I’ve got a 45’ Eagle towable manlift and bottom boom is leaking down.

[wdchyd]

Ok so why would there be two identical valves like that? One for up and one for down?how do these valves work? And what would you do before taking it to a shop or buying new valves? And lastly, how would I know which one is actually causing it?

So, these valves are adjusted and tuned to suit manufacturers requirements for each direction. Two choices when replacing these, buy the preadjusted OEM cartridge valve from the lift manufacturer and plunk them in, or pretest existing valves on your existing cylinder (with known good new seals installed and bled) to witness the factory adjusted pressure, then install new counterbalance valves and adjust on test stand while cycling cylinder off machine. Adjusting your existing cartridge valves blindly can result in bad things happening. Finding the problem valve would require a cartridge body on a test stand or ……hit or miss

 

[Puppypunter]

Yep your right. I ended up and bought two sun valves. The guy I talked to was Trey of precision hydraulics out of Odessa tx. Real nice guy but when I was giving him the numbers off the valves I gave him the first 7 numbers and started to give him the last 4 and he said “the first 7 is all I need, the last 4 don’t mean anything” so I pushed back on him and said “well they got to mean something, these valves look adjustable, are you sure the last 4 aren’t what the valve is adjusted to” he assured me I would be good to go. I knew it was very unlikely that both valves went bad at the same time and I was wanting to order just one, but the guy that works with me saud let’s just get both of them that way it’s done and we can get to work. Do I bought two, had them overnighted. Got them, put them in. And still leaking down! I guess I’ll try the rest from above to see if the cylinder is leaking internally, this sucks though, out 250 dollars with no change.

 

[Puppypunter]

Ok so am I right I’m thinking the last 4 digits may point to pressure tge valve is set to? This lift manufacture is no longer selling parts, I do believe they are stilll in business after multiple bankruptcies and sell offs, but they no longer carry parts for these lifts. So should I put the old valves back in and then get a fork lift to do the test you’re talking about? Or should I just go ahead and keep the new ones in? How big of a chance do I have that these new valves will be set close enough? Like does it have to be absolutely perfect? Cause there isn’t even a hydraulic shop within 60 miles of where I’m at, I live in an oil patch but the primary shop that was really good and open for 30 years retired and sold tge business, then about a year later they went out of business because the new owners were sooo terrible.

 

[oldnslo]

I suspect last four digits are just a date code and have nothing to do with setting. On previous post you stated 2500 PSI. Was that marked on the valves or where did the 2500 PSI come from? Per Sun the standard setting on CBCA LAN is 3,000 PSI so slightly higher than 2,500 PSI but should work fine if they were not adjusted from standard factory setting.

 

[wastenot]

hey fellas just found this forum, I’ve had an extremely hard time finding a proper forum for hydraulics, and I’d appreciate your help.

I’ve got a 45’ Eagle towable and it’s just yiur simple boom lift, with manual outriggers and hardly any electronics at all. And a Honda engine running it and that’s it. Nice and simple it’s got a bottom boom and the top boom with left and right on the turret.

The problem is I think it’s a 1996 but the company was sold several times so I haven’t been able to locate any kind of manual however I did talk to a guy and he sent me 4 pages of info including the hydraulic schematic.

The bottom boom started leaking down slowly and when I use the bottom controls it goes up really fast but it still leaks down. When I use the top controls it’s always been really slow and it leaks Down as well.

I’m guessing it’s tge top controls because I’ve had them leaking for awhile slowly by the orings on the three spool valve. When u take it apart the spools look kinda worn, they aren’t real sharp and they just look alittle worn.

Do y’all think that sounds like a valve problem? Because the cylinders were repacked 4-5 years ago. The cylinders aren’t leaking anywhere.

What kind of valve is it that I need for the top 3 spool control (top and bottom boom, and left snd right.) are these cylinders double acting on the booms and what about the turret, it’s got a rotary motor on it ti turn it, would that be a different type? Here’s the schematic.

I don’t know what type of spool valve to order and I have no idea how many gallons per minute it should be either. Like I said the top controls are pretty darn slow, I realize the top controls are usually slower for safety but any insights into that would be appreciated.

It’s got a n 9hp Honda engine on it with a 5 gallon tank. Thanks again for any help I can get in this matter.

AmerEquip made multiple versions of your lift. Originally, there were no external check valves. In later years, they included up to three. Its always good to check valves besides the ones inside the hydraulic cylinders.

Did you see fluid near the spool (valve) handles before you removed them? or, did you hypothesize that this is where you were getting back-flow?

You likely have controls made by Walvoil. Unless you have a lot of water in the hydraulic fluid, the block should be in good shape. If the chrome finish on the spools have flaked off, then these need to be replaced. If not then just replace the sealing washers.

It important to match the spools and their components to your specific block. Next to one of ports in the block will be two engraved numbers. Take these numbers and call: 800-219-6993. They can match the parts you need with your block.

If you email me directly, I'll email you some schematics of the hydraulic system. wastenot@aol.com.

 

[Puppypunter]

I suspect last four digits are just a date code and have nothing to do with setting. On previous post you stated 2500 PSI. Was that marked on the valves or where did the 2500 PSI come from? Per Sun the standard setting on CBCA LAN is 3,000 PSI so slightly higher than 2,500 PSI but should work fine if they were not adjusted from standard factory setting.

Yes the valves both said 2500 psi. So if I do the above test and use a forklift to support the weight, shut off engine and disconnect hoses, what does it mean if fluid comes out of the ports? How will I know if it is leaking internally?

 

[oldnslo]

Puppy
If you are doing the leak down test with hoses disconnected you would have to know which side of the cylinder is supporting the load.

If base end then oil leaking out that hose would indicate a leak in the load holding valve. If base end and oil leaking out rod end hose the cylinder is leaking.

If rod end supporting load oil leaking out rod end hose would indicate leak in load holding valve. If no oil out either hose or oil out cap end then cylinder is leaking.

 

[wdchyd]

Knock, knock, knock…….did anyone read post number 39?
You could’ve saved yourself $250.
I do this stuff for a living so I’m not just guessing.

(……and don’t throw out your old valves, you’ll need them to help adjust the new ones proper when testing off the machine)

 

[oldnslo]

Knock, knock, knock…….did anyone read post number 39?
You could’ve saved yourself $250.
I do this stuff for a living so I’m not just guessing.

(……and don’t throw out your old valves, you’ll need them to help adjust the new ones proper when testing off the machine)

Yes and seems like we are repeating ourselves. Not sure where puppy is located but fully agree he is not checking to verify before replacing components.

 

[Puppypunter]

Hey guys I appreciate all your help and I’m sorry if you feel your repeating yourselves, however I must have not have seen the leak down test before deciding in buying the valves, in post 22 I specifically asked what can I do to test it to isolate the problem, I didn’t see the leak down test until after I decided to buy the valves.

Si today I had a forklift hold the boom, turned off the engine and disconnected both hoses, the boom leaked down just as fast as he let it down with no oil coming from the ports whatsoever, does this mean it’s leaking internally? We did this with the new valves in, I didn’t have the old ones on me at the time and after reading oldinslo said that it should be adjusted to 3000 new and that should be close enough to 2500, we went ahead and tested it. My buddy asked could it be something to do with the pump, however it lifts and holds the top boom just fine. Again it’s not leaking externally and not a drop of oil came out when he set it down.

Thanks again for all your help