Can't Remove Hydro Couplings

   / Can't Remove Hydro Couplings #1  

Tom_H

Veteran Member
Joined
Mar 27, 2004
Messages
2,457
Location
20 mi SE of Sacramento, CA-rural
Tractor
Kubota BX2200
I have a BX2200, purchased new in 2000, with 274 hours. I probably have about 50 hours on the FEL.

Recently the two lower hydro couplings to the FEL began leaking some. I noticed that they were a bit loose at the couplings and on one of the male ends found indentations made by the ball bearings in the inner ring of the female coupling.

The couplings are Snap-Tite brand, male piece is part #9840-2 and female is #9840-3. I went to the dealer and got three new couplings. These are made by a different manufacturer; they don't carry the old ones any more.

I cannot get the old couplings to budge from the threaded brass tips on the end of the hoses. I used a 12" crescent and a 15" crescent. I tried putting one on the threaded tip crimped to the hose end and the other on the coupling. No movement. (I checked repeatedly to be sure all torque was being applied in a counter-clockwise direction. I double checked the angle of the threads to be absolutely certain torque was being applied in the correct direction and to be sure I wasn't dealing with some strange threading designed in the opposite direction like a turnbuckle or race car lug.) I then noticed that there seemed to be a piece at the bottom of the coupling that might be a lock nut. The thing is, the interface between the main body of the connector and this lower piece are not completely planar. The two pieces seem to have complimantary faces that are slightly undulated. When I tried to rotate the main body and lock nut away from eath other, I was able to get a rotational difference of about 5 degrees. Because of the non-planar undulated surfaces, this caused the high points of each piece to wedge against each other. Further rotation was seemingly impossible and would only have locked the two parts more tightly. I rotated them back to the original positions, such that the 6 hex surfaces were again parallel planes and the undulating surfaces again in between in complete contact in all portions. (The new couplings sold to me by the dealer do not have these lock nuts; the dealer recommended a bit of teflon tape when attaching the new couplings.)

I cleaned everything really well, applied WD-40, and waited an hour. I then tried putting the 12" crescent on the threaded nipple crimped to the end of the hose, and with the 15" crescent, I tried to fit the center of the seam between the lock nut and the main coupling body right in the middle of the crescent jaws. I hoped that this would apply torque to both portions equally and not wedge them against each other. Both crescents were as snug as possible and I laid everything on a small piece of plywood on the front tire. I tried to apply greater torque. The crescent on the end of the nipple on the end of the hose began to deform and round over the angled brass corner of the hex. I decided it was time to stop and get advice or just haul the whole thing to the dealer.

If any of you have information about this problem I would appreciate it very much. If you know of old threads in the archives where this was addressed before, a link to them would be great. Thanks very much in advance.
 
   / Can't Remove Hydro Couplings #2  
Tom,

I am sure you have already done so, but do not forget to relieve the hydro system pressure to get the couplings to loosen (engine off, rotate fel control through all positions several times).
 
   / Can't Remove Hydro Couplings #3  
Don't use crescent wrenches. Get two wrenches that are the correct size and position them that when you try to squeeze them together, that the fitting will loosen. I use a tubing wrench on the one that has the hose. The better the wrench fits, the easier it is to take off. I don't like crescent wrenches for anything other than a emergency tool. I have had some fittings that are extremely tight and in those cases, I have to hold one wrench against the concrete or other hard surface and rap on the other wrench with a dead blow hammer to get them to start loosening. You can also purchase those fittings from a Parker Hydraulic dealer. The original BX used a different type of connector than the later BX tractors. Don't know when the change was made, however, I have seen that on a few tractors.
Dusty
 
   / Can't Remove Hydro Couplings #4  
I recently had to change some hoses on my tractor and had a similiar problem. I had to use the proper wrench, held in a vise, to loosen fitting. I honestly thought I was about to strip the threads when it slowly broke loose. Be careful with the crescent wrenches, as stated before as they tend to open up and round things off. I also believe that " Crescent Wrench" is synanomous with 'Busted Knuckles"!!!
 
   / Can't Remove Hydro Couplings #5  
Forgot to mention, what the dealer will charge you, will more than pay for two quality Craftsman wrenches at Sears. If the fitting is badly buggered, then use a Vicegrip to get it loose. It isn't like you are going to be reusing it again. The fittings are put on using pipe dope. Sometimes they use Teflon tape, but be extra careful that you don't get any tape near the end of the fitting where it can get into the hydraulic oil system. The two just don't mix.
Dusty
 
   / Can't Remove Hydro Couplings #6  
The male end on the crimped hose fitting is probably NPT threads. Do not use teflon tape on these types of fittings. Teflon paste is the proper thread sealant to use and can be found at almost every hardware store. You do not want pieces of teflon tape floating around in your hydraulic system.
 
   / Can't Remove Hydro Couplings
  • Thread Starter
#7  
I did try using standard box wrenches prior to going to the crescents. The standard wrenches were shorter and thus I could not generate enough torque with the shorter handles. That's when I went to the longer crescents because of their long handles. These things are so tight it's like they're fused. The other two are mated to metal tubes on the side of the cowling. Those will be even more problematic than the one on the hose. I tried one of them but it was fruitless. I guess I need to get a couple of lengths of steel pipe to use as extenders on the box wrenches in order to generate enough torque.

