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purging air from Bush Hog front end loader

8762 Views 7 Replies 5 Participants Last post by  DHogan
First, I want to say one thing about this site, I was turned on to it a short time ago and man I'm sooooooo glad. Everybody here has been extremely helpful with my questions. This is a great site.

I've pulled the front end loader off my Yanmar 187, the loader is a Bush Hog 1840QT. I'm refurbishing it because it has a fair amount of rust on it. I had to disconnect one of the hydraulic rams to clean it up, I'm working around the remaining three. When I'm finished with the refurb I'll need to purge the line of air...how do I do that?

Many thanks,

Dave
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Well now....

I've heard a few thoughts on this one...

The way it's done in many industrial systems is each end of the cylinder has a bleeder screw. You just crack the screws open and cycle the cylinder a few times until no air comes out.

Since I've yet to spot bleeders on any of the tractors I've looked at, I'd suggest the next best, which is to ever so slightly loosen the hose fittings and then cycle the cylinder a few times.

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A WORD OF CAUTION: do a google search on HYDRAULIC INJECTION INJURY
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I'm sure you don't want that type of injury! Be careful working with any hydraulic system as high pressure leaks can easily penetrate the skin!


If you'd rather try a more cautious route, you may be able to purge the system satisfactorily simply by hooking it up and exercising it a few times to its limits.
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i have never worried about getting air out of the system when ever i have to replace a hose that has blown i simply replace the hose and use it but it dose usually take a few cycles of the cylinder to get the air out and for everything to start working right again
i have never worried about getting air out of the system when ever i have to replace a hose that has blown i simply replace the hose and use it but it dose usually take a few cycles of the cylinder to get the air out and for everything to start working right again
:ditto:

Cycling the cylinders full stroke 3 or 4 times works for me when I change out a cylinder. I use the same method to execise the system on start-up at sub freezing temperatures.
:ditto:

Cycling the cylinders full stroke 3 or 4 times works for me when I change out a cylinder. I use the same method to execise the system on start-up at sub freezing temperatures.
I posted this last night, not sure what happened.

I found a manual from a similar loader on the bush hog site, they recommend doing it about the same way.

Extend and retract both sets of cylinders beginning with short strokes. Gradually increase the length of stroke until cylinders “bottom out in each direction. Hold valve open with cylinders “bottomed out” for 3-5 seconds. This will purge air from hydraulic components.
Well, I just finished putting it all back together and I'm happy to report that the loader still works :trink40:

Absolutely no issues, did just as the manufacture recommended...life is good. Now I can go play in the horse manure with my new paint job. :fing32:
Glad you are up and running! Now :wwp: If you need easy Picture help
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Here you go.

I'm trying to prioritize the work to clean it up. I did the ROP first but some of the mounting holes are striped so I need to tap them out again before I can put that on. Still a work in progress but it's getting better.

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