There is a simple test you can do with an inline flow meter. Any hydraulic shop should have one. Put the flow meter in a line to the lift cylinders and run the machine. Observe the flow rate when cold and do the same once the machine is at operating temperature.If the flow rate is almost the same then the seals are your problem. Even small hydraulic shops should have some form of flow meters. (I have done it before with drums but you need to be very careful once the oil is hot and under pressure)
If it is dropping at a rate of 1" every three seconds then it is a considerable leak and will be much worse once the oil is hot. On the subject of oil, does it have the correct grade of oil in it? One thing tells me it could be the seals. I have an old Hymac excavator with leaking lift cylinder piston seals. It goes down about an inch every second or two. I have had to adjust the control valve from its factory settings to get a reasonable speed in the lift but still nowhere near as fast as it should be.

To someone with out any hydraulic knowledge the system appears to be very complex but in actuality it is a fairly standard pilot operated load sensing system. With the information in that document a hydraulic shop should be able to at least identify where the problem is but as you said it will take money even to fault find let alone fixing the problem.

Shame we are on differrent continents as I would have liked the opportunity to help out in person with the issue.

This is the oil I have been using in the HYD system:  www.tractorsupply.com/tsc/product/travel...ine-oil-sae-30-5-gal

A no longer with us ACMOC poster recommended I use SAE 30 Diesel engine oil in the HYD system as opposed to the more expensive CAT oil, primarily because I can never seem to get rid of all the leaks. I really need to fix the leaking pump to tank return hoses as they weep continually with the machine off etc.

As for flow meter, just an inline type that can handle the pressure?  www.royalhydraulics.com/index.php/flowmeters

Yeah, instead of paying a dealer to come look at it, I wish I could pay a retired mechanic or whatnot...

Engine oil is generally not recommended for use in hydraulic systems especially systems with a piston pump except for some reason Cat machines. My 305CR is supposed to have engine oil in it according to the Cat manual.
www.machinerylubrication.com/Read/29715/hydraulic-engine-oils
gives a good explanation of the difference between the two and the drawbacks of using engine oil instead of Hydraulic. One thing to note is the viscosity of the oil. I was always taught to use ISO 32 or ISO 46 for piston pump based systems but SAE 30 equates to ISO 100 which is generally only used in gear pump systems.
Whatever I was taught Cat systems are designed for and run with SAE30 and that is one of the oils Cat says is suitable for their systems. My 305CR manual lists about a dozen different oils that are suitable at various temperatures and SAE30 is one of them.

According to the webiste the maximum pressre is 6000psi but if you open the pdf speciifcations it lists the pressure at only 350psi which is of course no where near enough. Otherwise that style of flow meter will work but you will most likely need a fairly large one (possibly 1" to 1-1/2") which may be expensive plus fittings. I don't know what fittings are used on the older excavators like yours but mine uses JIC which are very common. You will also need to find one that can handle flow in both directions or you will need to have a bypass for reverse flow so you can lower the boom after the test. If you revese the flow through some flow meters you can damage them.

Having owned numerous excavators my advice is that you can't afford to restore these machines with the first generation of moderen hydraulic systems with $150/ hour service calls for a mechanic and service truck. Cat isn't interested in serving older machines any more so parts request come up obsolete or the prices have been dramatally increased, thanks to the MBA's of this world. You might consider selling the equipment and using the funds to hiering a contractor to do the work or renting a newer machine and doing the work yourself.

Having owned numerous excavators my advice is that you can't afford to restore these machines with the first generation of moderen hydraulic systems with $150/ hour service calls for a mechanic and service truck. Cat isn't interested in serving older machines any more so parts request come up obsolete or the prices have been dramatally increased, thanks to the MBA's of this world. You might consider selling the equipment and using the funds to hiering a contractor to do the work or renting a newer machine and doing the work yourself.

rturn3060 wrote:

Having owned numerous excavators my advice is that you can't afford to restore these machines with the first generation of moderen hydraulic systems with $150/ hour service calls for a mechanic and service truck. Cat isn't interested in serving older machines any more so parts request come up obsolete or the prices have been dramatally increased, thanks to the MBA's of this world. You might consider selling the equipment and using the funds to hiering a contractor to do the work or renting a newer machine and doing the work yourself.

