bobcat 463

[Tazza]

Well, an update. I spent the day making sure the fuel lines were clear and new fuel filter and good glow plugs. Then, i noticed on the page the Old Machinist had uploaded for me that i need a special socket to remove the injectors and i tried a wrench but i was worried that something would break because i put quite a bit of pressure on them and they wouldnt crack loose, and of course the bobcat dealer closes early and i couldnt get a socket from them. Then i got a compression tester and tried to find an adapter that would screw into the glow plug holes and failed miserably on that. So anyway, i will have to try next week to get the injectors off and test them and also see if the bobcat dealer has an adapter that i can screw into the glow plug hole or the injector hole to test compression. Thanks all for the help and i will update next week to let you know how i do on the compression test and getting the injectors cleaned. If you have any thoughts for me on either of these feel free to let me know. Thanks again

You don't need a special socket as such, you just need a deep one. I don't know what size it is though sorry but I'm pretty sure its metric being Japanese.
The best adapter for the glow plug hole is an old glow plug! Drill the tip and guts out and weld it up to an adapter. This does assume you have a spare plug to wreck....
I had a look at my dads 453 yesterday, i thought you couldn't access the injector pump but when you lift the cab its rite there. If you can remove the injectors and hook a tube line to a delivery valve and hook up an injector on the end, spin the engine over and check the spray. I don't know how you will go as i have done it on V1702's and V2203's with heaps of room out the back. Your goal is a thin cone with no droplets forming on the tip of the injector.
His machine needs 3 axles doing as the bearings are dead. I'm really not looking forward to doing this! I have enough projects of my own on the go.
I'm sure you will get your beast up and running again!

 

[OldMachinist]

You don't need a special socket as such, you just need a deep one. I don't know what size it is though sorry but I'm pretty sure its metric being Japanese.
The best adapter for the glow plug hole is an old glow plug! Drill the tip and guts out and weld it up to an adapter. This does assume you have a spare plug to wreck....
I had a look at my dads 453 yesterday, i thought you couldn't access the injector pump but when you lift the cab its rite there. If you can remove the injectors and hook a tube line to a delivery valve and hook up an injector on the end, spin the engine over and check the spray. I don't know how you will go as i have done it on V1702's and V2203's with heaps of room out the back. Your goal is a thin cone with no droplets forming on the tip of the injector.
His machine needs 3 axles doing as the bearings are dead. I'm really not looking forward to doing this! I have enough projects of my own on the go.
I'm sure you will get your beast up and running again!

The Kubota D722 engine in the 453 is used in many other applications so you're not limited to a Bobcat dealer for parts and service. They are used in Kubota tractors, several different lawn mowers, generators and boats so any place that sells and services Kubota powered equipment should be able to help. And any diesel repair shop should be able to clean and check the cracking pressure on the injectors.

 

[scuba623]

The Kubota D722 engine in the 453 is used in many other applications so you're not limited to a Bobcat dealer for parts and service. They are used in Kubota tractors, several different lawn mowers, generators and boats so any place that sells and services Kubota powered equipment should be able to help. And any diesel repair shop should be able to clean and check the cracking pressure on the injectors.

Daily update. Today i put in a new fuel pump that i got from the dealer...that was a good time, two nuts and 1 hour later and had them swapped. The fuel pump is put in the hardest spot to get at and the nuts can only be loosened with an open end wrench. Anyway, i got that done and then put in a new relay for the glow plugs and when i hold the rocker i get a click so i think its working now. BUT...still doesnt start. Bobcat dealer does not carry the thread on adapter for a compression tester but they said to go to Carquest and they can order one...3-5 business days...:< so i got that to do but i still cant get the bobcat to start. I tried some starter fluid and i had the cab up and i was standing up in the cab space and i shot a spray of it into the intake and then FWOOM a huge flame shot out of the intake OOPS...not sure why it did that but prolly ignited too soon from the glow plugs or something. Anyway, i think i got the problem pretty well surrounded now but still dont have the answer so hopefully i can narrow it down to something and get this thing started. Any ideas are really appreciated. Thanks for all the help

 

[Tazza]

