So me and my brother recently purchased a Austin Western RT Crane. Just finished going through the motions of having our mechanic change out all the fluids. Hydraulic fluid, engine oil. Etc. So anyway today while we were moving the crane through its motions to help baffle any air out from the fluid change. The Hoist down stopped working. So I boomed all the way in ln, now the block is all the way at the top. And I cannot boom out without being able too hoist the block down. Information has been slim on these machines. Any feedback would be greatly appreciated.
Most hydraulic winches in crane service have a overrunning clutch/ brake system of some type. They will typically require hydraulic pressure to release the brake allowing the drum to let out cable. Some pictures of the winch would help. Designed so if the engine hydraulic stops, it just doesn't freewheel down. Its possible you have air in the line running to the brake, not allowing it to release. If you had boom telescoped out, when you retracted the boom it should have let cable out, not gotten the block up to the boom tip. If the winch is mounted to the upper house but not the boom, the winch line can get a little shorter by booming down, and longer by booming up.
Ok I'll be sure to get some pictures tomorrow when I'm on site. Thanks for the quick response.
And yes your right, I did raise the block too the top. It absolutely had the block going down, As I was booming in.
Also, the hydraulic reservoir is full. What in your best opinion would be the best way to clear the system of any air? The temperature was rather cold at a -25 C°. Would that complicate this whole process Abit?
Check the hoist rope is on the outside for the entire length of the boom. Just saying.
I really doubt that you have a lot of air in the system. If you just dropped the fluid in the tank, and replaced it, you actually only changed around 1/2 of the oil. There's almost as much oil in the cylinders and hoses as in the tank. Most of that oil didn't run out when you pulled the plug on the tank. If it was all working correctly before the oil change, you shouldn't have much for air problems. The air in any cylinder/ outrigger lines will work its way out when running it. When we change a hose or rebuild cylinders, we just work the cylinder slowly back and forth and it will usually push the air right out. If it was that cold, I've seen the block not come down because the sheaves were frozen, but then you usually will have a big pile of cable all piled up around the winch. I have seen winches frozen also, but if its pulling cable up, it should be letting it out. I looked up some pictures of austin western, and it looks like the winches aren't brake pack style. It looks like they use a worm and screw like the old tulsa winches. The winch can't move unless the screw is moving. Unless I'm not seeing something on the back side of the worm, but it looks like they are just a direct drive worm. Are you sure that the linkage isn't frozen or has water in the valve and its frozen? My galion will freeze the one control valve if it gets cold, it holds moisture and it will freeze up. Does your winch look like this one?
Ok that makes sense too me. I am gonna check the the intake tubes on the pump and the hydraulic reservoir. Cause the main pump is being rather loud. Also the breather being clogged up could create vacuum. And yes that's exactly the style of winch that this crane has.
So perhaps I'm wrong, looks like the hoist hydraulics are Abit different. Sorry I'm Abit new too cranes.
So the blue arrow looks like some kind of drum brake. The red arrow points to a hydraulic piston assembly. It should have spring pressure to apply the brake at all times, and then you should have hydraulic pressure delivered to the piston when you push the lever to "cable down". That hydraulic pressure on the piston, should push the spring pressure away and release the brake. The spring apply to brake the drum may all be internal in the "piston" assembly. If the seals are shot in the piston portion, it can not have enough push to release the brakes. Some of them have a bleeder plug on them also. The brake may be frozen to the drum, or just stuck. There's a lot of oil residue up there so somethings leaking. You should be able to have someone push on the lever and see if the drum rod is moving. You need to pull off those cable clamps off, and install them correctly. The cable goes into the becket alone, and then the "tail" on that style, I just always cut a 6" piece of cable and cable clamp the "tail" to the 6" piece. The clamps shouldn't be on the load line. And really, the cable looks pretty shot anyways, you can see its all bent up and probably rusty. $500 for new cable would give a lot of piece of mind.
Hey thanks alot for all the great information I'll be sure too look into all the things mentioned above. Really appreciate it. Really big deal for me.
Nice post @crane operator
Well you're not to old to learn something. CO I have never seen a tail clamped before, they were always free and have never seen one slip out of the becket unless the wedge wasn't pulled in tight. But that was on cable operated earthmoving equipment including drag lines.
Being you are new to cranes, when you get your new cable ask the rigging supply store for a handy pocket rigging guide. I've been retired for 6 years now but when I was working, they were still free and full of good information. Improper rigging can and has killed many.
The local crane shop clamped the new rope wrong in the becket on the 28 ton boom truck. Even pros mess up and it pays to be extra vigilant.
Had a AW crane forty years ago the Anti Two Block switch would get Cranky, would have to boom the damn thing down and physically reset the switch once in awhile(Jostle between two blocked and not), ended up changing the switch(after five years tormenting it)
Look to see if the brake chamber is moving when you hoist it down
At -28 F here today it would be one of them days that the Grove pickers would have to run for at least a healthy half hour before picking to keep from blowing the winch out when revving it up attempting a pick.
Thanks for all the replies. We got a big cold snap. -50c° some days. So haven't had a chance to try anything. Today is a balmy + 2. So we are going too see what we can do. I will definitely be replacing the cable. And extra rigging knowledge never hurt. Will give an update.
So with the nicer weather the machine seems very happy. Running and working as it should, did this project without an issue. Really appreciate the feed back fellas .
I appreciate your help with all of this, I have one more question if you don't mind answering. Just wondering what weight of oil you would recommend for this hydraulic system?
A aw32 or aw46 would be fine, but just check and make sure it doesn't have ATF in it. If its ATF (automatic transmission fluid) it will be red. The 46 will be a little thick for your winter climate, but wouldn't really hurt it if you are just adding a gallon or two.