Bobcat 630 Reclamation

[peebeeaitch]

I bought a 630 for a project and this is the chronology of its reclamation.
22 Dec 2012
Cleaning (a colleague lent me a "hotsy"):

Moving the machine from where the towing company left it - always have a good friend with a car "with a big engine and really sh*tty gas mileage" (RoboCop) to help. Also, two pallet jacks can lift 3 Bobcat 630's (according to the manufacturer of the pallet jacks and the Bobcat):

Hillbilly owner (me). Strong car (belonging to good friend):

And finally:

23 Dec 2012
Spent the morning opening various covers. Checked the distributor for water and found plenty from the "hotsy". I was told when I bought the machine that it had worked but the left stick stopped sending the force to the left wheels. The force was working on the right though. Obviously, starting the engine was the key to determining if the force could be moved to the left. Armed with a cheap set of wrenches and a can of QuickStart I managed to get a burp out of the engine. The fuel tank has been replaced by a Jerry Can with custom brazed connection at the bottom leading to a primable fuel filter. No fuel out of the fuel filter outlet and I rushed off to get a funnel to fill the tank to be able to prime the bowl. A bit of propane torch on the funnel and I managed to bend the end to fit in the "tank". I also was reminded that plastic that is bendable and collapses tends to hurt fingers that are introduced to the opening to "unbend" kink. Filled the tank, primed the pump and introduced the starting fluid and SHE FIRED UP!!!

Note to self: When the rest of the family is watching the festivities from a SEPARATE room, looking through a glass pane in the door, furious gesticulations and pointing are generally not signs of awe and wonderment at one's ability in getting dead mechanical machinery alive, they are more likely signs of catastrophic failure of hydraulic lines one cannot see:

(the broken line is, quite predicatably, hidden below the hinge pin on the right support arm).
I shut the engine off. After thinking about it for a while (and cleaning the mess), I decided that the oil that had leaked was probably in need of replacing anyway, and there was hopefully enough left to lift the arms so that I could get to the hose connector to replace the lines:

This is the tilt cylinder with a seriously frayed line. I can only imagine what the other one leading into the arm looks like.
Also, I noticed earlier this evening that the right support arm is kinked (see photo above). This is bad news (and explains why the ROPS on the right is closer to the arm than on the left). I hope I can get the back hinge pin out to replace it - the previous owners did not believe in grease, hence the sloppiness in all hydraulic motions.
To do:
* buy tools to remove lines
* replace lines
* get engine to fire without Quick Start
* replace starter solenoid
* dump snow

 

[Zorack]

Great post,and keep posting pictures of your project

 

[ancomcabs]

Great post,and keep posting pictures of your project

peebeeaitch-I just fixed up and sold a 630 myself and have a pdf service manual if you are interested, send me an e-mail to: ancomcabs at gmail dot com and I will send you a copy

 

[peebeeaitch]

peebeeaitch-I just fixed up and sold a 630 myself and have a pdf service manual if you are interested, send me an e-mail to: ancomcabs at gmail dot com and I will send you a copy

Thanks for the replies.
ancomcabs - I have read your restoration post (630 Restore). That is why I was very careful not to call this a "restoration" as there is no way in hell my little project is going to look anywhere near as good as yours once complete. I have sent a mail requesting the manual - thanks.
I need a weekend project (to keep the hands busy), my colleagues tell me horror stories of the snow and country living, I see a Bobcat next to the side of the road on some farmer's field and two birds are killed with some dollars!

 

[Zorack]

Thanks for the replies.
ancomcabs - I have read your restoration post (630 Restore). That is why I was very careful not to call this a "restoration" as there is no way in hell my little project is going to look anywhere near as good as yours once complete. I have sent a mail requesting the manual - thanks.
I need a weekend project (to keep the hands busy), my colleagues tell me horror stories of the snow and country living, I see a Bobcat next to the side of the road on some farmer's field and two birds are killed with some dollars!

