New (to me) 743 Bobcat Maintenance Questions

Help Support SkidSteer Forum:

kadecole

Member
Joined
Jun 27, 2018
Messages
5
I have just acquired a 1990 model 743 Bobcat skid steer. Currently the machine has the hydraulic pump and engine removed. The hour meter reads just over 2000 hrs (if it was working still). I need to put the engine and hydraulic pump back into the machine. I was informed by previous owner that the hydraulic pump was just rebuilt/serviced and should be in good shape. The previous owner was having issues with the pump leaking and had the seals replaced and the pump serviced. The previous owner suspects the Universal Joint is bad and need to be replaced and was causing too much vibration, thus causing the pump to leak. I am looking for suggestions on what service/maintenance the engine might need before reinstalling. Should I inspect/replace the injectors? Should I inspect/replace the glow plugs? Should I inspect/replace something else? The previous owner said the entire unit ran fine before disassembly. Thanks for your help.
 

Tazza

Moderator
Staff member
Joined
Dec 7, 2004
Messages
16,829
Checking the universal joint is a good idea. Grease it up and make sure both of them are free to move around without binding. If they feel off, change them. When they let go, they can cause lots of damage.
If it ran well before pulling the pump and engine, i wouldn't really bother checking/replacing anything. Glow plugs and injectors are accessable with the engine in place. Not as good, but can be worked on if something is an issue.
If you were at all concerned. Get a pallet and ratchet strap the engine to it, Hook up a battery and fire it up and see if it starts and runs well, if it does, no need to do anything to it. Use a jug of fuel and prime it, give it a good 30 second glow then crank, see if it fires right up or not. If it does, you know you're all good. Just don't run it too long, as you aren't running coolant in it, you don't want to over heat it. 10 or so seconds is really all you need to know if it's running well or not, give it some throttle and shut off.
 

Tazza

Moderator
Staff member
Joined
Dec 7, 2004
Messages
16,829
Checking the universal joint is a good idea. Grease it up and make sure both of them are free to move around without binding. If they feel off, change them. When they let go, they can cause lots of damage.
If it ran well before pulling the pump and engine, i wouldn't really bother checking/replacing anything. Glow plugs and injectors are accessable with the engine in place. Not as good, but can be worked on if something is an issue.
If you were at all concerned. Get a pallet and ratchet strap the engine to it, Hook up a battery and fire it up and see if it starts and runs well, if it does, no need to do anything to it. Use a jug of fuel and prime it, give it a good 30 second glow then crank, see if it fires right up or not. If it does, you know you're all good. Just don't run it too long, as you aren't running coolant in it, you don't want to over heat it. 10 or so seconds is really all you need to know if it's running well or not, give it some throttle and shut off.
I forgot to mention, if you do fire it up, remove the universal joint and yoke first, if not, it will shake like mad!!!! as it will be really out of balance.
 

dabaines

Member
Joined
Jul 31, 2017
Messages
18
I forgot to mention, if you do fire it up, remove the universal joint and yoke first, if not, it will shake like mad!!!! as it will be really out of balance.
I would check the glow plugs. It's one of the first things I did when I bought my 743B. It was laboring when starting up. Turns out it had two bad plugs. I used the video linked below: https://youtu.be/n8N1PTQ_HJc Good luck with the new project!
 

Latest posts

Top