If it is a hydrolic ram you can have a seal kit installed, I would suggest you take it to the dealer as this does take skill to replace the seals. This should take about 2 hours of labor and a seal kit about $25.00, It has been about 5 years since I priced a seal kit.

If it is the pump, or resevor you can get replacement parts from Hi-Lo and easly do the repairs your self.

2 You need to ajust your cables, There is a step by step on how to ajust the cables posted on this web sight. It is a easy self repair.

Sam
 
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I'm pretty sure it's the cylinder/ram that's leaking and it's leaking fast. I had a big puddle of hydraulic fluid under the cyinder after raising the roof.

It looks like I need to remove the cylinder/ram from the trailer to take it to a hydraulic service/repair shop to have it rebuilt.

The ram end is threaded onto a steel plate that has the 2 pulleys on it. The stationary end is pinned in place on the chassis.

What's the procedure for removing that thing?
 
johnpeace -

Here are the library links for the information on adjusting the cables. This will raise the top and give you a proper seal.

There is a section on adjusting the cable in the owner’s manual,
http://www.hilotrailerforum.com/f49/owners-manual-2004-hi-lo-78/, don't worry about the year model.

Here's a document that was written by a Hi-Lo owner,
http://www.hilotrailerforum.com/f61/cable-replacement-adjustment-1998-24td-125/

We don't have a document in the library for removing the hydraulic cylinder yet and we could really use one. What would be great is after Sam tells you in general how to do it, you could make a few notes to fill in any small details while you did the work. Optionally even take a picture or two. Then If you'd send me the procedure and the pictures I'd make them into a PDF file and add it to our library, giving you, Sam and anyone else credit of course :)

Neal
 
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I have a call in to the factory and am hoping to talk to someone there tomorrow. I'll get their input on cylinder removal and if it sounds like something I can do myself, I'll give it a shot.

I'll be sure to take notes/photos during the procedure so we can add it to the knowledgebase.
 
Lame me...
I got so absorbed in the work that I didn't take any good pictures.

I did learn a fair amount though, and have it all finished, put back together and working beautifully!

Here are some quick takeaways:
1. The guide rod is a pain to get out and back in again. The trick to this is to un-pin the stationary end of the hydro cylinder so you can rock it around a little and align the guide rod with a clear space through which to extract it

2. The lowering solenoid on my camper wasn't making contact with the release valve stem. I turned the adjustment bolt out a few turns and voila, it lowers with the switch now!

3. My cables were stretched beyond the limit that would allow enough adjustment to get the top back as high as necessary to level out the top bunk and seal all the way around. Replacing the cables sounded expensive and like a major pain in the butt.

So, I placed some steel collars/washers around the cables and thought this a very clever way to get another 1 1/2" of adjustment. So now, my cable adjusment nuts rest on a 5/16" washer on a 1.5" collar/spacer. That was enough to get everything nice and level and the top to come up to the seals

If I do have to come back and do the cables, I know now how to do it.

I thought my air conditioner was inop (it is a 1988, after all) but while I was doing the work on the camper I noticed the AC inlet up near the roofline. I plugged an extension cord into this and the A/C WORKED!

I drank a beer in the air conditioned comfort of my Hi Lo very pleased with myself.

When I have the trailer 115V AC cord plugged into 110V (with an adapter)...and then plug the supplied feed into the air conditioner power inlet...it doesn't work. When I plug a 110V extension cord into that inlet, it does.

Cause? Bad AC feed cable? Not enough amperage to run the trailer's AC bus and the air conditioner?

Now I have just a few water issues (leaking toilet, needs replacement parts) to sort out and I'll be in BUSINESS!

Maiden voyage is next weekend to Sequatchie Valley in TN for the Tennessee Tree Toppers Sequatchie Sprints weekend hang glider race series...can't wait!
 

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