I recently bought an 1845c at auction based on video, pictures and it's reputation as being "bulletproof". The seller disclosed a hydraulic leak, but claimed unit was operating properly. (I did notice after the fact, that in the video demo the driver only made left turns). Well it turns out the reason for the left turns was the left drive motor is shot. Case dealer says to replace both motors and tandem pump as the whole system could be contaminated. Unfortunately 8-10k in repairs is not in my budget and not worth spending on this machine anyway. My question is has anyone just replaced a bad motor while leaving the rest of the system intact? If so what were the results?
It would be OK to just fix the crook motor but the entire hydraulic system needs to be cleaned and thoroughly. This should be done anyway irrespective of how far you get into it.
Thanks for the advice. Would you try to pump some solvent or diesel fuel through the system or remove everything (hoses pump, etc.) to flush?
I think there's a product that is used to flush hydraulics but can't remember what it's called. Others may know.
You may want to have someone come out with a filter cart. You can purchase your own but they are around $2000
The dealer wants to protect themselves when they say to replace the whole unit. Some people will go back on the dealer if they just replace one drive and then contaminated parts get into the rest of the hydrostat system.
Makes sense Tom, so if it were your machine you'd just replace the bad motor? That seems to be the favored solution. Thanks for your input.
I would drain the hydraulic system, look at the oil and run a magnet through the oil after it sets in a bucket for a day and see if there is metal on the magnet. Cut the filter apart and look for metal. If all looks good, I might put a motor in and run it. You have a 50-50 chance of getting by.
If it was my money I would just replace the motor and see how the rest of the machine is Now that you know the proper answer and the risks involved the choice is yours only Flushing is fine but nothing short of pulling every single part of the system down for rebuild or replace will ensure that there is not metal waiting to cause future problems
Guess I'm somewhat on both sides of this question. I'm thinking if it was mine and the only person I had to answer to was myself my approach would be as follows: First pull filter and cut open to inspect for nasty crap. Second would be to remove motor suspected to be the problem, strip and inspect for damage. Third I would do the same with the pumps, both right and left. As they share the same oil and filters and again inspect for damage. Once you have that much done you should know what the real problem is and what really needs to be replaced. Maybe it's just me but I have a problem with someone telling me the motor is bad unless they have at least done some serious troubleshooting, more than just a quick run around while sitting in the seat. I just thinking that the pump creates the flow and pressure and the motor converts it back to motion. Heck the problem could possibly be in the control valve on the pump, I forget if there is a pressure relief valve in the system if so that could be the problem! Did this machine come with a service manual, not just a little operators manual? If you plan on keeping this for any amount of time a real service manual and parts book would be handy, not sure if those are available online.
Never replace a failed motor on a hydrostatic system without repairing the pumps as well - & thoroughly cleaning/replacing all associated hoses & coolers. If the motor has self destructed - it HAS taken out the pump as well. When a new motor is installed with a bad pump - the pump will send trash to the new motor & you will kiss it goodbye within a few hours of operation. You maybe lucky however, those motors do have an oring that blows & causes loss of drive. Like @kshansen says, you need to do some tests & pull that motor out & strip it to see what is actually going on. Here is a thread to help - which links to some others as well.
When a hydraulic motor let's go most of the debris is in the casedrain and that usually has a filter. I have had track drive motors fail and the pumps remained in spec and weren't touched. Each time it happened new filters were fitted and at the end of the first days work the casedrain filter was changed. A lot depends on how long the machine has run with a buggered motor, mine was shut down immediately.
Thanks for all the advice guys. I think I'll start with the suspect motor and the filter to see what I find, and go from there. I'll post what I find. Thanks again.
Probably goes without being said but, keep in mind that in hydraulics a prefect pump putting pressure to a worn out motor will have the same result as a perfect motor connected to a failed pump. As they say "It takes two to tango"! Actually it might be more of a threesome when you factor in the valving but then that is part of the pump in this application!
If I switch motors to opposite sides and the problem moves to other side, that would confirm bad motor theory right?
The design flaw on an 1845C is the lack of case drain filters. My Bobcat 863G machines did have the case drain filters in the case drain circuits. Having 3 of these (auctioned the 4th one off years ago), the only way to get back to normal is to repair (replace) the rotating groups in both drive motors and pumps. Last one I did was 10 years ago, and it was $5500 for a pump shop to repair the pumps and motors that I handed them in a box. I've got another that needs it as one side has near zero torque.
If it was listed as "BulletProof" did you try shooting at it ? Some of the steel on them things is quite thick....
I agree with Kshansen. 1st investigate if it is in the fact the motor is bad. Then inspect the motor. If there is a lot of wear in the motor, then you want to thoroughly flush and clean the entire system. I've replaced both motors in my skid steer but it was due to them leaking into the chain case. For sure cut the hyd. filter open and look for metal filings. I rented a filter cart from a hyd. shop and ran the new oil through the system several times.
I would think that would be one way, if problem follows the part being moved then the part is the problem. I've used that method for different things over the years, like injectors in an engine. One point I'm not sure has been addressed is whether the problem is in fact hydraulic in the first place. You may have checked already but a broken chain, stripped splines in a gear or bad gear reducer could also cause a problem. I know your post said "Case Dealer" says pump is shot, has this person or dealer actually worked on the machine or are they just guessing from a description of the problem? I don't recall you giving the serial number of this 1845C but seem to recall that some, older ones?, had a speed reducer between the drive motor the chain box gears.
Did some digging and found this: https://www.messicks.com/commoncatalog?vendor=cas&modelId=140814 Looks like a good on-line parts book! Anyway I see in the power train section where it show the motors there was a change like I thought. Up to serial number JAF0067457 they show a planetary gear reduced and one style of motor. Then from JAF0067438 and up there is a different drive motor and no planetary gear reducer.
A real potential problem with swapping the other motor to test if it's bad is contamination. If the motor is shot you don't want to further contaminate the system.
It easier to check the casedrain oil flow. That will tell you everything you need to know other than you know the motor ain't working. There's no need to overthink this problem.
Haven't really determined the motor is the problem yet but could check the case drain for sure.
Wasn't paying attention. Was the hydraulic filter cut open and examined? Any brass present?
Considered it for sure
Not yet
Good point.
I'm new at working on this stuff so forgive my ignorance, but how do you check case drain flow?
Mine is #JAF0178850, I don't know if this helps, but I'll check out the parts book. Thanks