Bobcat 743 b

[Iguana]

Hi giuys
Mew member here and need your help. My 743 makes a wining noise when pushing dirt or turning. Got enough power just noisy! Replaced oil and filters but no luck. No noise when lifting.
Any ideas?
Regards
Iguana

 

[brdgbldr]

Hard to diagnose a noise on here.

I have found that the wining noise when engaging the drive motors is from the relief valve. You may have an in-line brass filter that is clogged.

 

[Iguana]

Thanx a million! As a newbie to the machine where will i find the brass filter? Will download the manual too to help. if you would be so kind just to point me in the right direction to start my search?

 

[brdgbldr]

Go to the Bobcat Parts Catalog: https://www.bobcatpartsonline.com/#/catalogBrowser

Enter your serial number and then do a search for filter. This will bring up all of the exploded views of the parts catalog with filters in them.

The brass filter is normally in-line and is encased in an aluminum housing. They can be taken apart and cleaned, but I find buying a complete new one a better option since there are o-rings involved and sometimes the aluminum housing is a pain to get apart.

 

[Iguana]

Thank you very very much! Will check it out and let you know
Regarfs
Iguana
South Afr

 

[Iguana]

Oh dear get an error message when i click on the above link. If you dont mind can i send you the serial nr in a day or 2 to see if you ve better luck?

 

[brdgbldr]

You can also search by model number by clicking on the Model Number tab and then choose the serial number range that fits your machine

I can try if you send me your serial number.

 

[oiu789]

Let us know you what you find!!

 

[Markle]

On my 743, the sintered bronze filter is in the port block mounted on top of the hydraulic pump, first thing you see when lifting the cab. The port block is square(ish) and has three large hydr hoses going into the right side ( seated driver's right). The filter is in the middle port.

 

[Iguana]

Hi guys
Thanx so much will have a look and report back. Will only be over the week end as work is getting crazy busy before December holidays. Hoping to have the skid sorted as the noise is hectic on the ears!

 

[brdgbldr]

Hi guys
Thanx so much will have a look and report back. Will only be over the week end as work is getting crazy busy before December holidays. Hoping to have the skid sorted as the noise is hectic on the ears!

This may seem silly, but I have done stranger things myself….

Is your brake engaged? A lot of new owners with old machines do not realize that the center pedal is a brake. Most of the older machines brakes are worn out or not adjusted properly. A lot of users do not use the brake at all. So, inadvertently, the brake could be engaged which would cause a high squeal when engaging the drive motors due to the pressure relief valve opening.

Also the brake could be stuck on.

 

[jp8775]

On my 743, the sintered bronze filter is in the port block mounted on top of the hydraulic pump, first thing you see when lifting the cab. The port block is square(ish) and has three large hydr hoses going into the right side ( seated driver's right). The filter is in the middle port.

Can you out up a picture of your block? I do not see one on my 743B

 

[Iguana]

Hi guys
My parking brake sort of works and have tried engaging it and releasing it and jip it works enough that i can feel a difference in its performance. I have received the serial nr if someone would be so kind to check if it indeed does have a filter?
S/n 509 320 459
Thanx for all the replies and help much appreciated

 

[Iguana]

Will post a pic for sure as soon as i get back to my yard. Parking brake stuck... making me think... just strange that it moans only under load like turning and pushing...
Great forum thanx guys covering all the possibilities!

 

[Markle]

im not able to open up the cab right now, but here's a pic from the parts online…yellow hi light is the port block. Red arrow points to the bronze filter. In this diagram, front of machine is Northeast.

 

[Markle]

Here is a pic from mine. Front of machine is at bottom of pic. Cab is lifted of course. Red arrow shows the fitting which houses my port block bronze filter. Remove that hose first. Then remove the hose fitting from the port block. There's a spring, o ring, and bronze filter. Filter kit bobcat #6563995. Again…this is for my early sn 743.

 

[Iguana]

Only pics i could find really really old ones. Will get better ones soon

 

[Markle]

You definitely do not have a port block mounted on the hyd/hst pump. I looked at the parts diagrams for later sn 743s online, and the ones that do not have the port block on top of the pump appear not to have this bronze filter. So we might be chasing something that doesn't exist on your machine. This rabbit hole started from a noise concern. My 743 groans when moving, equally both sides, with no decrement in power or ability. I mentioned it recently to a hydraulic expert and he said these hydrostatic motors in the 743s made more noise than later series bobcats. So with no adverse symptoms, I use mine and don't worry.

 

[Iguana]

Markle thanx a million suppose we must just run it and stop worrying. Like the saying goes if it aint broke...
Thanx for all the help

 

[Iguana]

Guys good morning! Just to follow up on my post i think i found my brass filter!