Bobcat 731 - That 40 micron filter

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Indubyaonooo

New member
Joined
May 19, 2023
Messages
2
Any advice on getting the fitting that holds this thing hides behind broken loose would be greatly appreciated. Things I've tried......

  • Socket - Nut fitting so thin it just kept popping off. Tried putting a bar clamp on it but nothing to clamp to
  • Impact hammer - not nearly enough room
  • Thin 1 7/16 wrench - Fitting was rounding off
  • Screwdriver bfh method - Groove in the fitting but blow after solid angry blow failed to break it loose
The port block fittings on either side broke loose easily though I was only able to get one out of the way due to the fact one is a 90deg. Bought this thing at auction and rebuilt the engine (Deutz F2L511) myself. Engine runs great but machine seems sluggish with or without the lightweight over the tire tracks I put on it. Nothing in the manual about changing this filter even though it shows it in the hydraulics diagram
 

wateka

Well-known member
Joined
May 25, 2022
Messages
123
Assuming the 731 uses the same filter housing as an 853, the picture below shows your choices for taking it out/apart. Definitely change the Boss o-rings while you have it out.

IMG_1353.jpeg
 

cdmccul

Well-known member
Joined
Jun 18, 2013
Messages
504
Try a long pipewrench? They bita tighter the more you pull... The trick is to seat the fitting ALL THE WAY into the wrench. If you do that, then the fitting doesn't get deformed into an egg shape because the back of the wrench makes for 3 points of contact.
 
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Indubyaonooo

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Joined
May 19, 2023
Messages
2
@wateka...... have a big plastic box with hundreds of O rings if I could just manage to break it loose. Not much experience working on these things maybe that's part of the problem. Thanks for posting the pic. Gives me an idea what it will look like.

@cdmccul....... I haven't tried a pipe wrench. My biggest issue is that the fitting does look a lot like the thinnest one in the pic wateka posted. I'd guess that 20% of it is recessed back into the port block. A terrible design imo. The thing really hasn't been that bad to work on but this makes no sense to me at all. I'll give the pipe wrench a try thanks.
 

Tazza

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Dec 7, 2004
Messages
16,829
Have you tried heating it with a torch? no matter what, you need to get it out. Worst case, you will need to remove the port block from the pump then you can really go to town on it with a welder and a bigger hammer to get it out.

Glad you managed to rebuild the engine, they may be noisy, but they use no fuel and start even in the dead of winter.
 

cdmccul

Well-known member
Joined
Jun 18, 2013
Messages
504
@wateka...... have a big plastic box with hundreds of O rings if I could just manage to break it loose. Not much experience working on these things maybe that's part of the problem. Thanks for posting the pic. Gives me an idea what it will look like.

@cdmccul....... I haven't tried a pipe wrench. My biggest issue is that the fitting does look a lot like the thinnest one in the pic wateka posted. I'd guess that 20% of it is recessed back into the port block. A terrible design imo. The thing really hasn't been that bad to work on but this makes no sense to me at all. I'll give the pipe wrench a try thanks.

The big box of o rings I've noticed doesn't generally include the correct thickness of ring for boss o-ring seals. For the diameter you need, it will be too thick of cross section. You'll end up at a hydraulic shop or a good sized farm store to get the correct stuff. Most hardware stores I bet won't have it...it's not normal hardware. You'll have to loom in the Pioneer hydraulics section of a farm store.
 
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