Hydraulics Question

[Clarke]

This morning I connected the mini hoe to do some digging to re-locate and plant. After I removed the mini hoe and connected the pallet forks. The ambient temperature changed quite a bit and I could not get the aux. hydraulic lines to connect without relieving the pressure by loosing the hoses at the cylinder. Is there a fitting or a technique that I don't know about to solve this problem. This has happened several times before when hydraulic quick connects had to be changed.

sg

 

[SnowRidge]

Generally, operating the hydraulic controls with the engine off should relieve the pressure. Did you try that?

 

[Clarke]

Yep!!

Doesn't work because it is the implement that is the problem..


sg

 

[SnowRidge]

Hydraulic fluid is not supposed to be compressible, so it sounds like you may have air or moisture trapped in the mini-hoe hydraulics somehow. Is there any chance of that, and if so, is there any way to bleed that implement?

 

[SnowRidge]

One other thought. Does it make any difference if you shut down and operate the hydraulic controls before disconnecting the mini-hoe?

 

[Clarke]

Actually this time the problem was the quick attach cylinder that I had to bleed the pressure off. I connected the mini hoe in the morning when it was cool. I worked with the hoe for a couple of hours in the hot sun. I guess the aux. hydraulic cylinder heated up from the sun and I could not connect the hoses without relieving some pressure by loosening the hydraulic lines. I have had the problem in reverse not being able to connect the hoe after a temperature increase.

sg

 

[stray]

Once I left the mini hoe in the sun and it build up pressure and I had to manual relieve it. I have used a technique to relieve the pressure off these lines and it works quickly and easily. If it is a male line just take a light hammer or something and rap it right on the end. If that don’t work rap a little harder. It will work. If it is a female connection use a flat ended punch and something to hit the center button inside the quick connect. If that don’t work rap a little harder. It will work. Stay in the middle and straight with just a little care you won’t hurt anything.

 

[Bird]

Craig, we've talked about this in the past, but I did the same thing as you, except I put a rag around the fitting first just in case it should try to squirt any oil out. Of course you don't squirt enough out to amount to anything, but I never wanted to take a chance on any hitting me in the eye. /forums/images/graemlins/wink.gif

 

[stray]

Good idea about the rag. I ware glasses all the time so i didn't think about that.

 

[MossRoad]

I had the same problem with my snow plow. Could not get it connected for the life of me. The first time it happened, I cracked a fitting to relieve thepressure. After discussing it here and getting the same tips you have just been given, I now use a large bolt to put against the pin in the fitting, use a rag to hold the bolt and whack the bolt with a hammer. Only a drop of oil comes out, but that is all it takes to relive the pressure.

Does anyone know, while you cannot compress a fluid, does it still expand and contract with temperature? That is the only thing that I can think of that would have caused this. I parked it in the sun for few hours and that is when it happened. I now make it a point to wiggle the aux PTO lever both directions a few times before shutting down and disconnecting. It has never happened since.