Ok I have talked to 3 mechanics. 2 came out to house and test drove our 773g Bobcat. Both confirmed left drive pump is messed up. It has all kinds of power but its like an on off switch. Full power or nothing. Makes it a real pain to drive around. 1 Mechanic is a crane Mech. The other is a general Equipment Mech and the last is the shop foreman at Fabic Cat in St Louis. Non are Bobcat experts. So now that we know what the problem is. How do we go about fixing it? I'm 12 year IUOE crane operator and have some Mechanical skills but I am no mechanic 1 guy suggested pulling the whole engine. Other guy said you could get it out the front. 3rd guy just shook his head and said "HAVE FUN". ointhead Help? My searches on how to do it led me here. But I didnt find my anser. Hoping for some guidance.
if you really want to get to the pump, you can go either way, out the front, the fan/ blower housing is in the way, you'll also have to get the pulley off the drive side. pulling the eng/pumps is usually the lesser of 2 evils, 4 motor mount bolts, wiring, fuel system,cooling system and a few hoses. however... if only one side is causing the problem, check the case drain filter for debris , then i'd pull that side drive motor and take a look inside to see if the manifold seals are bad. if you dont feel any "pulsing" in the drive handle when moving, i'd be willing to bet on the drive motor being the problem :drinkup
Problem could also be the pintle lever has come loose from pump swash plate control shaft. Those things are almost uncontrollable if the pintle arm gets loose.
also very true, but i'd think if the lever was loose on the pintle shaft there'd be some serious steering creep, and the OP didnt mention that was an issue. heres what i'm thinking, if the seals are worn or blown in the motor manifold, it's gonna take more flow from the pump to make up for the lost oil in the closed loop. or am i brain dead tonight? it was a long day....... :drinkup
No worries chief, I was only suggesting something (that's a common Bobcat problem) to check. Sometimes it's hard for operators and folks to describe, put into words, exactly what a machine is doing. Just wanted to make sure we covered all possibilities.
yep i know what ya mean, i deal with it every day :salute :drinkup
There is Major creap from the left side. Main reason the mechanics said it was the pump was because when you drive it straight you actually have to pull back on the left side to go straight. They wear saying if there was a left moter problem you would have to give full power to the left side and pull back on the right. There is no power loss from the moter. I could still go cut dirt just fine. just have a bitch of a time driving it around.
Could you go in to more detail about this? is this somthing inside the pump? We took all the control linkage off and tried to ajust the creep. (using your creep adjustment write up) and got no where. Everything seems in working order.
if you have a creeping problem, fix that first. it may be the source of all your problems :drinkup
The "Repairing Creeping Bobcat" thread pretty much gives you the info you need to service the pintle arms Keller. The first 4 posts cover the two piece steel pintle arms, post 7 shows the one piece aluminum pintle arms. You shouldn't have to take the linkages loose to adjust pump drive neutral, but you should have the machine on suitable stands, wheels off the ground. If you've made certain that the drive centering components are in good order, and pintle arm is not loose where it clamps to pump control shaft, then your problem lies elsewhere.
There is no fixing this creaping problem. I see what the Pintle arms are now. These are not the problem. We have a major creep problem in both forward or reverse.(what ever direction you stopped last) it's so strong that is you try to hold machine still with parking brake, the brake will kill it. And when you sit there messing with it and find "neutral" then go in to forward it SLAMS in to forward like your dropping a clutch.
I think before you do anything, remove the hydraulic filter and cut it open. Look for metal inside the pleats, this will give you a rough idea what you are dealing with. If it is in fact a pump failure, you will have to replace the filter anyway. If you dont know the time it was last changed, maybe now is the time. It sounds more like a linkage/mechanical problem though than a hydraulic one.