# fluval 304 not working need help!



## Jeff5614 (Dec 29, 2005)

The gasket fits in a groove on the motor housing. Without it in place I'd think you'd have a major leak on your hands. If there is no gasket on the motor housing and you don't have a leak then it makes me think there's no water in the canister or it's just partly full. Did you successfully prime it and are you sure it's full. Is the aquastop valve in the down position? If it's up then that valve is closed and you'll have no water flow in either direction.


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## truenoob (Apr 12, 2010)

Jeff5614 said:


> The gasket fits in a groove on the motor housing. Without it in place I'd think you'd have a major leak on your hands. If there is no gasket on the motor housing and you don't have a leak then it makes me think there's no water in the canister or it's just partly full. Did you successfully prime it and are you sure it's full. Is the aquastop valve in the down position? If it's up then that valve is closed and you'll have no water flow in either direction.



how do you prime it successfully? it is full and everything is in the on full blast position. i just figured out where that gasket goes. i thought it was something internal

im not even sure how to set this thing up. all i know is the propeller is acting very funny. it spins and stops and what not


btw jeff your tank is incredible. the one in the ink in your sig. and i want to do some piping for the filter like you did. is that possible for my filter? if i can get it to work


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## Jeff5614 (Dec 29, 2005)

Successfully primed for me is full of water and no leaks . Could it have an air pocket at the impeller? Rock it back and forth a few times and see if it blows out some air. The impeller shaft isn't broken is it? 

Yes, you can plumb a few things inline with your filter but it will reduce the flow somewhat. It's not too hard.

If it were me, I'd call the friend I got it from and have him come over and help me set it up.


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## truenoob (Apr 12, 2010)

Jeff5614 said:


> Successfully primed for me is full of water and no leaks . Could it have an air pocket at the impeller? Rock it back and forth a few times and see if it blows out some air. The impeller shaft isn't broken is it?
> 
> Yes, you can plumb a few things inline with your filter but it will reduce the flow somewhat. It's not too hard.
> 
> If it were me, I'd call the friend I got it from and have him come over and help me set it up.


he lives way too far now. i just noticed that it is leaking from the head.


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## trap (Apr 10, 2010)

I've had this problem getting mine to prime too. It helped me to have the return side slightly above water line while priming. This way air will escape from the cannister easier thereby fully filling the cannister with water. You need to be carefule to keep the return side positioned so that when the prime is complete it will spill water "inside" the tank. Hope that makes sense.

The return creates an air lock if it is below water line.


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## truenoob (Apr 12, 2010)

what do i do about water leaking from the head!?????!!!


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## trap (Apr 10, 2010)

If your gasket is in good shape you shouldn't have trouble with leaks. You could try removing the filter from under the tank, open it up, make sure no foreign stuff is between gasket and cannister body. pre-wet the gasket before putting the head back on helps to "slip" into place. I always "seat" mine fully before closing the locks on the side. I don't use the locks to pull the head into place, but that's just me.


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## sajata (Aug 21, 2009)

have you checked for dirt or substrate in the well where the impeller goes?
not the leak problem but the noise problem...


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## TeamTeal (Mar 31, 2010)

shoot water into the intake with a powerhead to get it started, if there is not enough suction at first. 

if you filter is leaking, then you have other problems to worry about


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## trap (Apr 10, 2010)

On mine, the impeller will make noise if there is insufficient water, it's normal, but do not let it set and run without enough water. It might damage something.


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## stingraysrule (Apr 4, 2010)

The rubber band fits on the top of the canister. Open it up and turn it over. 
The propeller thing will be facing you. 
Fit the band in the groove where it kind of seals it together. 
The propeller is not turning correctly because
1. It is not fitting correctly in there. 
2. The pin holding everything together is busted, or.....
3. It is not primed right. 
The easiest way to prime it is.. 
Keep it unplugged. 
connect the hoses to the top part of the machine. 
Push the FIRST lever down. 
Put the output hose in the tank. 
Take the input hose and fill it with water while it is attached to the cannister. when the water hits the top of the intake tube, slowly lower it into the tank as so the water stays in the tube. 
Plug the machine in. 
Slowly pull the second lever down. 
If it does not catch, pump the machine with the primer pin. 
It should blow water and air thru the outake hose. 
If the propeller is still making that grinding noise, then the inside guts might need to be replaced. 
That propeller should pull out, along with the guts of it. It is magnatized 
so you might need to get something to grab it out of there with. 
New guts = $14.00


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## truenoob (Apr 12, 2010)

all good suggestions, ill give them all a shot but i cant seem to get the head to stop leaking. the gasket looks fine...


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## trap (Apr 10, 2010)

There's just got to be something between the gasket and the head, or something on the housing body, preventing a good seal. Have you tried slipping the gasket off and checking that nothing is under the gasket? I had a similar thing happen to mine a couple years ago and once it had a clean mating surface it was fine.

Last resort would be a new gasket... I've had my 304 for years and never needed a new gasket, though


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## alan j t (Feb 13, 2008)

first, i would start with using vasaline on the gaset/ o-ring.
if it still leaks try closing it by pushing the head down first before locking. or buy a new gasket
second, there should be a ceramic shaft in the middle of your impeller, make sure its not broke.
then after all is closed and sealed, prime that sucker!

i own 3 fluvals and have had very simililar problems.


