763 pump replacement-anyone done this?

[linrick1]

Hi all, A friend of mine has a 763 F series Bobcat with 4000+ hours on it and it sounds to me like the pumps are about shot. It has started to make an awful howling/knock sound with loss of power at the drive and lift, which gets worse as it warms up. My assumption is the pumps are in need of replacement and am wondering if anyone here has any experience with changing them out. Thanks, Rick

 

[linrick1]

Well, since nobody seems to have done this type of repair I will try and show how I am going to go about getting the pumps out of a 763....first order of business was cleaning 10 years of s&%@ out of the drive/pump and engine compartments.....nasty. Next is going to be moving the machine up to the shop itself which is going to be interesting because now it will not move at all under its own power. How are you supposed to tow one of these without tearing anything up?

 

[SSdoxie]

Towing the machine, letting motors rotate without oil, can cause damage to the motors is they are not already damaged along with the pumps. If you need to tow don't go very far or very fast. To tow it, use 2 wires with alligator clips at the battery, unplug the brake solenoid and hot wire the solenoid with battery voltage. Then use bungie cords to tie the steering levers to full stroke in the direction you are moving.

Regarding your 1st post: The engine and pump unit are installed as 1 package, fastened to the frame on 4 mounts (1 at each corner). If you can get the pump drive pulley off while in the machine you can remove the pump and leave the engine in. On a 763 there is not alot of clearance from the end of the pulley to the frame if you need a puller to get the pulley off but may be worth a try before taking engine and pump unit out.

 

[HarryN]

Sorry I have no advice, but I do have a 1999 763 F as well. Looking forward to your pictures and how you proceed. Are you planning to replace or rebuild them?
By the way, the cleaning sure made a difference!

 

[linrick1]

Thanks for the interest and information. It would appear that I (fortunately) mis-diagnosed the pump as the problem...it turns out it was the tensioner that was shot, so $400.00 plus later new one is in and she runs mint. While I'm at it I'm rebuilding/repairing the heater and the hand controls, rear door hinges, etc., etc.. should have the rest of the parts I need by Friday so I'll give it good workout then - that'll tell me if it was the tensioner or the pump for sure.....here's the offending tensioner and the new one installed. Rick

P.S. There is no way I was gonna work on that thing the way it was....took me 4+ hours to pressure wash it...got like a quarter yard of s#%@ out of the chassis......

 

[HarryN]

Well that's good news.
I had similar problem. The tensioner has an arrow on the spring. Mine was pointing to 12:00. As you tension the pulley, the correct tension would be when the arrow points to 3:00.
That solved a squeely belt that was slipping and causing the hydraulics to seem like they were weak!

 

[anthony p]

i have a 763 bobcat it seems like it has no power it will barley go up on the trailer ... i ran it low on fuel and low on hydr fluid no it barly moves... i changed the hydr filter and i put fluid in it it said on the can hydrand transmission fluidplease help me i dont know what else the do

 

[anthony p]

bobct 763 has no power the move very week
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i have a 763 bobcat it seems like it has no power it will barley go up on the trailer ... i ran it low on fuel and low on hydraulic fluid 2 gals low no it barly moves... i changed thehydraulic filter and i put fluid in it it said on the can hydraulic and transmission fluidplease help me i dont know what else the do
04-10-2012 10:29 PM

 

[SSdoxie]

bobct 763 has no power the move very week
--------------------------------------------------------------------------------
i have a 763 bobcat it seems like it has no power it will barley go up on the trailer ... i ran it low on fuel and low on hydraulic fluid 2 gals low no it barly moves... i changed thehydraulic filter and i put fluid in it it said on the can hydraulic and transmission fluidplease help me i dont know what else the do
04-10-2012 10:29 PM

As stated above double check the drive belt tension, condition of the belt and the tensioner. Drive belt can slip without making any noticeable squealing noise.

 

[anthony p]

i have tighting the belt. i called the dealer and they said its the fluid i have the flush the hydr fluid. i went to tractor supply and bought hydr and transmission fluid and put it in my bobcat and by the end of the day it strated having the problom i plan the drain it out and buy and nother fluid and see what happens what do you think of r&o hydr fluid