bobcat 543 hydraulic gear pump

[LyHydroponics]

After sitting outside for a while, i decided to bring the bobcat in and pull it apart and repair the multitude of problems that ive had since i bought it. after searching the net for a while, i havent been able to find the specifications for the hydraulic gear pump. bobcatpartsonline.com lists the pump as 6598854.. However it looks as though the previous owner has replaced it with a Caproni pump.. This pump is in really bad shape and barely lifts a bucket of sand anymore. Does anyone have any details / specifications of what displacement, flow and pressure sized pump the bobcat needs? Current pump on it is a Caproni 20cg6.3x030G .. and from what I can tell it has 6.3cm3/rev 8.69L/min at 1500rpm and 250Bar pressure. In my shed I managed to find a spare Caproni 20C25x073g with 25cm3/rev 36L/min and 160Bar. Im fairly certain this would not be suitable right? But then again, I dont know what pump specs are meant to be on it.. Any help would be greatly appreciated!

 

[SkidRoe]

Assuming your machine is a 543, not a 543B, here is the pump that your machine is supposed to have: http://www.loaderpartssource.com/bobcat-parts/reman-bobcat-hydraulic-vane-pump-543.html The pump that you have in your shed is 4 times the size of the one you took off. The one that you took off sounds too small to me for your machine. For $450, I would spring for the correct pump. FWIW

 

[OldMachinist]

Assuming your machine is a 543, not a 543B, here is the pump that your machine is supposed to have: http://www.loaderpartssource.com/bobcat-parts/reman-bobcat-hydraulic-vane-pump-543.html The pump that you have in your shed is 4 times the size of the one you took off. The one that you took off sounds too small to me for your machine. For $450, I would spring for the correct pump. FWIW

Pump specs. from the service manual

 

[LyHydroponics]

Pump specs. from the service manual

Thanks OldMachinist for the info, it's exactly what i was looking for!
This is what i'm up against at the moment!

 

[Tazza]

Thanks OldMachinist for the info, it's exactly what i was looking for!
This is what i'm up against at the moment!

It looks like you have two pumps on the table, one in bits?

 

[LyHydroponics]

It looks like you have two pumps on the table, one in bits?

Hi Tazza, yes, I have the 2 hydraulic drive pumps and the gear pump on the table. I have since competely stripped down all pumps to inspect for damage and wear.. This is how I came to see the extensive damage inside the gear pump. According to Machinist's info, I think i might try and fit the gear pump i found in the shed into the bobcat.
There was also a very loud intermittent knocking noise coming from the pumps.. As it turns out the U-Joints connecting the engine to pumps was knocking around due to excessive wear from the splined yoke and adapter shaft..

 

[Tazza]

Hi Tazza, yes, I have the 2 hydraulic drive pumps and the gear pump on the table. I have since competely stripped down all pumps to inspect for damage and wear.. This is how I came to see the extensive damage inside the gear pump. According to Machinist's info, I think i might try and fit the gear pump i found in the shed into the bobcat.
There was also a very loud intermittent knocking noise coming from the pumps.. As it turns out the U-Joints connecting the engine to pumps was knocking around due to excessive wear from the splined yoke and adapter shaft..

Glad you found the U-joints were noisy, when they fail they fail in a bad way.
Depending on the gear pump damage, it may be ok. The problem is, when the bearings/bushings wear, the gears chew the housing out. New bearings bring it back, but you have excessive wear around the gears. They aren't very forgiving with wear. Vane pumps work quite well even when worn.

