2018 Toolcat 5600, 2100hours, barely moving forward or backup after a hose break repair

[Interceptor]

The gearbox is vented to relieve any pressure caused by temperature changes. Any significant pressure in the gearbox would indicate a blocked vent. That could be the cause of the oil leak at the axle, but wouldn't cause the drive issue. High oil level in the gearbox would indicate either a brake piston leak, or a motor shaft seal leak. Either one of these would also put some pressure into the gearbox, but it should immediately be released out the vent. There is a breather at the top of the gearbox, make sure it's not blocked.

If one or both brake pistons are leaking, the oil level in the gearbox will gradually increase whenever the brake is released (when driving). I can't say for sure how fast it would rise, it would depend on the severity of the leak.

I think a charge pressure test is a good next step. If that checks out I'd test drive loop pressure. Have you tried to run it with all four wheels off the ground?

 

[RichardV-Quebec]

Interceptor, thanks for sticking with me on this problem. No, I have not jacked up the TC yet but I just realized that if I do, this would possibly tell me if the brakes are the problem. I saw the vent on the front transxale, was not blocked (eyesight) but I ordered a new one last week and will put it on when I receive it. I don't think there was more 100-200 ml of oil that dripped off the check plug but it did spit oil 8 feet away (lucky I was not facing front of it)(I have had an oil shower before on a CASE 580 wheel check plug). Transaxle oil looks pretty nasty. Tomorrow should reveal more info. Thks again.

 

[RichardV-Quebec]

Up off the ground, only the rear wheels are turning in both forward/reverse direction. I tried moving the front wheels by hand and seemed locked. I did this when the machine was warm. I had no problem backing it outside the garage. Now I am going to change that hose and let you know.

 

[RichardV-Quebec]

I unplugged the front top motor hose from the drive motor to see if there was flow restriction with the repair and there is plenty of oil coming out the hose. The TC was in neutral, I did not expect that much oil pressure. Still working on the hose change. The other end of the hose is in a really tough spot to get to.

 

[RichardV-Quebec]

We dropped the front transaxle on the floor with the drive motor. Is there a way to just test the drive motor (to see if it turns when going forward/reverse with the hoses) ? The new hoses are in place on the pump side.

 

[ruffdog]

Did you ever figure out if the brakes were disengaging?

 

[RichardV-Quebec]

Did you ever figure out if the brakes were disengaging?

No, I don't know for sure. All I know is, when I jacked the TC up, only the rear wheels were turning. But on the ground, it would move forward or backward when cold, getting warmer it would stop moving making a weird sound, then I would increase the throttle and it would start moving again and eventually stop again. It did not feel as the brakes were on. I have the front axle on the floor now. Before I open the drive motor or the axle, I am not sure what I should do next. I never to got to try it with the new hose on because the mechanic who changed the hose decided to drop the whole axle down mainly because he was not able to unscrew the bottom bolt of the drive motor. Had I been there, I would have screw the new hose on and gave it a try. Anyways, I guess I could still try the drive motor to see if it turns while it is on the ground but I have to figure out what other hoses I need to block or connect. On the drive motor, there are the 2 big hoses and then there are the 2nd speed hose and the case drain(I think), then on the axle, there are 2 hoses. I suppose, 1 for the brakes (I can probably block that one) but there is another I don't know what it is for. That's where I am at.

 

[RichardV-Quebec]

Almost there... I have bought 6 feet long hoses for the motor and transxale, so I can test the drive motor aside(see if turns) and transxale while on the floor. When I started the TC, I got a 50-13 error code. Because I did not extend the 4 wires Deutsch connector. Now ... my reasoning is ... If that wire matters and it did not complain about the speed sensor before while having the problem, does it mean it thinks the transxale is turning when the wheels are not !?

 

[RichardV-Quebec]

Update. I hooked all the hoses and speed sensor while I have the drive motor and the transaxle separated on the floor. Started the machine, forward/reverse only the rear wheels are turning but not the motor gear. Notice, I pressed the fast speed button on the left lever and the rear wheels also stopped turning while lever was in forward position. Did not try reverse. The yellow light came on the console to indicate traction control was off I suppose. From a youtube video (howIdidit) they are diagnosing a drive motor issue with a Bobcat skipsteer. They are capping the hoses and taking pressure. While not engaging forward/reverse they say it should read charge pressure and when engaging it should read 5,000 or so psi. Anyone agrees with this test ?

 

[RichardV-Quebec]

The gearbox is vented to relieve any pressure caused by temperature changes. Any significant pressure in the gearbox would indicate a blocked vent. That could be the cause of the oil leak at the axle, but wouldn't cause the drive issue. High oil level in the gearbox would indicate either a brake piston leak, or a motor shaft seal leak. Either one of these would also put some pressure into the gearbox, but it should immediately be released out the vent. There is a breather at the top of the gearbox, make sure it's not blocked.

If one or both brake pistons are leaking, the oil level in the gearbox will gradually increase whenever the brake is released (when driving). I can't say for sure how fast it would rise, it would depend on the severity of the leak.

I think a charge pressure test is a good next step. If that checks out I'd test drive loop pressure. Have you tried to run it with all four wheels off the ground?

Charge pressure is within specs on high idle. Almost 350 psi. I capped the front drive hose and only get close to 1000 PSI but I know the drive motor does not turn when the hoses were on. You wrote drive loop pressure, do you mean connecting the 2 hoses together and testing pressure on a T type connection?

 

[RichardV-Quebec]

Today, I started removing drive motor plugs as per TC-Service-manual and found debris which appears to be hose related in the relief valve hole. I think it was blocking the small 'HOLE' in the middle leaving the relief valve opened.

 

[RichardV-Quebec]

This is the video I filmed when I took out the relief valve from the drive motor. When I saw there was something in there, I started my phone video.

 

[RichardV-Quebec]

I then inspected the hose with the fitting we screwed in to make the joint and sure enough the inside of the hose has a cut in the rubber hanging loose ready to go in the motor to make more damage.

 

[RichardV-Quebec]

Well, what appeared to be a front drive motor problem is not! I needed to move the machine and capped the 2 break lines (I have traction control), the motor case drain and 2 speed hoses and connected the 2 big motor hoses together with a T union with a pressure gauge. Also I have a pressure gauge on one the break hose. The front transaxle and motor are removed from the TC. I backed up the TC from the garage and left it warm up. I noticed the pressure dropped to about 90 psi on the T connection with arm rest up. Arm rest down increases the pressure by about 20 psi. When switching forward or reverse and pressing the drive pedal, the brake line pressure varies from zero to 90-130. The TC won't move below 125 psi and makes that same strange sound from the beginning. The front equipment and steering are working fine. So I don't know what is going on. When cold, the charge pressure (at high idle) is 300+ psi but decreases rapidly after a couple of minutes. I suppose I could check the rear transaxle for excess fluid. I have no visible leaks. Any ideas anyone ?