Hello everyone, I'm new to this forum and new to owning a skid steer. I apologize for my ignorance and really appreciate any assistance. I have operated a few Bobcats, Case 1840s and 1845s on occasion but only for a few days at a time. I bought an extremely used 2001 Case 75XT with 6300 hrs that needs some TLC. I have made several repairs and I think I am well on the way to making it reliable. I have not found an operator manual and have a few questions about operation and controls. I do have a service manual and the parts list. There is a small lever behind the right side control joystick that I haven't figured out, I don't see anything happen when I move it. It is connected to the right side control valve assembly. There is a cold start assist rocker switch on the right side dash, does it operated a heater grid or some other method? I'm not sure its functioning because it seems slow to start with or without it. This machine has a rocker switch that operates the AUX hydraulics, how do you "lock" the hydraulics on for use with a backhoe or trencher attachment? There is a black button on the left joystick, I think it is supposed to be the parking brake and a red button on the right joystick which I think is the horn. Neither seem to do anything, are my assumptions on their functions correct? The engine is new and sounds perfect when running and seems to have plenty of power but it is slow to start even at 50 degree temps. I am planning to change fuel hoses, filters, and lift pump and flush the fuel tank, what else should I be looking for? Is there an easy way to check injection timing? This has a CASE 4-390 which is a Cummins 4B-3.9 Thanks in advance for your help.
PS, Does anyone have a good source for "Case Power Tan" paint? Thanks again
It depends on which fuel system is on your engine as to how easy it is to check/set the inj. pump timing.. If its a CAV/Delphi rotary pump, there is a plastic push in button under the pump.. If its a Bosch inline pump, that's alittle different.. Pictures would help & would keep you/us from wearing your fingers out typing.. Also, pics of the intake, to tell you if it has an intake heater grid..
Thanks It has an Inline pump, I believe it is a Bosch but not sure yet, currently the machine is at another location. I will have it at my shop on Friday. I will post additional pictures at that time. Did these come with glow plugs and an intake heater or just the heater grid?
Gonna be 1 or the other..
The small lever might be to lower the boom if the machine dies with the boom up. To find out raise the boom kill the machine pull the lever back and try to lower the boom. Just be careful.
-Yes, the little lever is to lower bucket if engine dies, just move it and operate boom lever. - the "preheat" rocker switch operates a device called a "thermostart", I took mine out to test it because I too could not tell if it was working, I put it in the vice with the fuel line pointed up and a dribble of fuel in it and put power (12v) to it and a coil lights up and a few seconds after a little valve opens up and drips fuel on coil, causing a small fire. It is located in intake manifold. - On my 90xt, left joystick buttons: red is park brake, black is 2 speed. - to lock my aux hydraulics on mine, it is a rocker pedal in between your feet, it has a lever to lock it down. - mine has rocker switches on joy sticks too but it seems they do nothing as machine did not come with all the options? Thats what it looks like to me.
Thanks for the replies, I will give the lever a try when I get the machine to my shop, that didn't occur to me. The thermostart is an interesting concept, I will have to pull it just to examine and test it. I believe I have a weak lift pump so that would explain it not making a difference if it's not getting fuel. My Aux hydraulics operate from a rocker switch, the peddle would be similar to the 1840s and 1845s that I have operated in the past. I don't see an obvious way to lock the switch. I will keep trying. I will post pics of the controls, injection pump, and intake piping as soon as I can get them. Thanks SO much for the assistance, LOVING the forum so far.
IF its an inline pump.. I'll know for sure when I see the pictures..they have an overflow valve on the return line, at the pump.. Its a spring loaded banjo bolt style valve, that hold the pressure from the supply pump, in the fuel gallery of the pump and "pops off" when the pressure exceeds 25-30psi.. So you say you think you have a weak lift pump?? they're cheap enough to replace AND DO go bad, all the time.. BUT it might just be that overflow valve that's causing your hard start problem..?? They aren't real cheap, so you might want to rig up some gauges to check the output pressure on the lift pump and the output pressure on the return.. Just a little heads up for what your instore for..
Thanks, that's good to know. What should the pressure be from the lift pump to the injection pump? I am planning to add an electric pump at the level of the bottom of the tank and have it feed a new OEM lift pump. The pump I plan to use is a 130 GPH at 14 PSI adjustable, will that be sufficient? I have access to gauges and fittings with no problem. Just need to know what it should be.
If you going to keep or replace the stock lift pump w/ a new one and use the electric as a helper pump from the tank TO the lift pump.. 14psi is plenty.. maybe too much.. the last thing you wanna do is blow out the stock pump.. and fill the crank case w/ fuel.. 3-5-7psi is about the max I'd go as a "pusher/helper pump".. If you were going to bypass the stock pump, 25-35psi would feed the injection pump..
Great, Thank you
That's a Bosch VE pump.. No easy way to check the timing.. ya gotta have an adaptor & dial indicator to screw into the back of the pump to check the plunger lift.. when the pin under the pump locks into the cam gear... you CAN get them on ebay for around 30.00.. along w/ the engine turning tool for another 30.00
As you can see from the pictures it is not an inline pump. I also do not see any sort of cold start assist, can I add a thermostart to it?
I honestly dont know what that gizmo is on the intake pipe.. hopefully someone will chime in..
My 90xt has the thermostart in that flat-faced hump on your intake manifold, right below that lower gear clamp, it appears your does not have one, there is an approx 7/8" headed hole that it screws into.
@thepumpguysc The gizmo on the intake is the air filter restriction indicator switch. If these engines wind over too slowly while cranking, they will be hard to start. A good battery & healthy starter motor is required. Make sure the ground at the battery & the other end of the cable are thoroughly cleaned. @atvfan2000 What is that fluid in the belly pan? water? fuel?
That makes sense alrman.. I'm used to seeing the push button ones w/ the green, yellow, red scale.. Thanks..
It is water, it has been raining all day and the machine was sitting on the trailer for.most of it.
Does this pump have a relief valve at the return line location as mentioned above?
This machine has a rocker switch on the right joystick which operates the aux hydraulics, I found a peddle to operates the aux hydraulics also. It has been removed from its normal location and was laying under the floor pan. My next dumb question is where is it supposed to mount? I haven't found any matching holes. Thanks
It does not have a "pressure type" overflow valve.. its an orifice.. that bleeds fuel & air.. no adjustment.
Mine pivots on a bolt that goes thru the "wall" at your toes under the door (when you are sitting in it, obs)
Does anyone know what this does? It is mounted to the bottom of the injection pump and has a wiring harness connected to it.
That's the "cold start" advance mechanism.. it either advances or retards the timing for cold start ups.. I seriously doubt its bad. Some have 12v all the time, while others have 12v until warmed up.. easy check w/ a meter.. Its NOT like a regular solenoid.. its a wax motor w/ a rod in it.. whatever you do, DO NOT pull the rod out of it.. The wax heats up & pushes the rod out, to uncover a port to advance or retard the timing.. When it cools down, the wax rehardens and covers the port back up, ready for the next cold start.. If your going to remove it to SEE if its working.. it takes a LONG TIME to move.. 12v to the spade, neg. to the body & wait for the rod to start moving.. once you SEE it start to move STOP.. and remove the voltage..
How long should it take to "activate", how long should I wait before cranking? Should I hold the thermostart button to make it work or does it work off of engine temp?
You'll have to use a meter to check it.. "normally" you wouldn't have to do anything.. it works off air & water temp..