I seems that the williamsburg 5395.700.20 toilet seat is no longer made. What can I use as a replacement

If you're using water out of the fresh water tank then the toilet gets water from the same water pump the sinks and shower does. If they work OK then there's an internal toilet part that has broken.

General Plumbing Supply has always come through for me...

Yelp only gives them a 3/5 but I have always had to wait with PROFESSIONALS to get my turn. I'm not big on ambiance when hunting for obscure plumbing parts..

BRING your old (always... any-parts) seat with you!

Amazon says $34 (plus tax)... Phenomenal return policy

A quick search on line yielded lots of other choices...

Happy hunting!

I had the same issue and basically called every single american standard distributor I could find. I finally found one! They had the gold hinges but I didnt care, it fits and works fine. Make sure you know the part number. I had a good salesperson that knew to look for any color hinge so I had a seat

I too have the same toilet seat that needs replaced. Porcher just told me there is NO replacement seat that can be used and they no longer make nor have stock of this toilet seat. I have a local company looking into the problem and will get back to me. For now I am going to take detailed measurements of hinge placement and length/width etc, and take a tape measure to every home imporvement store in the area. Anyone with any other suggestion would be greatly appreciated.

Well, something is amuck with the valve. What you do is jsut replace it. The plastic gets brittle, eventually.
There is also a chance that the shut off valve washer is causing issues. If the problem persists, look into that, also. The washer sometimes shrinks and will not remain open. It is an easy replacement fix.

Your toilet is still offered by the manufacturer:

http://www.americanstandard-us.com/toilets/williamsburg-one-piece-elongated-toilet/

Available replacement toilet seats from American Standard can be seen and ordered here:

http://www.americanstandard-us.com/repair-parts/toilet-seats/

You might consider finding you nearest dealer or choose another on-line retailer:

http://www.americanstandard-us.com/dealerLocator.aspx

Before ordering suggest you confirm with American Standard Customer Service the appropriate replacement seat for your model.

http://www.americanstandard-us.com/customerservice/onlineStoreSupport.aspx

I don't believe it is adjustable -- you'll probably need to replace it.

Hi. There are toilets designed to accept a round seat and there are other toilets designed to accept an elongated seat. The primary difference is that the round seat fits a round bowl and the elongated seat fits an elongated bowl.

I recommend that you return the elongated seat and exchange it for a round toilet seat. good luck