 

[LyHydroponics]

After a couple weeks of playing around with the 543, I've finally managed to get it to do what I want.. The left side drive motor is still a bit weak, but that will have to wait till next time..
Ended up stripping and cleaning down the hydro motors, replaced the old D950 with a D1105, and a lot of modifying..
http://img90.imageshack.us/img90/1980/imagelor.jpg
http://img819.imageshack.us/img819/3002/img2716w.jpg
http://img812.imageshack.us/img812/6774/img2743l.jpg
http://img593.imageshack.us/img593/2528/img2772oy.jpg

 

[Tazza]

After a couple weeks of playing around with the 543, I've finally managed to get it to do what I want.. The left side drive motor is still a bit weak, but that will have to wait till next time..
Ended up stripping and cleaning down the hydro motors, replaced the old D950 with a D1105, and a lot of modifying..
http://img90.imageshack.us/img90/1980/imagelor.jpg
http://img819.imageshack.us/img819/3002/img2716w.jpg
http://img812.imageshack.us/img812/6774/img2743l.jpg
http://img593.imageshack.us/img593/2528/img2772oy.jpg

Very fine job, i'm sure you'd notice the power difference now.
How long did it take you to get it all finished?

 

[LyHydroponics]

Very fine job, i'm sure you'd notice the power difference now.
How long did it take you to get it all finished?

Thanks Tazza, couldn't have done it without the help of the forum. It probably took me about a month to do. Mostly worked on it in my spare time. There is definitely a huge difference in power now. I had to adjust the pressure relief on the control valve because it was stalling the engine the first couple times.
The hardest part would have been making engine mounts and mating the engine to the hydro pumps. That took me 3 whole days to do. You may have noticed in the last pic that the radiator is sticking out the back.. I had to do away with the original fan and shrouds.
The oil cooler is still up in the top. Ive installed a small radiator fan and custom shrouds to draw air to cool it.

 

[Tazza]

Thanks Tazza, couldn't have done it without the help of the forum. It probably took me about a month to do. Mostly worked on it in my spare time. There is definitely a huge difference in power now. I had to adjust the pressure relief on the control valve because it was stalling the engine the first couple times.
The hardest part would have been making engine mounts and mating the engine to the hydro pumps. That took me 3 whole days to do. You may have noticed in the last pic that the radiator is sticking out the back.. I had to do away with the original fan and shrouds.
The oil cooler is still up in the top. Ive installed a small radiator fan and custom shrouds to draw air to cool it.

I did notice that, good job adjusting it to make it all fit. I have seen one or two machines on youtube that were butchered to make bigger engines fit, one had a V8 in it.

 

[pumphead]

When dealing with hydraulic systems and selecting the right pump for your specific needs, it's important to consider various factors to ensure optimal performance. In your situation with the Bobcat equipment, it seems you're looking to address issues related to the hydraulic gear pump.

The hydraulic pump plays a crucial role in providing power to the system, and its specifications need to align with the equipment's requirements. The original pump listed as 6598854 and the replaced Caproni pump, as you've mentioned, have different specifications.

From the data you've provided:

• The original Caproni pump is 20cg6.3x030G with 6.3cm3/rev displacement, 8.69L/min flow at 1500rpm, and 250Bar pressure.
• The spare Caproni pump is 20C25x073g with 25cm3/rev displacement, 36L/min flow, and 160Bar pressure.

When considering a replacement pump, it's important to match the specifications to the application requirements, which in this case include lifting heavy loads and ensuring precise control.

The spare pump you've found (20C25x073g) has a higher displacement and flow rate compared to the original pump. While the increased displacement might seem advantageous for heavy lifting, other factors like pressure rating and system compatibility should also be taken into account.

It's recommended to consult with hydraulic experts or Bobcat technicians to understand the original pump's specifications and the exact needs of your equipment. Given the complexities of hydraulic systems and their interactions, the choice of pump must align with the overall system design and performance requirements.

As for our product recommendation, considering the importance of high-performance pumps, I would like to introduce you to our PumpHead pumpheader.com . PumpHead(pumpheader.com) is a versatile high-pressure pump solution designed to deliver reliable and efficient performance. With customizable options and the ability to handle various flow and pressure demands, PumpHead could potentially be a suitable replacement for your equipment.

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Please remember that selecting the right pump is a critical decision, and seeking professional guidance is advisable to ensure the best performance for your Bobcat equipment.