Would applying a little (very little) heat with a propane torch help any? Is the extra piece actually a lock nut, and has anyone ever seen one with the undulated surfaces like I described?

ANY other suggestions/comments are welcome and appreciated.
 
   / Can't Remove Hydro Couplings #8  
TOM,
Can you post a picture of this on here so we can actually see what your looking at?As DUSTY said most of our tractors are different,so it would do no good to go out and look at ours.
ALAN
 
   / Can't Remove Hydro Couplings #9  
Tom

I have had better luck loosening parts with a product called PB blaster it seems to a better job than wd40 on rusted bolts and things like that
 
   / Can't Remove Hydro Couplings #10  
Gave some more thought to this, and realized that the 2000 BX used the first design quick disconnects. Putting some heat on them wouldn't hurt if you have the proper size wrenches to get them off. You might try heating it slightly, only enough to get it hot to the touch, but not hot enough to burn the oil or hose. Then let it cool and try again. The heat might be enough to break the "seal" that is holding them together. A well equipped shop always has an assortment of different size pipes in assorted lengths just for this purpose. Just remember, don't force it... get a bigger hammer.:D
 
   / Can't Remove Hydro Couplings #11  
I am not sure if you can do this or not as it requires the hose and fitting to be completely off the tractor and back in the workshop. This is how my local hydraulic shop gets stuck fittings out. I watched him do it to my 43 year old dozer spool valve to get the outlet fitting off. I had previoulsy tried everything including an 18" adjustable cresent wrench and a 2" open end box wrench (yes, the fitting was 2") and plenty of PB Blaster with absolutely no success.

He placed the valve on the bench, took a flat nose cold chisel and rapped the fitting hard, twice, on 2 different flats. The fitting came right off. He said it was the shock that did the job.

As always, your mileage may vary.
 
   / Can't Remove Hydro Couplings
  • Thread Starter
#12  
MadReferee said:
He placed the valve on the bench, took a flat nose cold chisel and rapped the fitting hard, twice, on 2 different flats. The fitting came right off. He said it was the shock that did the job.

Wo, you guys've given me a bit to think about. Hmmm, have to ponder this a little. Don't want to destroy anything. May be worth the $ to take it to the shop and watch how they do it, then copy them the next time. Could be cheaper than doin' it the wrong way on my own. Knowledge is power... and $.

Thanks for the feedback guys.
 
   / Can't Remove Hydro Couplings #13  
Mad has a good point. I remember when I used to work in a steel mill with real mechanics. They would take a 5 pound hammer and rap on something nice and hard and it would come loose very easy. The first time I seen that done I spent about an hour getting a 2 inch hydraulic line loose and got no where. They sent a real mechanic down to help me and he hit the union with a 5 pound sledge twice then the union came loose with no effort at all. That might be a good idea to try that. I wished I had thought of it.
 
   / Can't Remove Hydro Couplings #14  
Loctite makes a special sealer for hydraulic fittings. Helps stop leaks and doesn't contaminate the system like teflon tape. It, or something similar may have been used originally. That would explain why your old fittings are so hard to loosen. Manufacturers do everything they can to prevent hydraulic leaks. Leaky hydraulics are a major warranty issue.

A good solid whack or some heat will probably break it loose. A proper wrench is an absolute necessity.
 
   / Can't Remove Hydro Couplings #15  
Old thread, I know.
I had been searching for topics on thread sealants when I came across this.
Not that I am a RICH man, but I do have a decent motorcycle and there are 5 bolts holding the rear wheel to the rear hub. They have a pre-applied thread sealant and the owner's manual says to apply heat to remove them. I read that after I had removed them with a LOT of force, probably too much for that sized bolt. I don't remember the exact temperature, the owner's manual isn't handy.

FWIW, etc.
 
   / Can't Remove Hydro Couplings #16  
Last week I took off one of the same quick couplings to attach a pressure gauge for a hydraulic system pressure check. This is on a BX24 that sleeps inside so no corrosion. I used the proper wrenches (Snap-Ons) and put all the torque the fitting could stand. It started twisting the area the wrenches were contacting. Not rounding, actually twisting. I ended up using 2 large high quality Crescents since they are thicker and engaged more metal. Lots of strain but the fitting came loose. There was no evidence of any pipe dope, teflon tape, teflon paste... My guess is one of the thread sealers like LocTite. Acted more like epoxy or Silver solder?!?!?
Tested the pressure, re-installed the fitting and no leaks. Definitely the hardest I ever turned a 1/4" NPT fitting!
 
   / Can't Remove Hydro Couplings #17  
I know that some LocTite has to be heated to release. Good luck and let us know what works.
 
   / Can't Remove Hydro Couplings #18  
I have a suggestion that I used when removing spark plugs. Because I couldn't get a good angle to get them loose, I decided to break out my impact gun! Wham that came right out!

That might work on the female ends, now for the male ends, that's a different story.
 

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