Lucky dude,sometimes good fortunes come at an opportune time

 

[HanSolo]

The bent arm may have been caused by too heavy a load. I noted that machine has a high capacity bucket which is designed for light weight materials (grain, feed, etc). When you get it up a running, you might want to look into getting a general purpose bucket if your going to be digging earth, spreading gravel or topsoil.

 

[peebeeaitch]

The bent arm may have been caused by too heavy a load. I noted that machine has a high capacity bucket which is designed for light weight materials (grain, feed, etc). When you get it up a running, you might want to look into getting a general purpose bucket if your going to be digging earth, spreading gravel or topsoil.

Ha, that makes sense. The chap I bought it from used it to load mulch. He in turn bought it from a "logging" company. Having watched some so-called reality shows about loggers, I was thinking that they may have used it for something other than for what it was originally designed - like side line prospecting for gold (another reality series).
When I get it running I will definately look at a specification bucket. As it is, the Bobtach is really sloppy so I'll first want to get that tightened up anyway.
Should I worry about the arm? I can see the U section at the back where the pin support is located is not so much a U anymore, so the arm buckled as opposed to bending the pin. I am not worried about the pin, but the right lift cylinder is now not pushing in a plane parallel to the edge of the machine, it is pushing a bit to the left. I am concerned that as I go through the machine fixing slop, I am going to get to the point where the slop which prevented side-loading on the cylinder rod end will be eliminated, causing side loading and eventual cylinder failure (my kids will probably also again be witnesses and be pointing excitedly).

 

[mahans7]

Ha, that makes sense. The chap I bought it from used it to load mulch. He in turn bought it from a "logging" company. Having watched some so-called reality shows about loggers, I was thinking that they may have used it for something other than for what it was originally designed - like side line prospecting for gold (another reality series).
When I get it running I will definately look at a specification bucket. As it is, the Bobtach is really sloppy so I'll first want to get that tightened up anyway.
Should I worry about the arm? I can see the U section at the back where the pin support is located is not so much a U anymore, so the arm buckled as opposed to bending the pin. I am not worried about the pin, but the right lift cylinder is now not pushing in a plane parallel to the edge of the machine, it is pushing a bit to the left. I am concerned that as I go through the machine fixing slop, I am going to get to the point where the slop which prevented side-loading on the cylinder rod end will be eliminated, causing side loading and eventual cylinder failure (my kids will probably also again be witnesses and be pointing excitedly).

Hey PB, I agree with you and would be worried about the bent sidearm especially if its not pushing in the correct plane. Right lift cylinder failure is likely to follow.

 

[peebeeaitch]

Hey PB, I agree with you and would be worried about the bent sidearm especially if its not pushing in the correct plane. Right lift cylinder failure is likely to follow.

26 Dec 2012
Removed the lines on the tilt circuit - all 4 of them (see this post: Hydraulic Hoses - Check or Replace?).
Off I went to the local agricultural repair place that had been recommended to me. I think when they saw me, they realised that the opportunity existed to make up the sales not only for December 2012, but for the entire year of 2012. The helpful chap almost ripped the lines out of my hands in his eagerness to make replacements. 20 minutes later, however, I had 4 new lines, with abrasion sleeving.

I am very happy I decided to replace all 4 lines. When I was cleaning the hoses to take to the shop, I coiled them up. There was a crackling sound. Not a good crackling sound. It sounded like there was scale or something in the pipes that was being cracked as I tightened the radius. I realise that this is probably not the case and it is more likely the rubber crackling, but in either case the one means little pieces of something in the oil or no oil at all in the other.
Replaced the lines and fired up the machine. I discovered that the solenoid is, in fact, working, but not receiving a signal from the keyswitch. I have not delved into the electrical stuff yet as this is all mostly operational and I have some serious electrical plans for the machine in the future - no use wasting time running new electrical lines that will be replaced anyway. Also, I am fairly confident that the machine will start without Quickstart (fingers crossed).
Dropped the bucket (after bending some of the ROPS bracing - more to come) and nestled it up against the frame - after almost taking out the ceiling, two pallet jacks (mentioned in a previous post), a cat and an old refrigerator. First time in a Bobcat, in a garage, in an adoptive country, in the middle of the coldest I have ever experienced in my entire existence is perhaps not the ideal self-tuition environment.