Selling both the 225 & D6C as-is would be an option, but it would not be to hire a contractor, it would be for upgrading to newer machines. Not going to hire a contractor to dig a pond, I prefer to do that kind of work myself. But to be honest, I'd prefer to stick with the older non-computerized equipment for my hobby purposes. I like working on these machines myself as well, however I find the lack of specialized tools and a shop with a ~5 ton bridge crane is sometimes a bummer lol. 

And yes, initially I asked how would I go about finding somone to look at the 225, because I feel the Dealer route is a non-starter. They likely don't want to mess with little old hobby machine/cheapo customer me and my 43 year old excavator. However, looking at that Tee-Test Tools kit required, I question wether or not somone would have all that equipment lying around...  I can handle making all the adapters, hose assemblies & blocking plates & whatnot, the meters are what would be the challenge.
 

Hi Team,
in my experience 10W Hydraulic oil should be used for all temperatures in these axial piston pump systems as detailed per my school notes photocopy of the Lubrication and Maintenance Guide, Form No GEG02140-02.

In cold weather the axial piston pump plunger/piston shoes have been known to pull off the pistons in these and other applications if the Pre-Operation Warm-up Procedure and Warnings for the Hydraulic system oil, as detailed in the Operator's Guide, Form No SEBU5339 are not adhered to.

Cheers,
Eddie B.

Hi Team,
in my experience 10W Hydraulic oil should be used for all temperatures in these axial piston pump systems as detailed per my school notes photocopy of the Lubrication and Maintenance Guide, Form No GEG02140-02.

In cold weather the axial piston pump plunger/piston shoes have been known to pull off the pistons in these and other applications if the Pre-Operation Warm-up Procedure and Warnings for the Hydraulic system oil, as detailed in the Operator's Guide, Form No SEBU5339 are not adhered to.

Cheers,
Eddie B.

edb wrote:

Hi Team,
in my experience 10W Hydraulic oil should be used for all temperatures in these axial piston pump systems as detailed per my school notes photocopy of the Lubrication and Maintenance Guide, Form No GEG02140-02.

In cold weather the axial piston pump plunger/piston shoes have been known to pull off the pistons in these and other applications if the Pre-Operation Warm-up Procedure and Warnings for the Hydraulic system oil, as detailed in the Operator's Guide, Form No SEBU5339 are not adhered to.

Cheers,
Eddie B.

 

Thanks for pointing that out Eddie. My operators manual for my 305CR lists a straight 30W viscosity oil for use in temperatures 10 to 50 degrees C which does not make sense given the type of hydraulic pump.

My 305CR is non computerized but still has an overly complex electrical system. I still think your best bet would be to talk to a local hydraulic service shop. Does not need to be a huge shop.
If you sell the machine you have to find a replacement, in Australia that size machine would set you back at least $50,000 depending on how new you want to go. I don't know what a 200 series would be worth in the US but most machines seem to be very cheap over there at least compared to here.
If it was me I would be looking at the machine condition as a unit; If the engine is good, pivot pins and bushes are good, walking gear is good (or at least still has some life left in it), little or no rust then I would keep it and spend the money to solve the problem  however if any of those items are not in good condtion then fixing the hydraulics will only be the start.
I also don't know about the availabilty of parts for that series direct from Cat but there are numerous wreckers and spare parts dealers that should be able to help out.
Unfortunately it will take some money to find the cause of the issue. Perhaps someone in you local ACMOC chapter could help out either directly or by passing on your details to some one who can.

A couple of other things I would try though, and I don't know how easy or difficult it would be to do.
1) Run the machine until the fault occurs and swap the pilot lines from the lift valve to another control valve, If the problem moves with the hoses then the pilot control valve is fine.
2) Run the machine until the fault occurs and swap the hoses from the bucket to the boom lift and vise versa. If the lift speed is still slow then the valviing is not at fault. If everything is hard piped to the valving then this might be difficult to achieve. I wouild also imagine that the other functions would have a lower flow rate so it would naturally be slower.
Keep in mind the oil will most likely be very hot.

Regards

Phil

PhilC wrote:

edb wrote:

Hi Team,
in my experience 10W Hydraulic oil should be used for all temperatures in these axial piston pump systems as detailed per my school notes photocopy of the Lubrication and Maintenance Guide, Form No GEG02140-02.

