743, a new leak

[billrbg]

This one is in the hose that is a return line from the Control Valve to the Port block. The end at the Port block should be OK to remove, but I can't even see the end down at the bottom of the Control valve. Any hints? It looks like I will have to remove several other hoses just to get down to that lower fitting; similar to when I had to change spool seals in the Control Valve. Please say it ain't so, that there is some way to get in there without pulling out a lot of other stuff...

 

[Tazza]

You have no choice but to remove parts to get to it. It is a nightmare hose to do.
Members have cut down spanners to get in there, not sure how but they got it done.
If you work out an easy way, do share it.

 

[billrbg]

You have no choice but to remove parts to get to it. It is a nightmare hose to do.
Members have cut down spanners to get in there, not sure how but they got it done.
If you work out an easy way, do share it.

I'll post how I did it, it looks like an ugly job!

 

[billrbg]

I'll post how I did it, it looks like an ugly job!

It's fixed, and was indeed a bitch! I would like to post on what I had to do, with a couple of pictures, but don't know how to add attachments here. Since the text will be fairly long-winded, I would like to write that "off-line" so as to not suddenly lose it while typing, and so that it can have proper paragraph formatting.

 

[Tazza]

It's fixed, and was indeed a bitch! I would like to post on what I had to do, with a couple of pictures, but don't know how to add attachments here. Since the text will be fairly long-winded, I would like to write that "off-line" so as to not suddenly lose it while typing, and so that it can have proper paragraph formatting.

You need to host the files on a website like photobucket. Open the file on the website, right click copy, then right click paste to the post.
Your best bet is to copy the message before posting just in case something goes wrong. From time to time errors happen then you loose the lot....
Good luck with the write up, i'm interested in how you did it.

 

[billrbg]

You need to host the files on a website like photobucket. Open the file on the website, right click copy, then right click paste to the post.
Your best bet is to copy the message before posting just in case something goes wrong. From time to time errors happen then you loose the lot....
Good luck with the write up, i'm interested in how you did it.

How about the paragraph formatting? It's going to be tough to read without that. When I first joined this forum I asked about that, and was told there was a setting in my user-profile I needed to change. However, when I tried that a worse problem popped-up. Want to try guiding me through that again?

 

[billrbg]

How about the paragraph formatting? It's going to be tough to read without that. When I first joined this forum I asked about that, and was told there was a setting in my user-profile I needed to change. However, when I tried that a worse problem popped-up. Want to try guiding me through that again?