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## truenoob (Apr 12, 2010)

ordered new o ring. it leaks like crazy. wierd art is... O ring looks fine


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## alan j t (Feb 13, 2008)

ya, they will look fine,i've ordered o rings before too.
i bought a used fluval on craigslist just for parts.


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## stingraysrule (Apr 4, 2010)

I seem to notice that if it is leaking a little.... put a towel under the canister and wait it out an hour or so. The canister starts to "suction" itself, and it stops leaking. 

I have 5 fluvals running right now. 
204, 205, 305, 305, and a 405. 

I also have an extra 204 for parts.


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## truenoob (Apr 12, 2010)

its leaking quite a bit. i just put the new gasket in and it still leaks!. i leak test it by running sink water through the IN side and leave it on low so it does not leak from the Out part. it leaks alllll around the head! HELLPPPP PLEAASEE!!


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## Beeya (Mar 29, 2010)

Try greasing it up a bit with some silicone grease. You can get it at lowe's or HD, will come in a little tub like this http://www.nothingbuthardware.com/450383.html.

When the gasket is in the well properly and lubricated, the motorhead should slide onto the media canister easily without too much force. With my 405 I only need to press down a little to seat it. I've found that if I don't grease the gasket the motorhead won't seat properly and leaks are inevitable.


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## truenoob (Apr 12, 2010)

Beeya said:


> Try greasing it up a bit with some silicone grease. You can get it at lowe's or HD, will come in a little tub like this http://www.nothingbuthardware.com/450383.html.
> 
> When the gasket is in the well properly and lubricated, the motorhead should slide onto the media canister easily without too much force. With my 405 I only need to press down a little to seat it. I've found that if I don't grease the gasket the motorhead won't seat properly and leaks are inevitable.


the gasket came all greased up from fluval. shouldnt it work without all that headache. does everyone use silicone grease on it. doesnt that make it hard to open back up? i dont have media in it yet i dont plan to invest in the media if i cant get it to stop leaking


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## Beeya (Mar 29, 2010)

truenoob said:


> doesnt that make it hard to open back up?


Silicone grease is a lubricant, not a sealant.


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## truenoob (Apr 12, 2010)

i just greased it up. put it back together and it leaks just as it used to.... maybe the handles are no good?


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## alan j t (Feb 13, 2008)

can you post pic just for reference?

its not leaking from the quick realease hose stuff right?


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## trap (Apr 10, 2010)

You know.... I looked at mine (not hooked up presently) and there is a slot inside the part where you connect the hoses. The slot is where the "out" tube goes. If you lift up both the levers and remove the plastic connection you can see the slot inside there. I am wondering if you possibly had a bad o ring on the "in" or "out" tube, would the slot allow it to leak to the ouside of the cannister? I don't know the answer but maybe this is the cause since you have a new main gasket with still leaking?

Look at it and see. I think it's possible that the new gasket works fine but the o ring on the out tube could allow water to enter the head above the main seal.


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## discusonly (Mar 28, 2010)

It could be the handle or the cannister itself. I went through something like this a few years back. Ended up getting a new cannister. Total cost of all the replacement parts I went through was about the same cost for a new one.

Before ordering more parts, I suggest taking it apart. clean and lube all the seals. Sometimes it's better to move on to the next filter.


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## brianS (Apr 22, 2010)

Too bad it's a 304. I wonder if the 304 & 305 is compatible? I have (3) 305's...well, (2) of them that are just sitting around that I'd be happy to give up, but they both need a impeller cover & shaft.


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## alan j t (Feb 13, 2008)

most parts are compatible with the 04 n 05 series.


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## stingraysrule (Apr 4, 2010)

Are you sure you are putting that gasket in the right groove? 

Once, I took mine off and was not sure where to put it back.


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## FSM (Jan 13, 2009)

clean the groove that the gasket sits in.


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## truenoob (Apr 12, 2010)

discusonly said:


> It could be the handle or the cannister itself. I went through something like this a few years back. Ended up getting a new cannister. Total cost of all the replacement parts I went through was about the same cost for a new one.
> 
> Before ordering more parts, I suggest taking it apart. clean and lube all the seals. Sometimes it's better to move on to the next filter.


i did everything everyone suggested. and im sure i ut the O ring in the right spot. no luck...no luck t all. im actually incredibly sad and i guess its just not going to work. i do not know why....


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## truenoob (Apr 12, 2010)

alan j t said:


> can you post pic just for reference?
> 
> its not leaking from the quick realease hose stuff right?


ill post a pic up as soon as i can. its not leaking from the in or out of the hose. just the head itself, all over.ill actually make a video


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## Braduin (Apr 6, 2012)

*Same Thing*

I had all the exact same problems. I eventually fixed the filter and it is amazing!!! So first i will start off with the motor problem. The motor is spinning and then falling about a cm and getting stuck on a ledge. so it almost needs a spacer. I just stuck a k'nex piece on the little stick poking out of the motor. Its a little blue one called an axle spacer (i tried to attach a pic). (Google it) as soon as i did this the motor worked perfectly. I had some leakage problems too. I got this grease stuff from the pet store and spread it all over it. then i clamped the filter shut. It will drip and run quite a bit, for a few seconds, then the suction will prevent any leakage at all. Hope it helps!!!


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## Rainbowfishman (Jun 19, 2018)

Is the white plastic shaft that the magnet / impeller suppose come out or did I break it?


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