? on D4G with final drives leaking

[bwh186]

Hi everyone. I am new here and enjoy reading your posts. I have learned a lot and have a question for you.

Our D4G started leaking oil out of both final drives at the same time. We found a line that went to both of them and figured it was going to a breather that was clogged, but it goes to a block towards the front of the machine with other lines connected to it.

We checked the oil levels a couple of times, and they were fine with no pressure built up in the housings either.

Don't these finals have to have a breather or something? We have failed to find it so far. 800 hours doesn't seem like enough for the seals to be leaking yet and this dozer is well taken care of. It is odd that they would both leak at the same time anyway.

Any help is appreciated. Thanks.

 

[MitchSA]

Not sure on a dozer but excavator final drives have no breather. Again on the exc, there are 2 smaller lines. One for high speed and one for a park brake. Dont think dozers have 2 speeds so it must be a park brake line? I'm sure someone with more dozer experience will be here soon. Clean them off, check/top up levels and work it. Just keep a close eye on it, those things are EXPENSIVE to repair. Good luck.

 

[JeremiahSr]

Don't think that machine has a breather. The line you see is the brake release hose. If it's leaking right behind the sprocket it is the seal. Check oil level though, sometimes the drive motors will overfill final with fluid and the oil gets pushed out at sprocket seal.

 

[nzpatch]

is it final drive oil or hyd oil? the brakes will be hyd release so you can work out where the oil is from from the type/smell.

 

[inyati13]

The final drives are driven by a hydrostatic transmission (not sure transmission is used in the same sense as a car). The dual hydraulic pumps forward of the hydrostatic transmission are located under the operators feet. You pull up the floor mat and there is a pnal there to access the pumps and hydraulic lines. Going back to the drives. There is a dual system of lines that go from the pump to the vchydrostatic drive that powers the two final drive motors. My best suggestion is to get on one of the Cat dealer web sites and go to the section on parts. You will find the schematics for the final drives under the power train section. They are good diagrams and you will be able to figure out whether this is a hydraulic oil leak or the drive oil leaking. Remember the hydraulics and transmission oil are one and the same as the D3, 4, 5 Gs are all hydrostatic.

 

[bwh186]

Thanks to MitchSA, JeremiahSr, nzpatch, and inyati13 for your replies. You have helped us figure out

1. There is no breather on the final drives. The lines we thought went to a breather are actually park brake lines. This makes sense because they come in between the final drive and drive motor.

2. The leak was dripping from behind the sprocket, and we assumed that it was final drive oil. We need to make sure of this, though, because it could be hyd. oil. Definitely need to check this closer and make sure.

We plan to run it this week and will keep a close check on it. Thanks again for your help.

 

[bwh186]

inyati13,

We have been waiting for access to be granted to us to the "Partsonline"(?) service through the local dealer. When you sign up it says it takes 3 days for approval. I think we have waited about a 10 days. I will try to check this week on what the problem is with this. Maybe they are going to deny us access! Thanks.

 

[inyati13]

Glad to help. I just went on our Whayne Dealer's PartStone Online. The partstores are all Cat software so yours should be the same. The brake group is under the power train section. By the way, the partstore is not as user friendly as I think it should be. I mentioned this to my dealer and he did not disagree. Anyway, the brake system looks to me like it also operates off the same hydrostatic oil. I am only guessing as the brake group diagram is not that good! You should call the dealer you are registering under for the partstore. I had the same problem getting an account. I called and I was on the same day I called.

 

[wsw]

First off with Toromont you need to open an account before you can get SIS. how bad are they leaking because the oil will have to be going down somewhere on the D4G you also got case drains on the drive motors although I would suspect if they are plugged it should push oil past the speed sensors located on the sides of the motor. keep an eye on the final drive level as it would be more noticable if the leak is small. I might have pics already of the lines, if Toromont doesn't get you on SIS fast enough you can e-mail me nhe@nor-del.com and I can probably e-mail pics. or I can tell you where the lines go