Situation 1:

Had a flat in a tube that contained Slime. The Slime didn't stop the leak because the hole was rather large. I put a rubber patch over the hole and pumped up the tire with a mini pump . After I removed the pump, air kept leaking out of the Schrader valve. Apparently Slime had clogged the valve open.

Situation 2:

Decided to replace the Schrader tube with a brand new Slime tube with a Presta valve. Same problem while airing up the tube. Valve stuck slightly open and let all the air out.

Has anyone else had similar problems with valves sticking open from Slime?

Thanks!

Yes. In my experience, this happens when the valve is filled while in the 12 O'clock position (pointed down).

Pointed down is 6 o' clock, unless you use a 24 hour analog clock.

My bike came with slime-filled tires. They've never been able to stop a leak from even the tiniest pinholes. I've never had slime in my valves since I was careful to pump with the valve up top, but I threw the tubes away. All the slime ever did for me was to leak out where the hole was and make a huge mess that I had to clean up and made it difficult to patch the tire. It did make it easy to FIND the hole, I guess.

I wouldn't use Slime.

In stark contrast I have used slime for years. It has saved me more times than I can count. It has plugged up literally thousands of goat head holes, holes from glass, holes from those thin wires from car tires, etc.

Only twice has it failed me. Once, a giant nail punctured my tire, I did not even see it. The hole was too large for the slime to keep plugged. It would plug for awhile, then spray slime everywhere, then plug up again. I managed to get to class on time, but everything was a mess, including my backback. Another time something slashed my tire, I have no idea what, and I had an instaflat that nothing would fix, not even a patch. I didn't have an extra tube either, so it sucked, but it wasn't the slime's fault.

I think the one messy time was worth it for all the times it saved me from changing a tube in over 9000 miles of riding.

To the OP, as others have stated, inflate it with the valve stem towards the sky.

Slime is evil. Wretched, messy, useless crap IME.

But, Folks in warmer climates, often running lower pressure/higher volume tires, report success with the product. Go figure.

I'm a slime tube user too. Goatheads, glass, catclaws all lurk in the paths I cannot avoid. Have used the slime tubes for 1 1/2 years with great success. Tips:
Park your tires with the valve in the 10-11 o'clock position. If something is trapped in valve, unscrew the valve (ask for tool from LBS - mine was free). Clean out any small rocks or old slime. Rescrew the valve (important step). Park in correct position to let slime slide to bottom. Refill.
My LBS guy said to let the tubes heal themselves after a flat, then reuse. Works for me. He said the only time they are beyond repair is if a nail goes through both sides of the tube.

I only get a flat once a year or less. Perhaps the slime was old or something by the time I got my first puncture. The first thing it hit was a tiny bit of wire, and it didn't stop that. The next, probably 6 months later, was a T50 staple, one of the ones from a common staple gun, two very small punctures. It didn't stop that either. Then a year or so later, a tiny sliver of glass. Didn't help. Of course, by then all the slime had been blown out of the tube all over my fenders, so I didn't expect it to help.

I used to use slime, but stopped for a variety of reasons, mostly because of the low pressure thing; slimed tubes won't hold a higher pressure. Running at low pressure you get more punctures, and the tires wear out so faster. I also disliked that slimed tubes cannot be patched, and slimed presta valves cannot be inflated.

My rear tube in my roadie is slimed, and I routinely inflate it to 130 psi.

I am referencing pointing down as being at 12 oclock. At six bottom-up, presta toward the sky, the slime stays in the tube rather than being trapped by gravity.

Well, what is high pressure? I run 60-80 lbs in my 1.5 inch tires. I haven't run it higher than about 90 lbs ever, so I can't comment on any pressure exceeding 90 lbs. I have patched slimed tubes, you just have to wipe off the area with a hole.