(The two lines leading to the tilt cylinder with the abrasion sleeving visible).
After I calmed the beast down, I switched off and went to go and clear the tools away from the back of the machine so that I could triumphantly exit the garage on Bobcat power alone.
Crushing defeat: dripping, splattered oil over all the tools. A new leak.
This time on the arm lift cylinders. When I was supporting the arms in order to replacer the previous lines, I ran some round bar under the lift arms and used some of the square hole separators in the ROPS to hold the bar. After firing up the machine this time, I pressed ARM DOWN pedal operation and the machine dutifully bent the separator, and probably burst the hose (no photos of this one, it is a little embarrasing).

The burst hose is on the right - I think it has let go at the swaged connection). Right, so now I need some help. There is no way on earth that the wrenches (this time, the expensive big ones) are going to get into that little space to remove the lines from the base of the lift cylinder. I can only assume that the way to get to them is to lift the arms as high as they will go? If so, I need to go in to work tomorrow and fabricate some form of cylinder lift stop, so what is the extension length of the cylinder?
Thanks in advance.
PBH

 

[ancomcabs]

26 Dec 2012
Removed the lines on the tilt circuit - all 4 of them (see this post: Hydraulic Hoses - Check or Replace?).
Off I went to the local agricultural repair place that had been recommended to me. I think when they saw me, they realised that the opportunity existed to make up the sales not only for December 2012, but for the entire year of 2012. The helpful chap almost ripped the lines out of my hands in his eagerness to make replacements. 20 minutes later, however, I had 4 new lines, with abrasion sleeving.

I am very happy I decided to replace all 4 lines. When I was cleaning the hoses to take to the shop, I coiled them up. There was a crackling sound. Not a good crackling sound. It sounded like there was scale or something in the pipes that was being cracked as I tightened the radius. I realise that this is probably not the case and it is more likely the rubber crackling, but in either case the one means little pieces of something in the oil or no oil at all in the other.
Replaced the lines and fired up the machine. I discovered that the solenoid is, in fact, working, but not receiving a signal from the keyswitch. I have not delved into the electrical stuff yet as this is all mostly operational and I have some serious electrical plans for the machine in the future - no use wasting time running new electrical lines that will be replaced anyway. Also, I am fairly confident that the machine will start without Quickstart (fingers crossed).
Dropped the bucket (after bending some of the ROPS bracing - more to come) and nestled it up against the frame - after almost taking out the ceiling, two pallet jacks (mentioned in a previous post), a cat and an old refrigerator. First time in a Bobcat, in a garage, in an adoptive country, in the middle of the coldest I have ever experienced in my entire existence is perhaps not the ideal self-tuition environment.

(The two lines leading to the tilt cylinder with the abrasion sleeving visible).
After I calmed the beast down, I switched off and went to go and clear the tools away from the back of the machine so that I could triumphantly exit the garage on Bobcat power alone.
Crushing defeat: dripping, splattered oil over all the tools. A new leak.
This time on the arm lift cylinders. When I was supporting the arms in order to replacer the previous lines, I ran some round bar under the lift arms and used some of the square hole separators in the ROPS to hold the bar. After firing up the machine this time, I pressed ARM DOWN pedal operation and the machine dutifully bent the separator, and probably burst the hose (no photos of this one, it is a little embarrasing).

The burst hose is on the right - I think it has let go at the swaged connection). Right, so now I need some help. There is no way on earth that the wrenches (this time, the expensive big ones) are going to get into that little space to remove the lines from the base of the lift cylinder. I can only assume that the way to get to them is to lift the arms as high as they will go? If so, I need to go in to work tomorrow and fabricate some form of cylinder lift stop, so what is the extension length of the cylinder?
Thanks in advance.
PBH

You'll robably have to remove the cylinder pivot pins and remove or shift the cylinders to get to those fittings

 

[Mikefromcny]

You'll robably have to remove the cylinder pivot pins and remove or shift the cylinders to get to those fittings

A good inexpensive loader brace is a 1/4 inch thick piece of angle iron laying across the chrome rod with the loader up.

