Backhoe Backhoe hose couplers won't mate

Tractorganic · Aug 20, 2006

I can't get the couplers on the hydraulic hoses to my 758C backhoe to mate up with the tank port (rear) and power beyond hose (underneath). I tried toggling the FEL valve to release presure but, hard as I push, they won't stay together. It seems they are just a hair short of joining and clicking in. The couplers are relatively clean and undamaged. The manual isn't much help on this. Anyone have experience with this hookup? I just went thru two changes of clothes struggling with this in 80+ degrees and river valley humidity!

RickB · Aug 20, 2006

The heat has caused a buildup of pressure in the hoe's valve body and hoses. This makes it difficult if not impossible to couple the hoses to your tractor. Cleanest way to solve this problem is to loosen one coupler (the male may be easiest) enough to release about two tablespoons or so of oil; relieving the pressure. Be sure to loosen a fitting on either the IN or OUT hose, not one going to a cylinder. Not terribly unusual for hydraulic attachments that sit out in the sun and tractors that have couplers WITHOUT the capability to couple under pressure. But you will never hear a sales guy talk about it prior to getting your autograph! Bradco hoes have a small bleeder valve dedicated to solving this annoyance. Another thought; you aren't trying to couple these hoses up with the tractor running, are you?

gordon21 · Aug 20, 2006

Is this the first time you have tried to hook it up? If so, you probably don't have the right connectors. They all appear to be the same size and shape, but there are literally dozens of types. There are three different 1/2" JD quick disconnects alone. Times 2 for male and female and you have 6 for the 1/2 size. Then there are other JD sizes and lots more mfgrs. JD has some ends that are almost a 90 degree angle and some that are about 40 degrees beveled. The lengths on some are different by about 1/4" I am guessing that is your problem. You may be trying to insert a non beveled male end into a female coupler that needs the bevel or trying to use a male end that is 1/8' or 1/4" too long. I just went through this ordeal hooking up my log splitter to the power beyond couplers. I finally had to go to a custom hose shop to find the fittings I needed. Parker is the leader in fittings and they make hundreds.

If this is an old previously working setup, relieve the pressure by pressing the very tip of the male ends on both male hoses with everything shut off. Use eye protection and gloves and point the end away from you.

JerryG · Aug 20, 2006

gordon21 said:
If this is an old previously working setup, relieve the pressure by pressing the very tip of the male ends on both male hoses with everything shut off. Use eye protection and gloves and point the end away from you.

If you do it this way, wrap a shop rag around it then push on the end. The rag will keep the oil from going all over everything.

PineRidge · Aug 20, 2006

Tractorganic said:
I can't get the couplers on the hydraulic hoses to my 758C backhoe to mate up with the tank port (rear) and power beyond hose (underneath). I tried toggling the FEL valve to release presure but, hard as I push, they won't stay together. It seems they are just a hair short of joining and clicking in. The couplers are relatively clean and undamaged. The manual isn't much help on this. Anyone have experience with this hookup? I just went thru two changes of clothes struggling with this in 80+ degrees and river valley humidity!

I had exactly the same thing happen the 1st time that I tried to connect the hoses on our NH backhoe. Rick gave you some good advice although I just rap the tip of the male connector with a hammer after I put a copper cap on it to prevent damage and keep the oil off me and out of my eyes.

Tractorganic · Aug 21, 2006

To clarify: I have about 150 hours on the hoe and it's been dismounted and in th shade under a tarp for a week while I did log winch work. The TC40D was shut off and the FEL control toggled around thru all positions to relieve pressure. All couplers are NH original. I even toggled the hoe levers but with no cylinder movement at all. This morning I'm going out there while it's cool and tractor has sat all night to see if they'll pop in. Then I'll know it was pressure in the tractor lines. Next I'll use the your male coupler pressure release methods. Very helpfull! Hey, can I put Bradco release fittings on my NH?

jinman · Aug 21, 2006

Tractorganic said:
Hey, can I put Bradco release fittings on my NH?

A cheaper way is to buy an extra female quick-connect fitting. When you disconnect the hoe, put the fitting onto one of your hoses. It will seep a little, but not that much, especially if you put it in a vertical position. Then the pressure will never have a chance to build up.

Tractorganic · Aug 21, 2006

Good advice! Hoe lines were overpressurized.Used 1\2" wooden dowel, rag and hammer taps on rear female and underneath male and female then hookup was a snap (npi). Had usual solo ordeal aligning subframe w./ tractor and using hydraulics to hook up the hoe (does it ever get easy?). Cleaned all zerks and greased the hoe. Some lines have scuffed rubber so I'll probably have to replace, (Oh boy!). Checked hyd. fluid level: too high! Crawled back under and drained 3 liters and yes I dropped the plug into the slimy pan. It runs as good as ever. Fluid level fluctuations are mystery, no leaks show on ground. Thanks all!

PineRidge · Aug 21, 2006

Some of your fluctuations in oil level can come from connecting implements like your BH that share the hydraulic oil. As you get more familiar with your BH you will eventually get more proficient at connecting it. Here is another route that I took to make the job a whole lot easier. dolly