Problem flushing - testing drain

[Jechow]

I have two builder toilets from the 1980's that constantly need double flushing. One of the toilet needs double flushing even for liquid waste.

I'm going to replace the toilets with Toto's but I was thinking that I would test the drains before getting and installing new toilets. Can I do this test with the existing toilets still in place? I was thinking of taking a garden hose and running the water into the bowl.

Thanks

 

[Reach4]

That works. Another test would be to pour 4+ gallons of water from a 5 gallon bucket, to see if the drain can take the water quickly.

 

[Sponsor]

 

[Terry]

That works. Another test would be to pour 4+ gallons of water from a 5 gallon bucket, to see if the drain can take the water quickly.

Pouring right into the bowl works well.
A mid 80's toilet uses 3.5 gallons. There may be something in the trapway slowing things down, or you may have a flapper for a 1.6 gallon toilet in a tank the uses 3.5 and more.