 

[SkidRoe]

A good inexpensive loader brace is a 1/4 inch thick piece of angle iron laying across the chrome rod with the loader up.

And if Murphy shows up again tomorrow, you may want to put a couple of hose clamps around that piece of angle iron to keep it from slipping. People messing with hoses on raised booms are part of the reason why new Bobcats have so many safety interlocks. Wishing you luck!!

 

[peebeeaitch]

And if Murphy shows up again tomorrow, you may want to put a couple of hose clamps around that piece of angle iron to keep it from slipping. People messing with hoses on raised booms are part of the reason why new Bobcats have so many safety interlocks. Wishing you luck!!

27 Dec 2012
Right. The saga continues.
Thanks to ancomcabs suggestion above, I lifted the bucket, supported it and started removing the rear pin. The thinking was that Murphy was probably not around and that I would be able to compress the cylinder once the machine side pin had been replaced - anyway, no matter if I also had to remove the rod side, the rear pin would also need to come out.
I bashed and hammered the thing for a while - even after slacking off the hydraulics by pressing all levers and pedals - and EVENTUALLY got the rear pin out. Murphy was, in fact, lurking and I could not for the life of me compress the cylinder. So, removed the lock pin and removed the front pin. It was quite easy to remove the entire cylinder after that. I wish I hadn't.
This is the repair workmanship that greeted me:

And, in case one thought "that doesn't look so bad", this:

(Red wire is there so that I could mark the lines and pipes. I've found tape usually comes loose and then frustration). This is going to give way sooner or later, but I know it will be when I REALLY need the machine.
Off I went to the friendly (they get more so every time I walk in their door) hydraulics repair shop and in short order had two new complete lines with abrasion resistant covers. The chap looked positively devastated when he told me that his abrasion resistant sheathing was finished and that he would only have some in the new year.

As a precaution I cleaned out the cylinder ends to inspect. I thought there would be a lot more damage, but I think this may be OK for a while. Still worried about the bent arm though:

The rear pin looks good. I tried to feel for a wear ridge or something to indicate imminent failure, but it seems OK to me:

Same with the front pin:

The cylinder was replaced and I fired her up - this time the keyswitch worked, no starting fluid, choke only!!!
Ok. Up, down, in, out - jerky. Forward, back - almost no motion. The thought was immediately oil, or the annoying little brass filter.
Opened up the middle hydraulic line and I don't think I have the brass filter anymore. Is this possible?
Bought some oil and filled it up - needed about 1/3 of the full capacity so I doubt it is an oil problem.
I am re-reading all the posts that deal with hydraulic jerkiness, lack of motion and all other symptoms. The fact that the guy that I bought it from's assessment of all other problems is more or less correct seems to indicate that the pump should be OK - it was only the left drive that he said was faulty. More tomorrow...

 

[Mikefromcny]

27 Dec 2012
Right. The saga continues.
Thanks to ancomcabs suggestion above, I lifted the bucket, supported it and started removing the rear pin. The thinking was that Murphy was probably not around and that I would be able to compress the cylinder once the machine side pin had been replaced - anyway, no matter if I also had to remove the rod side, the rear pin would also need to come out.
I bashed and hammered the thing for a while - even after slacking off the hydraulics by pressing all levers and pedals - and EVENTUALLY got the rear pin out. Murphy was, in fact, lurking and I could not for the life of me compress the cylinder. So, removed the lock pin and removed the front pin. It was quite easy to remove the entire cylinder after that. I wish I hadn't.
This is the repair workmanship that greeted me:

And, in case one thought "that doesn't look so bad", this:

(Red wire is there so that I could mark the lines and pipes. I've found tape usually comes loose and then frustration). This is going to give way sooner or later, but I know it will be when I REALLY need the machine.
Off I went to the friendly (they get more so every time I walk in their door) hydraulics repair shop and in short order had two new complete lines with abrasion resistant covers. The chap looked positively devastated when he told me that his abrasion resistant sheathing was finished and that he would only have some in the new year.

