bought the bobcat not running. got it running damn good now. had a bad right rear tire. after getting the engine running i drove it to a different spot in the yard and the drive function sounded horrible but it moved. figured i do some general maintenece. change the engine oil and filter and also changed the hydraulic oil and filter. put 4 new tires on it. lift and tilt functions work great with no leaks or noises but the drive function doesnt work shortly after moving the controls. the skid wants to move after the first couple of seconds of moving the controls then no movement at all in all drive control positions. lift and tilt work fine during all of this. the manual doesnt mention a bleeding procedure so i assume its self bleeding.
bobcat 743 no drive function
- Thread starter busa4
- Start date
theres a larger hose that goes into the port block. http://i188.photobucket.com/albums/z125/haya262000/bobcat 743/th_IMG_0792.jpg?t=1287446031
http://i188.photobucket.com/albums/z125/haya262000/bobcat 743/th_IMG_0791.jpg?t=1287446031
epic fail at posting pics so ill have to post a link to pics. http://s188.photobucket.com/albums/z125/haya262000/bobcat 743/
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Ok, you have the older style. See the three hoses on the left? remove the middle hose and the big fitting, there should be a bronze filter behind it. Clean or replace it, your drive should return to normal.
Not many people know about this filter, so it gets neglected till it plugs up and causes drive issues. It will scream but not move, the pump will rapidly heat up too.
thanks a bunch. i know exactly which hose your talking about as i remember seeing that massive fitting connected to it. ill remove it tonight or tommorrow depending if i have a big enough wrench to remove that fitting.
just got around to remove the center hose filter. it was dirty but not clogged. i removed and cleaned it. reassembled. topped off hydraulic fluid and same problem. i jacked up the skid on all fours and moved the steer levers and the wheels turn but they dont have enough force to move the skid. with the wheels down the skid wants to move but once again after a few seconds, moving the controls has no effect. lift and tilt functions still work during all of this.
The lift/tilt is a seperate function of the drive. There are three pumps, two drive and one for the lift/tilt. Its possible your drive pump is worn too.
Can you try removing the filter and running it? see if it moves.
weres the pressure relief valves located? my manual shows them but doesnt state where there located. im going to check those first.
They are located in the centre piece of the pump. Look where the big hoses attach to, there will be two each side behind plugs.
so i started to remove the pump assembly. its loose but it will not slide forward. is there something holding the slip yoke onto the pump imput shaft? the manual says lift up and pull but no such luck.
You have removed the 4 bolts holding it in place? Two on the chain case two just under the fuel tank.
You really are better off removing the engine too, makes access easier.
The pump will simply slide out.
yes its definitely a tight fit. the 4 pump housing mounting bolts have been removed. i checked into it last night and there are two steel lines mounted on the back of the rear mounting plate. i think the hoses connected to these lines are hwat is holding me up. the drive coupler is a slip yoke style, correct? theres nothing holding it onto the pump input shaft?
The steel lines are fixed to the back plate, thats why you remove the two bolts that hold this plate to the frame (bolts are under the fuel tank), pull the entire thing out. Its really easier if you had pulled the engine too, you may find it hard to line everything up when re-installing the pump.
The connection from the pump tp engine is just a slip in style. Nothing locks it together.
thanks. finally got it out. i had to pry the pump forward. after 20 years the slip yoke was a little stuck. now off to the hydraulic shop for a rebuild. something tells me i should bring vaseline because im about to get f^%ked..
You caould do all the work your self, parts are pretty cheap. I did mine for about $1000 that was new rotating groups, wear plates, seal kit and bearings.thanks. finally got it out. i had to pry the pump forward. after 20 years the slip yoke was a little stuck. now off to the hydraulic shop for a rebuild. something tells me i should bring vaseline because im about to get f^%ked..
I hope the damage to yours isn't too bad.
where do i go to purchase a rebuild kit? i googled this to death but could only find a few places that would rebuild them at a heafty price of 1800.00
Contact these guys http://www.loaderpartssource.com/
Send me an email, there was one other place i may have info on still that had parts too. I'll just need to sift through old emails. Look up my profile, my email address is in there.