In cold weather the axial piston pump plunger/piston shoes have been known to pull off the pistons in these and other applications if the Pre-Operation Warm-up Procedure and Warnings for the Hydraulic system oil, as detailed in the Operator's Guide, Form No SEBU5339 are not adhered to.

Cheers,
Eddie B.





 

Thanks for pointing that out Eddie. My operators manual for my 305CR lists a straight 30W viscosity oil for use in temperatures 10 to 50 degrees C which does not make sense given the type of hydraulic pump.

My 305CR is non computerized but still has an overly complex electrical system. I still think your best bet would be to talk to a local hydraulic service shop. Does not need to be a huge shop.
If you sell the machine you have to find a replacement, in Australia that size machine would set you back at least $50,000 depending on how new you want to go. I don't know what a 200 series would be worth in the US but most machines seem to be very cheap over there at least compared to here.
If it was me I would be looking at the machine condition as a unit; If the engine is good, pivot pins and bushes are good, walking gear is good (or at least still has some life left in it), little or no rust then I would keep it and spend the money to solve the problem  however if any of those items are not in good condtion then fixing the hydraulics will only be the start.
I also don't know about the availabilty of parts for that series direct from Cat but there are numerous wreckers and spare parts dealers that should be able to help out.
Unfortunately it will take some money to find the cause of the issue. Perhaps someone in you local ACMOC chapter could help out either directly or by passing on your details to some one who can.

A couple of other things I would try though, and I don't know how easy or difficult it woule be to do.
1) Run the machine until the fault occurs and swap the pilot lines from the lift valve to another control valve, If the problem moves with the hoses then the pilot control valve is fine.
2) Run the machine until the fault occurs and swap the hoses from the bucket to the boom lift and vise versa. If the lift speed is still slow then the valviing is not at fault. If everything is hard piped to the valving then this might be difficult to achieve. I wouild also imagine that the other functions would have a lower flow rate so it would naturally be slower.
Keep in mind the oil will most likely be very hot.

Regards

Phil

I would prefer to fix what I have in both the D6C (10K401) and the 225LC (51U2607).

I will have to look in my manuals, but I seem to recall mine listing 30W for the HYD system, hence Bob Ont recommending I use 30W Diesel Engine oil...

The 225 needs quite a bit of small repairs, nothing high dollar, unless this HYD issue turns into a high dollar issue, which is what I am aiming to figure out.

Attached files are when I bought the machine in 2007 (I think it was 2007), and one from a few years ago showing most of my equipment.

Have done a bunch of work on it here and there:  imgur.com/a/UxGTA   imgur.com/a/0GrQQ   imgur.com/a/4RWu9   imgur.com/a/C6yiC  

I paid $23,000 USD for the machine, they sell for a similar price these days.  When I bought the machine the previous owner had just put on new CAT chains. But then the machine sat for years right after that and kinks in the pins & bushings developed ( imgur.com/a/5XNFq ) and I have never been able to free them up, tried various methods recommended to me on this site. 

As far as the rest of the UC, there is a broken track adjust spring, a rusted out plug on one of the final drives letting water into it, can't seem to remove/replace that plug unless the sprocket is pulled, top rollers and idlers need to be replaced or built back up and machined, pads are loose (due to improper torquing by prev owner when chains were replaced) and many of them bent, both final drives are getting overfilled with HYD oil from the parking brakes.

There are various leaks due to needing O-Ring replacement on many hoses (CAT flange hoses), still many hoses to replace eventhough I have replaced many already over the years. Both boom cylinders and the bucket cylinder need to be resealed as well as need new spherical bearings. As far as pins go, they seem decent but of course not perfect. I'm sure line boring would be in order to bring everything back to spec. However the only pin that is very loose is at the bucket cyl rod eye, and that is due to a wiped out bearing not so much the pin.

It's unlikely selling this machine, then searching for another one in the $20-30k price range would be of any benefit in terms of lessening maint/repair costs. I'd likely need to spend 2X the money when buying the replecement. So unless there is something catastrophically wrong with my 225, it seems the best course of action is to get it up to decent snuff for one more large project.

And up to this point in time, parts availability for the D6C and the 225 has been pretty good from CAT.