Here is what I went through replacing the hose from the Control Valve return port and the tee on the Port Block. When I reference "right", "left", "front", or "rear" I mean directions as they would be sitting in the seat during normal operation; the bucket is in "front", and the engine in the "rear". This will usually be opposite of how you view the parts when working down in that area, but that can depend on how you prefer to contort yourself to get in there, so I feel using the "normal" orientations is appropriate. Okay, here goes... 1) Forget about reaching anything other than dropped tools from the rear, the engine compartment. 2) I removed the hose from the vane-pump outlet to the Control Valve pressure port completely. I disconnected the hose from the reservoir to the Port Block, at the Port Block end, and tied it back out of the way. I removed the hard-line from the top of the Port Block tee (line goes to oil cooler) and tied it over to the right side of the 743; then removed the tee completely. I also disconnected the front hose on the right side of the hydrostatic pump, at the pump, and tied it out of the way. Lastly, I removed the little link from the bucket-lift "bell-crank" to the top spool on the Control Valve, and disconnected the front-to-rear rod from the lift pedal. 3) The lower fitting on that hose to be replaced is buried behind the A4 port on the Control Valve. I could get no wrench in there with the hose intact. I had to cut the hose off, right in front of its lower fitting, so that I could use a 1" deep-socket on the fitting. Trouble is... there is so little clearance for the fitting, both top (A4 port fitting) and bottom (floorpan), that the socket had to be ground off on one side so as to be kind of a "deep thin-wall crow-foot" wrench. That's one of the pictures I would like to post, what I had to do to get that wrench in there. 4) Obviously, that special wrench was going to do no good putting a new hose back in. So I made a special extender fitting, a JIC female-to-male about 2.5" long, that brought that return port fitting out from under the Control Valve. I installed the adapter with a standard socket wrench, then could get to the lower fitting on the new hose with a crow-foot. There is still so little room down there that I had to tighten the Control Valve fitting a bit so that the new adapter is smack against the A4 fitting, otherwise the hose wouldn't fit on the new adapter. That port fitting and adapter point slightly down and the hose nut was too close to the floorpan once it was moved out to where it could be accessed. I made the adapter from a one-piece JIC cap welded to a JIC bulkhead union that had been shortened a bit on the long end. A cap and a tube-to-pipe connector would probably be better, just about the right length without having to cut. The fittings I used were plated and kept out-gassing as I TIG-welded, I kept getting pin-holes that leaked when I leak-tested. Stick-welding worked better, sealed all pretty quickly. I would have liked to make a one-piece adapter from a piece of bar, but too much machining for what it was worth. I would have liked it even better if Bobcat had installed such an adapter originally! Again, pictures of the extension fitting, by itself and installed, are available. 5) Since the hose lower fitting was now that 2.5" more forward, closer to the Port Block tee, it looked to me like the hose would be even more difficult to bend and install than stock. So, I had the new hose made longer, with a 45-degree fitting for the upper end, and connected to the tee kind of from the front-right of the tee rather than straight up from below. The hose is 18" front fitting seat-to-seat. 6) The simple version of this story? Cut the old hose to use a socket on the lower end, make and extension to get a new hose back in.

 

[billrbg]

Here is what I went through replacing the hose from the Control Valve return port and the tee on the Port Block. When I reference "right", "left", "front", or "rear" I mean directions as they would be sitting in the seat during normal operation; the bucket is in "front", and the engine in the "rear". This will usually be opposite of how you view the parts when working down in that area, but that can depend on how you prefer to contort yourself to get in there, so I feel using the "normal" orientations is appropriate. Okay, here goes... 1) Forget about reaching anything other than dropped tools from the rear, the engine compartment. 2) I removed the hose from the vane-pump outlet to the Control Valve pressure port completely. I disconnected the hose from the reservoir to the Port Block, at the Port Block end, and tied it back out of the way. I removed the hard-line from the top of the Port Block tee (line goes to oil cooler) and tied it over to the right side of the 743; then removed the tee completely. I also disconnected the front hose on the right side of the hydrostatic pump, at the pump, and tied it out of the way. Lastly, I removed the little link from the bucket-lift "bell-crank" to the top spool on the Control Valve, and disconnected the front-to-rear rod from the lift pedal. 3) The lower fitting on that hose to be replaced is buried behind the A4 port on the Control Valve. I could get no wrench in there with the hose intact. I had to cut the hose off, right in front of its lower fitting, so that I could use a 1" deep-socket on the fitting. Trouble is... there is so little clearance for the fitting, both top (A4 port fitting) and bottom (floorpan), that the socket had to be ground off on one side so as to be kind of a "deep thin-wall crow-foot" wrench. That's one of the pictures I would like to post, what I had to do to get that wrench in there. 4) Obviously, that special wrench was going to do no good putting a new hose back in. So I made a special extender fitting, a JIC female-to-male about 2.5" long, that brought that return port fitting out from under the Control Valve. I installed the adapter with a standard socket wrench, then could get to the lower fitting on the new hose with a crow-foot. There is still so little room down there that I had to tighten the Control Valve fitting a bit so that the new adapter is smack against the A4 fitting, otherwise the hose wouldn't fit on the new adapter. That port fitting and adapter point slightly down and the hose nut was too close to the floorpan once it was moved out to where it could be accessed. I made the adapter from a one-piece JIC cap welded to a JIC bulkhead union that had been shortened a bit on the long end. A cap and a tube-to-pipe connector would probably be better, just about the right length without having to cut. The fittings I used were plated and kept out-gassing as I TIG-welded, I kept getting pin-holes that leaked when I leak-tested. Stick-welding worked better, sealed all pretty quickly. I would have liked to make a one-piece adapter from a piece of bar, but too much machining for what it was worth. I would have liked it even better if Bobcat had installed such an adapter originally! Again, pictures of the extension fitting, by itself and installed, are available. 5) Since the hose lower fitting was now that 2.5" more forward, closer to the Port Block tee, it looked to me like the hose would be even more difficult to bend and install than stock. So, I had the new hose made longer, with a 45-degree fitting for the upper end, and connected to the tee kind of from the front-right of the tee rather than straight up from below. The hose is 18" front fitting seat-to-seat. 6) The simple version of this story? Cut the old hose to use a socket on the lower end, make and extension to get a new hose back in.

