I used GP 5000 TR for years and was happy with them. Two days ago I installed my new GP5000S TR and it leaks air like there is no sealant. 
I am glad I only replaced one tire to check this. I do not know what to do now. I have to pump it before every ride and the next morning it is completely flat. I used Continental Revo Sealant, just like before. Any advise?
It’s the tape.
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If its completely flat, there is a big leak somewhere. Either its not seated properly, or the tape is faulty (as above), or there’s a leak around the valve, or the valve itself.
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It’s never the valve though, it’s the tape.
We’re the last tires the 5000 TL? Those were lined while the TR S is unlined. The TR S need sealant to work, while the TL didn’t. It’s best to give the TR S a bit more sealant and a good spin.
It’s the tape though.
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Apparently I’m bad at seating valve stems into the tape properly because on most of my wheels I have to resort to using a little piece of an old inner tube as a kind of gasket on the base of the valve stem to get a good seal (even on fresh tape and using the hot awl trick to make the valve hole). Very effective fix though!
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Could be the valve core, if its not screwed in properly. Had that happen. Also often the tape around the valve - it can need a bit of shaking to get sealant to go there, as its on the inside of the rim.
How tight are you tightening it? You’re probably over tightening it or no checking it after you fitted the tire. If you over tighten it, the cone seal won’t work or you’re hurting the rim bed. If you’re not tightening it after the tire is inflated, the rim has changed shaped and it needs a few twists. Just lightly tightened is enough as the air pressure itself holds the valve in.
You’d know when the valve core isn’t doing its work. It’s the tape.
I guess I must be over-tightening then? Always thought if it was losing air I needed to tighten more so the rubber deforms into the irregularities of the hole - that usually helps but doesn’t fix it completely - and we’re often talking audible leaks here. Doesn’t seem to matter the brand of either stem or rim (or carbon/alloy), even on matched brands (roval/roval). The only combo where I’ve never had an issue is mavic stems on mavic rims.
At this point if there’s a significant leak when inflated dry it’s honestly easier to just use a bit of inner tube from the beginning rather than the cleanup involved in getting as far as sealant to find out if it will finish the job or if I’m going to have to remove a milky tyre to start troubleshooting. Also cheaper than re-taping if it solves the issue - am still cutting bits off the same tube I started using 5ish years ago and have barely used up any of it 
Maybe next time I’ve got fresh tape on a wheel I’ll see what happens if I make the stem less tight.
If really is a massive leak, you should be able to hear where it’s coming from.
If the leak is actually from the tire, you should see sealant coming out of the source.
The rim tape could have been damaged during install.
Sometimes, it takes a few rides on a fresh setup for the sealant to fully do it’s trick and make for a solid system.
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Is it pissing air fast enough that you can hear it? Should be straightforward to figure that out.
Or is it going flat overnight? If so, I’d guess 60% chance the tire isn’t fully seated and 40% chance the tape is bad. If you’re using a normal floor pump, I’d put it at 70-80% chance it’s the bead. Using a pump designed for tubeless installs helps massively (or an air compressor).
Easiest path forward - pull the tire, pull the old tape and valve, clean the rim, install new tape (at least 2x around) and valve, install tire. Before pumping, use a wet/soapy rag to get the sidewalls/bead area wet and sudsy (this helps the bead snap into place). Then inflate. You should hear at leasts one big pop as the bead seats, possibly two pops.
I’m in the exact same situation. My 5000 TL where great but the 5000S TR don’t last 24 hours. I also have Lightbicycle wheels with no holes in them so it certainly can’t be the tape, there is none. I’ve also unseated and reseated them a few times with no luck. My next step will be to try the old tube trick and follow that up by some new valves if it doesn’t work.
The leak is definitely slow becasue I can easily do a 1.5 hour ride in them holding air. But for the moment I’m afraid to try andything longer.
Did the tire go PINK PAP? How much did you inflate it to? How much goo did you put in there? The TR S is unlined, so the tire itself will eat some of the goo right off the bat.
If you don’t have rim bed holes and you’re still losing presssure, it’s coming out the bead or tire. Lay the wheel on its side and roll the puddle of goo around, letting the gunk get to where it needs to so. Repeat for the other side. Sometimes there’s a joint on the tire or rim, some dirt, or the bead has a gap that doesn’t seal perfect.
If that doesn’t work, fill your bathtub up with some water. Slowly move the tire through the water, looking for where bubbles form. Figure out what to do from there.
Right. I did not realize the old tire was TL and the new one is TR. However there is no tape. I am using Fulcrum Racing Zero wheels. They do not have wholes in the upper layer. The tire leaks throw the wall. I checked this in a sink basin. The manual says I only need 30 ml of sealant. I added a little more.
https://www.continental-tyres.co.uk/b2c/bicycle/tyres/grand-prix-5000-s-tr.html
No, there is no sound, it leaks throw the wall.
Fwiw, it took my GP5000 TR S tires about a week before they stopped going flat over night. I used 30ml of Orange Seal. I’ve always thought this is fairly normal for tubeless setups though.
If you’re convinced it’s leaking through the sidewall, my suggestion is to just keep riding them for a few weeks and see if the problem goes away. Make sure to keep an eye on the sealant level.
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If it’s leaking through the sidewall, you usually see little sealant bubbles on the outside of the sidewall.
I’d try deflating, use a rag to get soapy water on the bead/sidewall, remove the valve core, and use an air compressor or tubeless pump to inflate. If you hear the plink/pop, then install the valve and reinflate. If you don’t hear the plink/pop, the bead probably isn’t seated.
Or, add a bit more sealant and give it a few days? Though I’ve never actually needed to do this. It has always been the bead not seating, old damaged tape, or a faulty tire (had a bad batch from WTB once - pinhole leaks all around the sidewall, but I could see the sealant bubbling through - returned those ones to the LBS).
Can you put some water in the bathtub and submerge the tire to see if it is leaking from one spot or several places around the tire?
I did this. The bubbles come all over the sidewall. They are leaking slowly, so no sound is heard, but it’s all over the side.
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I use at least 50ml, and if it’s a new tyre, I’ll probably top up another 30ml a couple of weeks later. A lot of the initial sealant gets used up coating the tyre, tape etc. I’d rather carry a little extra weight in sealant than deal with punctures.
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