I’ve been trying to track down a fairly serious leak in my foot control t190 for quite a while and have failed badly so far. The leak shows at the inspection plate below the fuel tank and the hydraulic tank slowly drains. I have no trace of fluid under the hydraulic tank or anywhere in the valve compartment. Also nothing showing in the engine compartment. I’m about to pull the engine to see what could be going on. Anyone have an idea?
Check the suction hose clamps on your hydraulic tank and pump first.
Thanks Vetech. I’ve had the side panel off with the track removed and couldn’t see a drop anywhere around the tank. It’s almost like it would be below the main drive, but I can see all 4 hoses clearly and nothing there. A horrid thought would be to have some kind of leak in the drive itself.
Like Vtech stated, check around the pump. You might need an inspection mirror to see the back side as it's tucked back in there, but any leak at the pump will drop oil in that belly that the fuel tank sits in and will leak where the fuel tank drain plug cover is. I've seen Bobcat pumps crack before and leak oil like yours.
Thanks Willie59. I have been kinda leaning toward some kind of problem with the pump or drive on the bottom side. I'd replaced the pump several years ago, although not many hours, so I was skeptical it could be that. It's also a super tough place to get clean enough to see even with hot water pressure. I'll admit that I haven't been able to see the bottom of the pump suction line. I'll go try and remove enough things to clean and see now.
Actually, sometimes to find a leak it's better for it to remain dirty and not clean it, the leaking oil trail will wash dirt away, at least somewhat, and that oil cleaned trail will point you to where the leak is.
Good point Willie. I did grab my inspection mirror and gave the backside of the pump and drive a good look and found nothing. I'm convinced that the leak has to be originating from the bottom area. I've almost talked myself into removing the engine rather than just the pump. It really doesn't look too hard to remove the engine and it would allow an inspection of everything. Does this make sense to you?
I believe you can remove other things to gain even more viewing access before you have to go that far.
Thanks Vetech. Unfortunately the only thing I see that can be removed for better viewing1 is the engine…aargh
Remove the engine, go for it. Keep in mind though, once you remove that engine, oh, and the drive pumps and work pump come out with it, it's all mounted in a cradle, but once removed, if the source of the leak isn't clear to see, you now have no chance of running it to find the leak. And to remove the engine/pumps you have to access the suction line at the work/charge pump and disconnect it, not easy to get to, but that's what's required. Also have to disconnect the work/charge pump output hose as well as the four drive hoses, be sure and have the JIC plugs to plug those hoses, especially the drive hoses, don't want to get any dirt in those hoses. And mark them, don't want to mess up when you go to reconnect them.
thanks Willie. I read through the removal steps in the manual and realize what will be visible and what won’t. The problem is that it really doesn’t show any more leakage running than sitting. I never see a trail left as I drive it, it just shows a puddle when parked. When watching the drip under the belly pan it’s steady enough to see it drip a couple times a minute when not running. When running it barely shows. I’ve got about 3 months of trying to find the darn thing and I’m about at the end of my ability to find it other wise. I really don’t know what I can remove to get a better look. I’ve got great lighting and a good mirror and see nothing. I do appreciate that you and Vetech can only make so many suggestions, and thanks so much for them.
I feel your pain, and though I don't now, I've worked on Bobcat machines for years so I know exactly what you're dealing with. No, I have no easy answer, easy and Bobcat doesn't work in the same sentence. All I can advise is be persistent, keep looking, using swear words is perfectly acceptable under the circumstances. Using this method I've always, eventually, been able to say "there you are!". Another thing to look at is the pintle shaft seals for the drive pumps. You can't really see them with the pintle arms and drive neutral plate installed, but look for evidence of oil on top of the drive pumps.
This is exactly what a suction line leak does. Try this before pullng the engine. Warm the machine to operating temp. Shut it off once your are there and start looking around the suction lines for very small leaks. What happens is when the machine is shut off, the tank will have increased positive pressure........which in turn will allow leakage out of the suction side of the system. When running, even though there may be some positive tank pressure, the suction of the pump alleviates that which stops the leak. Very bad suction leaks will allow air into the system and create cavitation.
Thanks Willie and Vtech. I'm going to put my coveralls on and start looking before leaping!
Ok, I went back to the shop and found the hydraulic schematic in my parts manual. I hadn’t realized that there was a connection that Vetech was talking about because it was packed solid in mud. To go back a little, We hadn’t realized that we’d lost one of the inspection covers on the belly pan last winter and after wading through mud 2ft deep a bunch of times on our job, we managed to pack the entire belly pan with mud an inch above the bottom of the hydraulic reservoir. It wasn’t until I saw a leak that I discovered the mud. I spent literally 8-10hrs cleaning and and ended up fixing leaks that were caused by the rock hard dried mud jamming against fitting. So anyway, today I scraped mud away from the suction hose connection but couldn’t get a whole lot done without removing the 2 hoses on the drive. I Loosened the upper hose and realized that I can’t get it off without removing the other end but it’s pretty well captive between the Elbow and hose. Do I need to back off the motor to make this happen, or is there a better way? The manual is kinda sketchy in this case.
A pic of this would help.
I can’t get a pic today, but it’s the hose from the drive to the motor. They are both short and very stiff with a female swivel on both ends so they’re trapped between the two male ends. The manual says that when the engine is installed you must connect the drive hoses before seating the engine or the connection is too tight to be made. I’m trying to do the opposite and find the hoses too stiff to remove, so I went to the other end to relieve the pressure and it didn’t help. All this is to be able to access the suction fitting which is behind the two drive hoses. Do I back off the drive motor from the chassis or is there another way?
I want to thank Vtech63 and Willie59 for their help with this problem and update the results of their help. Vtech was absolutely right on with the suction hose diagnosis. I backed off the track drive motor so that I could remove the two hydrostatic drive hoses which revealed the suction hose. The clamp was encased in mud which after I removed, I could see that oil was coming from that area. I was worried that the metal hose could have rusted through, but after testing it, I decided that it was the hose connection itself. I installed a new hose and put her back together with no leaks. Thanks again for your help.
Good to hear you got it sorted out. Yeah, takes some digging, that's just the way it goes working on those machines.
Good deal!