So have an interesting t190 1300hr, of the newest sn break a3l... Also had a newer t140 do this with 600hrs but customer needed unit back so could not continue to diagnose it. After getting it really hot and abusing it for an hour plus the steering levers get really hard to move. But if you let it sit for 5 mins it operates smoothly again until you run the crap out of it. Feels like the brakes are coming on, charge pressure ok, brake solenoid coil ok, voltage to the coil is fine. So I am thinking the valve for the brakes is acting up when hot, or that the brakes in the drive motors are sticking. Since this has happened on two units it seems may be a common problem? Anybody else had this? Thanks!
I haven't heard of this one, do let us know if you find the cause of this problem.
Does this machine use pilot controlled hydraulics? Is the hard handle in the handle or in the drive train?
The machine has selectable hand / foot controls.
ok. I was just wondering if the controls when operated were actually controlling pilot pressure to the control valve? I seem to remember that Bobcat has been famous for letting the operator choose if he wants to operate with hand or foot but after that is the control of the spool controlled by a linkage or a pilot signal? Don't really know if your hard handle is system related or hydraulic related. Definitely an interesting issue.
It is done by linkage, one from each lever to each hydrostatic motor.
ok. To me this sounds like it could be 2 things. Either the case drain is not allowing the pump case to drain which is creating excessive internal pressure on the pump swash plate or a problem with the swash plate servo piston or manual control valve if it indeed has one. The flow of the case drain line when measured with a flow meter should be below charge pump volumne. I'm guessing this flow goes through cooler back to tank so there may be a restriction in the cooler? Just throwing out some ideas.
Still not resolved but found some interesting things.. Used a portapower to pump the brakes up to 350psi (charge pressure) and drove it, felt fine. So as I worked it to get it hot and noticed the pressure drop to 310psi, still drove fine. Continued to work it and the pressure started to climb, it climbed up to 500psi before I brought it back into the shop because the levers had become too darn stiff to continue working it lol. So put a gauge on the line coming out of the motor just before the case drain. Had 30-50 psi, right where it should be. But once I started to work it the pressure dropped, and once the levers were stiff I had 0 pressure on that line. So up on stands it goes, I'll tear the track and what not off tomorrow and check the line to make sure it wasn't overcrimped or anything.. We have a t300 on demo right now, 40hours. Customer calls in and says my levers are a lot stiffer than my old unit? :Banghead*sigh* so that is a t140, t190 and now a t300 all of the newest serial number break with stiff levers. I wonder if anybody else is having these pop up?
andrew88 Did you figure out what the problem was on the steering? I'm having the same problem with my 05' T190.
Thread zombie lol. Yes they were in the drive motors. The new units had shuttle valves stuck, and the t190 was just abused. When things warmed up the pressure was leaving the working side and getting in behind the brake causing the brakes to drag and make the levers stiff.
Thanks for the reply back,didn't know if this post was dead.Anyways,like I said your situation is similar to mine, but with mine I was using it about a couple of months ago for about an hour or so then all of a sudden the right side track started to like freeze up the left side moved properly. When I let it sit for awhile (aprox 10 min.) it would be ok to use for awhile and would do it again.So I went to local Bobcat dealer and told him what happened and he had no clue what it was.I only use this around my home,no construction work.So,ever sence that time I have used it without any problems(put about 20 hrs. or so) til yesterday.Same thing.I've changed hydraulic oil,hyda. filter,case drain filters,charge filter about a couple of weeks ago.Everything else is OK,I bought this used W/1100 hrs. on it.This is my 1st skid loader,so don't know a whole lot about them.I did buy a service manual for it.Do you think I have the same problem?
I would love to have a t190 at home! Don't feel bad about the tech not knowing, I called Bobcat Techline during this and they all had no clue either. Had to figure it out on my own.. Could be, drive motors are around 3k so I wouldn't be changing it if it is not a continuous problem. I would get a few gauges on there and see what is happening when operating. Need to put one on your charge pressure so you know what it is for reference. Should be between 400-500psi. Than T in a gauge to the right side brake and see if the pressure changes during operation. Wouldn't hurt to have one T'd into drain case and make sure that does not fall off the face of the earth. You could be lucky and just need a seal kit, possible pressure is making it's way around the brake and that is what is locking it up.