Help with swapping hydraulic hoses to check weak track

[JimSage]

Greetings folks. I hope to get some advice whether what I'm going to do is a good/bad idea :

I have a pretty old mini excavator (IHI is4gx) and the left track is hardly moving now (in fact, it just jerks a little & stops when I try forward or reverse). I'm trying to figure out what is wrong, and I had someone suggested swapping the hydraulic hoses around for left & right tracks to see if the problem is with the KYB valve block OR possibly the LEFT final drive itself. Meaning, if after the swap the left track regains power & the right track loses power, then it means the valve block is bad (?).

So, I wanted to get some advice on 2 things :
(1) Is that a good way to test why the left track is so weak?
(2) If I do go ahead, do I swap both the top & bottom hoses on the valve block for each of the LEFT & RIGHT controls (ie. total of 4 hoses) ? I've marked the LEFT track hose as BLUE & the RIGHT track hose as RED. I'm told the hose just right below each of the marked forms a pair of the inlet & exit hose for each track.

Any suggestions/advice would be greatly appreciated! Thanks in advance.

 

[Peter 315]

Sounds good to me... You check the final drive for oil ? Does the track turn with no weight on it could the front idler be seized and binding up ?

 

[JimSage]

Sounds good to me... You check the final drive for oil ? Does the track turn with no weight on it could the front idler be seized and binding up ?

Thanks for quick response, Peter. I lifted up the left track in the air & it will move but very very slowly. The left front idler seemed free.

So, am I correct to say that if I do swap, then I will have to swap the 4 hoses? 2 for each track? I'm told the 2 hoses for each track is aligned vertically on the valve block ... just wanted to confirm if it is correct. Or can I just swap only the RED & BLUE hoses? (ie. just this 2 hose instead of 4 hose). Thanks!

 

[ptsg]

Thanks for quick response, Peter. I lifted up the left track in the air & it will move but very very slowly. The left front idler seemed free.

So, am I correct to say that if I do swap, then I will have to swap the 4 hoses? 2 for each track? I'm told they're aligned vertically on the valve block ... just wanted to confirm if it is correct. Thanks!

Yes, you need to switch the hoses by the pair. One pair for each motor. And yes, they are aligned vertically.

Also, if you take the covers off around the track motor, you may see 3 lines. One of those lines is the case drain. One good test that can also be done is to take the case drain out of the motor and just put a bucket or pan underneath. Rotate the track and if you get a lot of oil is coming out, the motor may need to be rebuilt. It's normal for the case drain to put out a small stream of oil but a lot is not normal.

By the way, it's the first time I see a mini excavator with a 5 speed manual transmission. Must cruise really fast down the road. :laughing:

 

[JimSage]

Yes, you need to switch the hoses by the pair. One pair for each motor. And yes, they are aligned vertically.

Also, if you take the covers off around the track motor, you may see 3 lines. One of those lines is the case drain. One good test that can also be done is to take the case drain out of the motor and just put a bucket or pan underneath. Rotate the track and if you get a lot of oil is coming out, the motor may need to be rebuilt. It's normal for the case drain to put out a small stream of oil but a lot is not normal.

By the way, it's the first time I see a mini excavator with a 5 speed manual transmission. Must cruise really fast down the road. :laughing:

Thanks, PTSG. I'm going to try that case drain test you suggested to see what's going on. Oh, lost the original knob & the 5-speed knob was just conveniently lying around ... lol

 

[/pine]

If it's believed to be a fluid/pressure issue...would a pressure gauge test not be easier ?

 

[CoyPatton]

I agree that you need to swap 4 hoses. Your forward and reverse directions are controlled by changing the flow direction of fluid, just like on a cylinder piston. If you only swap 2 hoses, you could have a collapsed hose and leave it in place and misdiagnose the issue completely.
A pressure test on the 2 lines would in my opinion be the better route to go for diagnosis. Run the test on both ends of the hose to check for an issue with the hose itself.

 

[racerboy832]

Is your machine a 40gx or 4 gx?

 

[JimSage]

If it's believed to be a fluid/pressure issue...would a pressure gauge test not be easier ?

hi Pine, unfortunately I don't have pressure gauges & attachments handy at the moment ... it will be on shopping list Our little hobby farm is way out in the boonies with limited tools available ...

 

[JimSage]

I agree that you need to swap 4 hoses. Your forward and reverse directions are controlled by changing the flow direction of fluid, just like on a cylinder piston. If you only swap 2 hoses, you could have a collapsed hose and leave it in place and misdiagnose the issue completely.
A pressure test on the 2 lines would in my opinion be the better route to go for diagnosis. Run the test on both ends of the hose to check for an issue with the hose itself.

Thanks CoyPatton, useful info for me! I have some basic mechanical knowledge but not as much in hydraulics