As a precaution I cleaned out the cylinder ends to inspect. I thought there would be a lot more damage, but I think this may be OK for a while. Still worried about the bent arm though:


The rear pin looks good. I tried to feel for a wear ridge or something to indicate imminent failure, but it seems OK to me:

Same with the front pin:

The cylinder was replaced and I fired her up - this time the keyswitch worked, no starting fluid, choke only!!!
Ok. Up, down, in, out - jerky. Forward, back - almost no motion. The thought was immediately oil, or the annoying little brass filter.
Opened up the middle hydraulic line and I don't think I have the brass filter anymore. Is this possible?
Bought some oil and filled it up - needed about 1/3 of the full capacity so I doubt it is an oil problem.
I am re-reading all the posts that deal with hydraulic jerkiness, lack of motion and all other symptoms. The fact that the guy that I bought it from's assessment of all other problems is more or less correct seems to indicate that the pump should be OK - it was only the left drive that he said was faulty. More tomorrow...

Nice write up. I personally would rather be in the garage then inside with family, watching tv or what not. I've never had a machine that had the brass filter thing, but it seems like all the 630s should be old enough to have it. I'm sure someone else will chime in.

 

[peebeeaitch]

Nice write up. I personally would rather be in the garage then inside with family, watching tv or what not. I've never had a machine that had the brass filter thing, but it seems like all the 630s should be old enough to have it. I'm sure someone else will chime in.

Thanks Mike. I hope the pictures help someone else like me that was new to Bobcats and didn't have the faintest idea what was being spoken about on initial read. I would have prefered if I did not have to take them though.
Been reading and just realised that I have two, hopefully independant problems.
Jerkiness in tilting and lifting is probably a bleeding issue introduced after all my line replacements (it is fed by a separate pump, I believe) which will cure itself. There is one interesting side effect. Before the line replacements, the tilt cylinder slowly creeped "down". This is now gone. But perhaps it's a result of the angle I left the bucket in after the repair of the lines. In short, I have noticed that the cylinder geometry changes dramatically with the bucket angle, so if the seals are leaking, there would be a marked change in the bleed-by if the bucket is left in one position versus another due to the forces and cylinder geometry involved.
Forward and backward motion problem is probably unrelated. If I have the brass filter, which I'm pretty sure I don't, then this may explain the absolute lack of motion power. The only other option is that the pump is bad. If I pull the left "yankem" , the motor labours a little which means that the motor is working against something. I have not noticed that the right "yankem" does not do the same, but there is very little motion. Both yankems seem to be in teach mode - creep forward or back, with the left adding a bit of engine strain. But then again, I am learning to drive a half-not working Bobcat in a garage that does not belong to me and so am trying to minimise the carnage while trouble shooting - and not asking questions that have been answered 100 times.
More reading required...

 

[mahans7]

Thanks Mike. I hope the pictures help someone else like me that was new to Bobcats and didn't have the faintest idea what was being spoken about on initial read. I would have prefered if I did not have to take them though.
Been reading and just realised that I have two, hopefully independant problems.
Jerkiness in tilting and lifting is probably a bleeding issue introduced after all my line replacements (it is fed by a separate pump, I believe) which will cure itself. There is one interesting side effect. Before the line replacements, the tilt cylinder slowly creeped "down". This is now gone. But perhaps it's a result of the angle I left the bucket in after the repair of the lines. In short, I have noticed that the cylinder geometry changes dramatically with the bucket angle, so if the seals are leaking, there would be a marked change in the bleed-by if the bucket is left in one position versus another due to the forces and cylinder geometry involved.
Forward and backward motion problem is probably unrelated. If I have the brass filter, which I'm pretty sure I don't, then this may explain the absolute lack of motion power. The only other option is that the pump is bad. If I pull the left "yankem" , the motor labours a little which means that the motor is working against something. I have not noticed that the right "yankem" does not do the same, but there is very little motion. Both yankems seem to be in teach mode - creep forward or back, with the left adding a bit of engine strain. But then again, I am learning to drive a half-not working Bobcat in a garage that does not belong to me and so am trying to minimise the carnage while trouble shooting - and not asking questions that have been answered 100 times.
More reading required...

