Bobcat 743 b

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Iguana

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Entire unit? The alu casing and filter itself or am i missing something? Can it be cleaned or not really? First time doing it...
 

brdgbldr

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Entire unit? The alu casing and filter itself or am i missing something? Can it be cleaned or not really? First time doing it...
The entire unit Housing and all. These are used on all sorts of machines. A lot of the time you can hit a tractor store for them. Bobcat wants like $58 for them but check around. Also, there is an o-ring at both ends where the hoses/fittings go in that may need to be replaced.

They are serviceable but a pain in the butt and you may find other parts bad in it. Not worth my time to mess around with. I would suggest buying a new one and after replacing the old one you can play with the old one and see if you can service it. If it works out, the next time you need to change it, you can just keep swapping them.

Here is an exploded view of one:
 

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Iguana

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Thank you very much will do . It hasent been replaced in the last 20 years so not sure what i will find when doing that in the next week or so. Wonder if that could be the cause of the whine on my hydraulics. Anxious to get to it but work is crazy at the moment. Appreciate the help
 

dfb

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While standing behind the machine viewing it from the rear, the hoses on my 742B leave the engine compartment through an oval hole with a grommet whose center is 8" to the left of the RH cab hinge. The hole entering the cab is directly above that location. The kit was already installed when I got the machine. I can provide pics or more detail if you need them, I don't know how to post pics here. HTH.
 

Markle

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Iguana that looks like a standard bobcat case drain filter housing. Let us know what grunge and particulate might be inside. Thanks for the followup.
 
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Iguana

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Hi Markle
Will do hope to get back there over the week end. Has never been replaced so must be blocked. Do you think that will fix my whining noise? Anxious to find out. Thanx for the help
 

dfb

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Seeing what it has captured gives a good idea of what is floating around in the hydraulic system.
 

Markle

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My intuition is that the noise may not dissipate even with a new bronze filter installed. Metal pieces and black particulate may reflect deteriorating seals in the hydrostatic motors, or excessive wear. Peace of mind is certain with a new filter installed, since you stated that you have no adverse symptoms affecting machine function, just noise.
 
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Iguana

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Dont know if its good or bad news...
 

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dfb

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My machine had 3200 hours on it when I got it and seriously doubt anybody had ever looked at it. After rebuilding the first drive motor which failed is when I replaced it and inspected the old one. It had much more stuff that that one does. IMHO you are in good shape with that but as has been stated previously, doubt it will affect noise.
 
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Iguana

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And by rebuilding the 2 drive motors? Would that help even? Or am i worryi g about nothimg. Awesime old machine would lime it to be in tip top shape
 

Markle

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Iguana, that does not appear to be excessive and I agree with dfb.
maybe slight deterioration of seals but not alarming. I don’t see metal flake. Run it;use it…and keep routine maintenance on hydraulic fluid and filter….in my humble opinion.
 
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Iguana

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No did not make a difference. Tried to listen from where the noise originates and guessing its the drive motors. Playing with the idea of taking them out and sending them in but not sure if its going to be worth it... Previous owner ran it on hydraulic oil in stead of 15w30. Could that ve done damage and to what?
 

Markle

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Original bobcat spec for 743 for oil in the hydraulic hydrostatic system was 10w30 or 40. Bobcat dealers say now use their modern hyd/hst fluid. So I doubt any perceived motor drive issues would be due to the fluid differences.
 

dfb

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After rebuilding both my drive motors and fixing all the leaks, I drained and refilled my system with the Bobcat fluid for the piece of mind. It was wisely explained to me that hydraulic fluid lacks the lubricity necessary in a hydrostatic system. My machine drive and hydraulic systems operate smoothly warm or in bitter cold. Absolutely no regrets using the bobcat fluid even if it might have cost a bit more.
 

Dr.SidewayZ

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Jan 11, 2023
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And by rebuilding the 2 drive motors? Would that help even? Or am i worryi g about nothimg. Awesime old machine would lime it to be in tip top shape
Doing the drive motors helped a lot here’s some diy videos I put together for doing them, replace the brass filters as you won’t be able to clean them as once debris is in them you won’t be able to get it out

Hey guys I’m new here and I make Tutorial videos on YouTube for our bobcats mostly 743b and similar variants. Here are a couple examples of videos that I’ve done.
How To Set Bobcat Creep in LESS Than 8 MINUTES

Bobcat Steering Bushings Replacement: A Step-by-Step Guide

How to rebuild Bobcat drive motor for less then $100

Just a couple examples hopefully someone finds some use for them and hopefully it helps someone out! I look forward to being on here more often and helping out in any way I can. Hope y’all have a good evening and rest of your week

-Mike
 

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