Daily update. Today i put in a new fuel pump that i got from the dealer...that was a good time, two nuts and 1 hour later and had them swapped. The fuel pump is put in the hardest spot to get at and the nuts can only be loosened with an open end wrench. Anyway, i got that done and then put in a new relay for the glow plugs and when i hold the rocker i get a click so i think its working now. BUT...still doesnt start. Bobcat dealer does not carry the thread on adapter for a compression tester but they said to go to Carquest and they can order one...3-5 business days...:< so i got that to do but i still cant get the bobcat to start. I tried some starter fluid and i had the cab up and i was standing up in the cab space and i shot a spray of it into the intake and then FWOOM a huge flame shot out of the intake OOPS...not sure why it did that but prolly ignited too soon from the glow plugs or something. Anyway, i think i got the problem pretty well surrounded now but still dont have the answer so hopefully i can narrow it down to something and get this thing started. Any ideas are really appreciated. Thanks for all the help

Hopefully your glow plugs were not on when you gave it a snort of starting juice, it can set it off and do what you describe. The can should tall you never glow a diesel when using ether.
Have you checked the injectors at all?

 

[scuba623]

Hopefully your glow plugs were not on when you gave it a snort of starting juice, it can set it off and do what you describe. The can should tall you never glow a diesel when using ether.
Have you checked the injectors at all?

I dont think they were glowing because i wasnt holding the rocker switch. No on the injectors i am going to tackle that problem tomorrow and see what i can do and then i will let you know what i find.

 

[scuba623]

I dont think they were glowing because i wasnt holding the rocker switch. No on the injectors i am going to tackle that problem tomorrow and see what i can do and then i will let you know what i find.

Tazza, i got a question for you. I have a turn valve where the line comes in from my lift pump that feeds the injector pump. there is also a small line that goes from there up to my injectors that feed through to the banjo fittings. Is this valve supposed to be turned all the way in out out or somewhere in between? What is it for?

 

[Tazza]

Tazza, i got a question for you. I have a turn valve where the line comes in from my lift pump that feeds the injector pump. there is also a small line that goes from there up to my injectors that feed through to the banjo fittings. Is this valve supposed to be turned all the way in out out or somewhere in between? What is it for?

It is to be turned in, this is used to bleed the fuel line.
To bleed it you open the valve (anti-clockwise) then squeeze the primer bulb till it feels firm and you can't hear bubbles. Close the valve and you are good to go. If you trace the line from the valve you will notice it goes to the injector tap off lines then back to the fuel tank. This way you don't make a big mess when you need to prime the system.
If the valve is not fully closed the lift pump pressure is too low and the engine will not operate correctly. For me the machine will start but then stop.

 

[scuba623]

It is to be turned in, this is used to bleed the fuel line.
To bleed it you open the valve (anti-clockwise) then squeeze the primer bulb till it feels firm and you can't hear bubbles. Close the valve and you are good to go. If you trace the line from the valve you will notice it goes to the injector tap off lines then back to the fuel tank. This way you don't make a big mess when you need to prime the system.
If the valve is not fully closed the lift pump pressure is too low and the engine will not operate correctly. For me the machine will start but then stop.

Ok, thx. I took my fuel lines off and was able to blow air threw them and then with them off i turned over the motor and i got fuel to shoot up to the cab so i know im getting good pressure now with my new pump but i cant seem to break the injectors loose, them things are ON THERE. Anyway, now with my new glow plug relay i can hold the rocker switch for the glow plugs while im cranking it over and i get quite abit of black smoke and it seems like it wants to start but i keep wearing the battery down instead. It seems like it is getting good compression now too but i still am waiting for my adapter to check the compression with...few more days on that. Tazza, if im getting black smoke shouldnt that mean my injectors are good because thats excess fuel or can bad injectors still do that?

 

[Tazza]

Ok, thx. I took my fuel lines off and was able to blow air threw them and then with them off i turned over the motor and i got fuel to shoot up to the cab so i know im getting good pressure now with my new pump but i cant seem to break the injectors loose, them things are ON THERE. Anyway, now with my new glow plug relay i can hold the rocker switch for the glow plugs while im cranking it over and i get quite abit of black smoke and it seems like it wants to start but i keep wearing the battery down instead. It seems like it is getting good compression now too but i still am waiting for my adapter to check the compression with...few more days on that. Tazza, if im getting black smoke shouldnt that mean my injectors are good because thats excess fuel or can bad injectors still do that?

