755 backhoe Blown a hose

Never change a hydro hose before. Looks like the lower hose for the dipper. (second from the left)

Is it best to just remove it and take it somewhere for a built replacement? is there a better option?

Also, the fluid leaked while I was moving it into the barn, Looked somewhat normal at first, but then got really milky looking. I doubt if it has ever been changed.

What's the best way to clean the system, of old fluid?

Get about 20 gallons of fluid (here you CAN use 134D, but plain old, usually cheaper, hydraulic is fine) and the nose package filter (755 implies 4500 as a platform, AFAIK, but I suppose it could be something else.)

Take off the grille. Drain about 4 gallons out of the nose above the pump. There is a plug on the fitting. Undo 4 bolts and find the screen that's in the fitting at the top of the hose leading to the pump (bottom of the nose sump) take it out and clean it, replace.

If your power steering comes from the nose sump, pull that screen out and clean it. Replace. If power steering is on the pump, don't worry about that, it doesn't apply to you.

Pull the big round top cover, replace the big pleated filter.

Go down to the bottom of the subframe on both sides, find plugs, dump about 7-8 gallons per side.

That's the bulk of it - you can't really get "it all" without disassembling everything, draining every hose and cylinder, which is impractical.

Button up the system (fix your hose somewhere in here) and start pouring fluid into the nose reservoir through the big filter hole. Get it up onto the dipstick, wait a while, recheck. Crank a bit, recheck, top up. Start it up, move the hoe and loader around, recheck, top up...

Unless you love doing this sort of thing and have a really bad case of penny-wise-pound-foolish, strongly consider replacing the whole set of hoses next to the one that actually blew - they are probably of an age, and the rest will follow soon enough. In my case two were obviously much newer, so I left those two alone and replaced the other 4 when I blew one. Keep track of which hose goes where. Keep everything clean. Aluminum foil can be useful.

You'll have to check your local supply options to see if it's cheaper to get hoses as parts from New Holland or have hoses made up locally at a hydraulic shop.

I don''t think a 755 is on a 4500. Sounds like the model of the whole machine.
That is a totally different critter, I believe, and I can't help very much on those.
If you are talking about the hoses that go from the tractor into the boom, it might be wise to bite the bullet and replace them all, unless some of them look quite new. That is not a chore you want to do again any time soon.

Maybe someone who knows better than I will chime in on this.

Myron

755 was the model of a TLB tractor made from 1978-1983, but it was also the model of a backhoe attachment that was made from 1965-1980, and was used primarily on the 4500.

Ecnerwal may be right. I have a 4500 with a 755 on it (the largest hoe offered). He is also dead on about the screens. My 4500 also uses the frame as a fluid storage tank and there is a drain on the lowest part of the left frame on the inside. Also, if you drain the milky fluid into 5 gallon pails and let it sit for several months the oil should seperate so you can pour it off the top.
One other PITN I noticed about mine (yours may be the same) is that the return hose (to the main tank) dumps fluid right on top of the filter. When the fluid is cold and the filter pressure bypass spring kicks in the dirty fluid dumps right past the filter into the screen. My screen was always clogging up. I built a little plate on top of the filter to deflect the fluid to the sides. I also drilled a new hole in the filter rod so I could double the pressure of the bypass spring. Have never had an issue with the screen clogging up since.

Jim

Sean, you are correct.
I was thinking that the large hoe on the 4500 was a 750 or something else, and visions of the larger 755 TLB came to mind first.
I have done the hose replacements on my 4500, and it wasn't really a fun job. About the only way is to remove the hoe from the tractor first..
There were a couple of quite extensive threads on that exact subject on this forum a while back. If you can find those, it will help greatly. (Especially the part about making your own special wrenches for the job.)

Myron

750 is the 10 foot hoe

753 is the 13

755 is the 15

While the potential for confusion with entire machines that have the same number exists, those are the hoes from the late 60's early 70's. The 4500 is the only supported platform for the 755, while the smaller hoes are supported on other tractors. In a spate of "after I replied" insight, I also looked at plowjockey's other posts, which suggest that a 4500 is what he's got, unless he got something else in the meantime.

(quoted from post at 18:39:21 10/01/13)
Is it best to just remove it and take it somewhere for a built replacement? is there a better option?

Click to expand...

There's probably a cheaper option. You can get a replacement hose online, for a little over $60. My local shop wanted at least $25 more, so it will depend on how quickly you need it and how many hoses you decide to change. The part number for the six big/main hoses is D8NND558EA (aka LBP 291016).

I can't find the manual right now, but does anyone know what the fittings are, the approximate length, the ID and PSI rating for that hose?

Surplus Center has some good prices,just need to make sure they are the right stuff.