I replaced the diaphragm gasket and when I bump the filter some DE still shoots out into the pool. all the tube sheet hex screws are all tight. Paul

see what is on the side of the pump motor it will tell what voltages are to be used if able to use 240 volts you will save money on your electric bill if it has a 120 volt plug on it you have to run at 120 volts

If you have DE leaking in through the return lines, there are a couple of things that you should check. You probably having an opening or tear in one or more of your flex tubes. If that is the case, you will need to replace the damage tubes and the problem should be corrected. There could also be a rip or tear in the pool filters diaphragm gasket or it could be worn or loose. If you notice a problem with the diaphragm gasket, replace it. You could also have loose bolts on the tube nest plate. Try tightening these bolts.

No, you should not have to use cement to install the diaphragm gasket on these particular pool filters. Here is a copy of the owners manual for this model. It has a diagram of construction in case you need it to figure out how to get the replacement part on the filter.

If these Hayward pool filters are leaking DE back into the pool, there are a couple things that you will want to check. Check for loose bolts on tube nest plates and tighten them if necessary. Make sure that you don't have a worn or loose fitting diaphragm gasket and that there are no rips and holes in it. Replace the gasket if any of these is the problem. Check for openings or tears in one or more Flex-
Tubes and replace them if necessary.

If D.E. is returning to the pool, it's usually because you have a tear in the grids or the backwash valve is not working properly and returning D.E. back to the pool.

Try bumping the filter. You might have D.E. coated with normal accumulation of pool dirt, algae, etc. Your pool filters pump strainer or skimmer baskets could be clogged. Make sure there are no obstructions in your impeller. Finally, check the cover gasket, hand knobs, hose, clamps, etc. Replace or tighten as necessary.

It could be one of these issues with your pool filter. Try these solutions. If none of them work, let me know and I will do some more research.

1. D.E. coated with normal accumulation of pool dirt, algae, etc.
Solution: Bump your filter.

2. Pump strainer basket or skimmer basket is clogged.
Solution: Clean

3. Pump impeller vanes clogged.
Solution: Cleaning with a stiff wire brush through the pump strainer opening will usually work. Alternate method would be to disassemble and clean.

4. Air Leak on suction side of pump.
Soultion: Check cover gasket, hand knobs, hose, clamps, etc. Replace or tighten as necessary.

5.

A better way to clean the filter tubes in the EC40 is to remove the filter tube assembly and soak it in a 5 gallon paint pail that is filled with a solution of water and a 20% muriatic acid, available at hardware and home center stores. Be very careful handling the muriatic acid. Don't splash it around.

Mix it in a 1-to-1 ratio with water and soak the assembly for at least 8 hours. Keep the soaking pail out of the reach of kids and animals.

Remove the assembly, properly dispose of the acid mix and refill the pail with clean water. Soak again for 3 to 4 hours, then reassemble your filter.

Some pool guys say it isn't necessary to soak the tubes in clean water because the muriatic acid will not harm the pool water and will reduce the pH if it's too high. I've always soaked them to be safe.

This is a link to the Hayward manual that describes the process:
www.haywardnet.com/products/Manuals/pdfs/manual9.pdf

make sure the gasket around the tube sheets is secure

Most likely the "fingers" inside the filter housing are worn out and causing the DE to blow out the return line to the pool.