If I only got 1-2 punctures a year, I probably would not run the slime, but in the summer, I get punctures pretty much every ride, especially in the rear, freaking goat heads are everywhere! When I take my dog out walking, she always gets at least one goat head in her foot! In some areas (the richer ones), the goat heads are less frequent because of better sidewalk/road maintenance etc. but I don't live in those areas.

Well, it's interesting and surprising to read that. I gave up on slime tubes two or three years ago; have they changed in that time? I've had the Slime plugs blow out of the tube at pressures over 60 psi or so; I prefer to inflate to 80-100 psi.

Nor have I been able to get my patches to stick to Slime tubes. I use a Rema vulcanizing patch kit, and usually have no trouble using it; I think the tube in my back wheel now has like a dozen patches on it. When I patched a Slimed tube, the patch stuck fine, and held air for a few hours; but the next day the tire was flat, and the patch had come completely off the tube. Is that really just me?

By the way, I've taken to using tires with puncture resistant belts... it seems to help.

I had to clean the slime off for the patch to stick, I used some patch kit from the motorcycle store. It didn't ever come off. I don't patch often though usually if I have a large hole I just replace the tube.

I have had the slime plug blow out, but only with the larger hole that one time. It was a hole about 1/4 of an inch in diameter. I don't expect the slime to plug holes that size or larger. It just plugs smaller holes for me, like goat head punctures, which are the majority of punctures for me.

Thanks for all the good tips everyone. This is my first experience using Slime tubes and didn't realize that it was important to position the valve at the 6 o'clock position when filling. Meanwhile, i discovered inside the box the tubes came in the special instructions for installing Slime tubes. The outside of the carton had instruction for standard tubes which mislead me to think there was no difference in using Slime tubes.

Thought I share the instruction sheet I found in the carton. It has a lot of good information oh how Slime tubes work. If you can't read the text in the image, click it and use the magnify tool to enlarge. Thanks again!

Instructions? Well there's your problem right there. You need to toss out anything resembling instructions as soon as you acquire any new device.

LOL! Ignoring instructions is what got me into this (slime) mess in the first place! All joking aside, I think using Slime tubes apparently requires a lot more thought about what's going on inside the tube.

I was airing a a tire on a friends bike. I didn't realize it had Slime in it and some of it spit back into the pump. It was a cheap floor pump, bit it's only good to about 45 PSI now instead of the 55-60 PSI it WAS good for.

no problems so far

mine can ...

I found this thread after doing a search for "slime clogged valve". Thanks to the different posts here I was able to fix my problem. I had originally blamed the problem on my pump, so I replaced it. When the same thing happened with this pump, I figured it had to be the slime.

Since my tires are pre-slimed, I used the green combo "valve cap / valve remover" to take the valve out of the inner tube. Once it was unscrewed, I could see that the part of the valve that was on the inside of the inner tube was clogged with Slime. The Slime had turned into a spitball-like substance. I pulled the gunk out of the valve, then screwed it back in to the inner tube. Pumping air back in was effortless.

the spit ball plug is what its supposed to do in the puncture , plug the hole when the air is escaping..

just when the psi Is not being added , same happens to the valve core .. at least Schrader are removable. .

Thought they banned that stuff in '09. Zombies in the valves are something to contend with.

Slime works for mtb tires with lower pressures. I tired to use Slime tubes on my road bike and they such at high pressure. They go flat for anything, after going through like three in a week I stopped using them, unfortunately I still have more that are useless

I had slime clog. My solution was to turn the valve cap upside down and tap hard on the valve actuator pin, which seemed to have worked. Sadly, one day i was riding in hot weather (over 95 degrees) and left bike outside while on a job for a few hours (after hitting something on the way there i'm guessing). The slime clearly did not like this high temperature, and the tire went flat with me clueless inside, i came out to a small pool of green and a floppy tire. I think from now on i'm going to be investing in tire liners AND puncture resistant tires.

One small little add-on... the slime definitely added weight, and you could feel it making the wheel unbalanced as it slopped around inside....

- Andy