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hello everyone I have a john deere F525 with a fuel pump that won't pump fuel I have replaced all the fuel lines, the vacuum line and the fuel pump twice. I had bought and new fuel pump after I discovered it wasn't pumping and it still didn't work so I thought I got a faulty one so I bought another one and it worked when it wasn't connected to the carb so I hooked the lineup and then it would start so I removed the line again and it had stopped pumping, I put my finger on the vacuum line I can feel a lot of vacuum going through the line I also put a bottle full of gas on the line going into the fuel pump and it still didn't pump

Is there a regulator or something for the vacuum pressure

Please don’t be offended, but do you have it hooked up correctly? Post a picture of the pump and tell us which line you have attached where.

the black line going down is the vacuum and the black line going to the right goes to the fuel tank and the old white gray which is unrestricted goes to the carb

not all the clamps are on right now but were on during testing

Looks like it is hooked up correctly. If it works when it is not attached to the carb, but doesn’t when attached, I suspect the float needle in the carb is frozen closed, not allowing fuel to enter the float bowl. Time to check the carb.

Yep, it is hooked up correctly... My Mule uses that exact same pump. it's 19 years old and works fine.
is the vacuum line free of any splits or cracks? check that it's on good where it hooks to the block.

the vacuum line is new and the carburetter I just rebuilt the needle is not stuck it worked once when I first got it and never after that

when I was feeling the vacuum it seems like there is a lot of vacuum and it seems that it is vacuuming then blowing a bit so my theory is the crankcase valve is clogged up and all the air is going through the vacuum line which is why I had 3 pumps break does anyone know where the crankcase valve is

Engine model? Probably a Kawasaki...
On My Mule, it's a Kawasaki fe290, horizontal though, and there is just a hole drilled in the top of the block with a nipple fitting for the hose... There is also a small cast aluminum piece about 1/2" down from it that kind of boxes it in I guess to prevent oil from splashing up in it I guess. No valve of any kind
Of course your set up is probably 100% different.

If the fuel pump moves fuel when you disconnect the line from the carb, but not when you reattached the line, most likely probl is with the carb. That’s why I said you must check the float needle and seat. You said it working once and that was it. How did you verify the the needle is not stuck after it stopped working? Even the most experienced mechanics are not above redoing their work when they assume they did it right the first time.

Rivets said:

If the fuel pump moves fuel when you disconnect the line from the carb, but not when you reattached the line, most likely probl is with the carb. That’s why I said you must check the float needle and seat. You said it working once and that was it. How did you verify the the needle is not stuck after it stopped working? Even the most experienced mechanics are not above redoing their work when they assume they did it right the first time.

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Please read mine similar situation but no in warranty and 40 hr on a z535e Thank you Oaks

Very common for a little bit of the fuel line inner to break away when refitting and block off the fuel inlet at the carb
I usually hook up the fuel lines then remove the float bowl and see what is happening when the engine is cranked.