PB, thanks for the pics, I'm relatively new to skidsteers and it helps a lot to see the pics. The guys here are good about answering questions even if its been asked 100 times.

 

[peebeeaitch]

PB, thanks for the pics, I'm relatively new to skidsteers and it helps a lot to see the pics. The guys here are good about answering questions even if its been asked 100 times.

28 Dec 2012
This is a view of the hydraulic "bay" under the seat:

And a close up of the block:

I immediately noticed a problem with the left yankem. Pushing the stick forward, till I felt a little resistance:

And back till a little resistance:

The cause:

However, I won't be worrying about this now as I still can't go forward or backward!
Again I tried to find the brass 40um filter, but if it is there, it is hiding behind the fitting that is probably 1.5" AF. I will need to get a bigger wrench this morning.
Did get the neutral charge by-pass valve out and it looks quite good:

With a close up of the slightly burnished valve body:

(I assume the slight valley on the fitting is no problem. It bothers me a little that there was a slight sliver where the spring end must have shaved some of the fitting off).
Temp switch was removed and inspected. Originally I thought the silicone was there for a reason, but now I realise that it was cosmetic. What is not cosmetic was the little residue that I found on the oil side of the unit. Luckily it had adhered to the spigot and not started a ride through the hydraulic system.

But now I need help. This is the oft-repeated sketch from the manual (in various different views throughout the hydraulics section):

Looking at mine (I have labelled it with what I think are the correct sources, in the same colour as the manual):

Is this correct? The page from the manual does not indicate the line to the hydrostatic pump so I assume that my block is from the newer series that the manual indicates - machine serial is 4995-14265. The manual does show the hydrostatic feed line in the coloured Hydraulic System Operation section.
Is it possible that the brass filter is hiding behind the huge charge pressure fitting?
TIA.

 

[ancomcabs]

28 Dec 2012
This is a view of the hydraulic "bay" under the seat:

And a close up of the block:

I immediately noticed a problem with the left yankem. Pushing the stick forward, till I felt a little resistance:

And back till a little resistance:

The cause:

However, I won't be worrying about this now as I still can't go forward or backward!
Again I tried to find the brass 40um filter, but if it is there, it is hiding behind the fitting that is probably 1.5" AF. I will need to get a bigger wrench this morning.
Did get the neutral charge by-pass valve out and it looks quite good:

With a close up of the slightly burnished valve body:

(I assume the slight valley on the fitting is no problem. It bothers me a little that there was a slight sliver where the spring end must have shaved some of the fitting off).
Temp switch was removed and inspected. Originally I thought the silicone was there for a reason, but now I realise that it was cosmetic. What is not cosmetic was the little residue that I found on the oil side of the unit. Luckily it had adhered to the spigot and not started a ride through the hydraulic system.

But now I need help. This is the oft-repeated sketch from the manual (in various different views throughout the hydraulics section):

Looking at mine (I have labelled it with what I think are the correct sources, in the same colour as the manual):

Is this correct? The page from the manual does not indicate the line to the hydrostatic pump so I assume that my block is from the newer series that the manual indicates - machine serial is 4995-14265. The manual does show the hydrostatic feed line in the coloured Hydraulic System Operation section.
Is it possible that the brass filter is hiding behind the huge charge pressure fitting?
TIA.

Yes that is where it is, or was on mine anyways

 

[peebeeaitch]

Yes that is where it is, or was on mine anyways

continued...
The required socket is 1.5". Plus tommy bar. Plus hammer.
Is there an easy way to pry the filter out? Eventually I used the spring with a screwdriver jammed in (gently) between the spring and filter and a long-nose gripping the spring to gently ease the filter out.
Anyway, here it is:

This really does not look that gunged up. If I hold it and fill the "bowl", almost no oil leaks out through the filter. Is this correct?
TIA