No, black smoke could be from fuel dribbling onto the hot glow plug. If you don't have a fine spray all the fuel will do is burn. You essentially want it to have a fine mist with heaps of air and compression to make it detonate.
Think of it this way, you can get fuel and pour it out on the ground and light it up, it will burn. But think of something like a fuel/air bomb, it sprays out the same fuel (ok, so its jet fuel but you get the idea), it mixes in the air and then is detonated causing a MASSIVE explosion. This is what you are looking for, a fine fuel spray plus air then heat from compression will cause it to explode.
What exactly is the problem with removing the injectors? is it hard removing the nuts that hold tap off line? or the injectors them self? You should be able to get a deep socket and with the tap off lines removed just un-do them. I can measure an injector body tonight if you need the size? if you send me an e-mail, its listed in my profile to remind me if you want it.
You have more or less eliminated everything else, it has to be compression or injectors.

 

[scuba623]

No, black smoke could be from fuel dribbling onto the hot glow plug. If you don't have a fine spray all the fuel will do is burn. You essentially want it to have a fine mist with heaps of air and compression to make it detonate.
Think of it this way, you can get fuel and pour it out on the ground and light it up, it will burn. But think of something like a fuel/air bomb, it sprays out the same fuel (ok, so its jet fuel but you get the idea), it mixes in the air and then is detonated causing a MASSIVE explosion. This is what you are looking for, a fine fuel spray plus air then heat from compression will cause it to explode.
What exactly is the problem with removing the injectors? is it hard removing the nuts that hold tap off line? or the injectors them self? You should be able to get a deep socket and with the tap off lines removed just un-do them. I can measure an injector body tonight if you need the size? if you send me an e-mail, its listed in my profile to remind me if you want it.
You have more or less eliminated everything else, it has to be compression or injectors.

An update. I took out all three injectors and followed Tazza and Old Mechanics instructions. The injectors were all in horrible shape. Black carbon build up extremely bad. I cleaned and scrubbed every piece with a tooth brush and WD40 and install the injectors back into the bobcat. I am now waiting for the battery to charge back up to try and start it and see how it works. Thanks for all the help. Much appreciated.

 

[scuba623]

An update. I took out all three injectors and followed Tazza and Old Mechanics instructions. The injectors were all in horrible shape. Black carbon build up extremely bad. I cleaned and scrubbed every piece with a tooth brush and WD40 and install the injectors back into the bobcat. I am now waiting for the battery to charge back up to try and start it and see how it works. Thanks for all the help. Much appreciated.

Well, i tried the intial start and now im getting white smoke. It doesnt sound much different then it did before but just getting the white smoke now. Any ideas why??

 

[scuba623]

Well, i tried the intial start and now im getting white smoke. It doesnt sound much different then it did before but just getting the white smoke now. Any ideas why??

one last thing. i took off the plate where my two knobs are in the front of the cab and i found a little red button. Anyone know what this is for?? I dont know if it pushes or what it does but i tried to push it and nothing happens. The only time i can see it is when this plate is off.

 

[OldMachinist]

one last thing. i took off the plate where my two knobs are in the front of the cab and i found a little red button. Anyone know what this is for?? I dont know if it pushes or what it does but i tried to push it and nothing happens. The only time i can see it is when this plate is off.

You didn't say if you ever got some compression readings. There is a crankcase breather tube that comes down off the valve cover put your finger over the end of the tube and have someone crank it over. You should feel a little blowby pressure there but if theres a lot it could be that the piston rings are stuck from sitting so long and the compression is real low.

 

[scuba623]

You didn't say if you ever got some compression readings. There is a crankcase breather tube that comes down off the valve cover put your finger over the end of the tube and have someone crank it over. You should feel a little blowby pressure there but if theres a lot it could be that the piston rings are stuck from sitting so long and the compression is real low.

about the compression readings...the place i tried to order the part from ordered the wrong one so i went in with my glow plug and now gotta wait for another week and see if the new one works.AAARG...still having fun tinkering tho. Its kinda wierd cause i went in to the bobcat dealer here and when i was talking to one of the guys he told me to see if my fuel solenoid was working because according to my serial number i have one. Well i came home and tried to find one but i dont think i do becasue it wasnt where he said it was. If i have a pull cable going to the fuel injectors does that mean i dont have a fuel solenoid?