I forgot one important point about that "extension" for the fitting where the lower end of the hose attaches. The hex on a bulkhead union is too big (1.125") to fit, it is that close to the floorpan. A tube-to-MPT connector has a 15/16" hex, another reason that would be the better one to use if. (Icut the flats on the union down to 1", and that fit)

 

[Tazza]

I forgot one important point about that "extension" for the fitting where the lower end of the hose attaches. The hex on a bulkhead union is too big (1.125") to fit, it is that close to the floorpan. A tube-to-MPT connector has a 15/16" hex, another reason that would be the better one to use if. (Icut the flats on the union down to 1", and that fit)

Nice job, never thought about cutting the fitting off the hose to get a socket over it. How on earth did you get in there to cut the hose off? i bet there was a lot of curse words used......
An adaptor is the smart way of doing it, Bobcat figured it will outlast warranty, so why bother making it easier to replace?

 

[billrbg]

Nice job, never thought about cutting the fitting off the hose to get a socket over it. How on earth did you get in there to cut the hose off? i bet there was a lot of curse words used......
An adaptor is the smart way of doing it, Bobcat figured it will outlast warranty, so why bother making it easier to replace?

Actually, cutting the hose was one of the easiest and quickest tasks... once I figured out how to do it! My first thought was to use a "cable saw" with abrasive grit on the cable, but I was unable to locate such a beast. So, I tied using something similar, a fine-wire saw with teeth on it, often called "pocket saws" or "survival saws". I tried two, both not only dulled quickly but broke in a matter of minutes due to flexing 180 degrees around that hose. So, I resorted to a die-grinder with a rotary rasp in it. The rasp didn't cut the wires in the hose, just grabbed them and ripped them apart. It took only a minute or so to cut through the hose. Once all those other hoses are out of the way, there was ample room to poke my big electric die-grinder down there; its length was actually an advantage. I wish I could post the pix so you could see what I had to do to that socket wrench!

 

[Tazza]

Actually, cutting the hose was one of the easiest and quickest tasks... once I figured out how to do it! My first thought was to use a "cable saw" with abrasive grit on the cable, but I was unable to locate such a beast. So, I tied using something similar, a fine-wire saw with teeth on it, often called "pocket saws" or "survival saws". I tried two, both not only dulled quickly but broke in a matter of minutes due to flexing 180 degrees around that hose. So, I resorted to a die-grinder with a rotary rasp in it. The rasp didn't cut the wires in the hose, just grabbed them and ripped them apart. It took only a minute or so to cut through the hose. Once all those other hoses are out of the way, there was ample room to poke my big electric die-grinder down there; its length was actually an advantage. I wish I could post the pix so you could see what I had to do to that socket wrench!

To fix your paragraphs, you should be able to go into your profile and click the box that says use html editor, free text box.
If you post with internet explorer, the posts will format correctly.
The wires in the hose are high tensile, i'm inpressed it cut so easily.
If you look up my profile, can you send me a picture of the socket?