What do I do to get it to fit back together. It expanded and won't fit the groove. Does anyone know any tricks. A new one is 100$.

 

Hot water is supposed to help keep it from expanding, don't know if it will shrink it, worth a shot.
Hope you don't have to buy a new one.

 

Just leave it sitting for an hour, it will shrink. Don't get carb/brake cleaner on it.




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Thanks dynobob. I let it sit over night. In the morning it fit perfectly.

 

Good to hear it worked for you.

I've used the HOT water trick several times. Works like a charm. It's odd, but HOT water shrinks and stiffens the diaphragm.

 

I'm guessing the formula of nitrile in the diaphragm is designed to work better warm than cold due to the environment it consistently operates in...behind a hot motor.

 

After cursing at an expanded diaphragm and the thought of a 100$ mistake, I calmed down when I read the hot water trick. I stuck it in a cup for about 15 minutes and then let it sit over night. It was back to normal in the morning.