 

[scuba623]

about the compression readings...the place i tried to order the part from ordered the wrong one so i went in with my glow plug and now gotta wait for another week and see if the new one works.AAARG...still having fun tinkering tho. Its kinda wierd cause i went in to the bobcat dealer here and when i was talking to one of the guys he told me to see if my fuel solenoid was working because according to my serial number i have one. Well i came home and tried to find one but i dont think i do becasue it wasnt where he said it was. If i have a pull cable going to the fuel injectors does that mean i dont have a fuel solenoid?

Ok, i cranked the engine over and the breather tube that comes down the back of the engine does have some pressure. If i hold the end with thumb for a couple seconds there is a little bit of pressure build up. It also has a little bit of white smoke coming out as well. Lastly, everytime i take a glow plug out it has black oil on the tip. I clean it off, put it back in and when i crank it over for like 20 seconds and pull the glow plug it has oil on it again. Any ideas?? Also, if it does have bad compression does that mean i should yank the engine and get new rings or what do i have to do to fix that?

 

[OldMachinist]

Ok, i cranked the engine over and the breather tube that comes down the back of the engine does have some pressure. If i hold the end with thumb for a couple seconds there is a little bit of pressure build up. It also has a little bit of white smoke coming out as well. Lastly, everytime i take a glow plug out it has black oil on the tip. I clean it off, put it back in and when i crank it over for like 20 seconds and pull the glow plug it has oil on it again. Any ideas?? Also, if it does have bad compression does that mean i should yank the engine and get new rings or what do i have to do to fix that?

Doesn't sound like alot of blowby coming out the tube, but the smoke doesn't sound good on a non running engine. If it was running and had a little smoke no big deal. The oil on the glow plug is oil not diesel? And do you know how many hours are on the machine?

 

[OldMachinist]

Doesn't sound like alot of blowby coming out the tube, but the smoke doesn't sound good on a non running engine. If it was running and had a little smoke no big deal. The oil on the glow plug is oil not diesel? And do you know how many hours are on the machine?

I just remembered to look at the parts book to see what engine you had. By the serial number you posted its a D750 and it doesn't have a shut off solenoid just the pull cable. Unless the engine has been replaced. The D750 is easier to repair a compression problem due to wear because it has cylinder sleeves and the D722 doen't so it has to be bored out to repair.

 

[scuba623]

I just remembered to look at the parts book to see what engine you had. By the serial number you posted its a D750 and it doesn't have a shut off solenoid just the pull cable. Unless the engine has been replaced. The D750 is easier to repair a compression problem due to wear because it has cylinder sleeves and the D722 doen't so it has to be bored out to repair.

Yeh i have the D750 kubota in it. So if it has bad compression i got to pull the engine and get new sleeves and new piston rings and that should fix it or is there more to it then that?? And are these parts best to get from the dealer or can a engine shop make/get them??

 

[OldMachinist]

Yeh i have the D750 kubota in it. So if it has bad compression i got to pull the engine and get new sleeves and new piston rings and that should fix it or is there more to it then that?? And are these parts best to get from the dealer or can a engine shop make/get them??

I would think that a Kubota tractor dealer or any diesel repair shop could get the parts needed. But it still depends on why the compression is low. If the the rings are just stuck in the grooves you might get away with just a set of rings, deglaze the cylinders and the gaskets to put it back together. If it has a lot of hours on it a full rebuild might be needed. You would have to price out the parts and valve job to see if its justifiable or just buy a rebuilt engine. The only place I've found online that says they have rebuild kits for Kubota is here.
http://www.foleyengines.com/EngineProducts/EngineOverhaulPartsKits.aspx

 

[OldMachinist]

I would think that a Kubota tractor dealer or any diesel repair shop could get the parts needed. But it still depends on why the compression is low. If the the rings are just stuck in the grooves you might get away with just a set of rings, deglaze the cylinders and the gaskets to put it back together. If it has a lot of hours on it a full rebuild might be needed. You would have to price out the parts and valve job to see if its justifiable or just buy a rebuilt engine. The only place I've found online that says they have rebuild kits for Kubota is here.
http://www.foleyengines.com/EngineProducts/EngineOverhaulPartsKits.aspx

Found another parts and engine supplier.
http://www.engreb.com/index.php