Slime is wonderful stuff but it keeps fouling the valves in my tubes. I have to deflate the tube, install a new valve, then reinflate the tube. Almost as much of a pain in the butt as fixing a flat. Anyone know of a way to keep this from happening?

I've never had a good experience with slime or other sealers. I used it in a tubular (sew-up) one time and had it spray out through the hole after I pumped it up and took a closer look - went directly into my eye. Another time it leaked inside the tubular tire and came out the easiest place - right around the valve stem. It would have filled up the inside of the tubular rim if I hadn't seen what was happening and pulled the tire of right away. Ended up throwing both of those tires away anyhow. Then there was the time I went to add air to a goped tire and all this slime than a previous owner had put in it came spraying out the valve, gumming up my good pressure gauge. No more slime for me. Your results may be different.

Um the obvious solution is don't use the slime. It is made to plug holes and that is exactly what it does. It doesn't care if the hole is supposed to be there or not.

I'm glad I didn't go that way. Too many not so happy stories about that. Maybe you should try better tire, tire liners and avoid glass and other sharp crap.

Gotta disagree. It adds a lot of rotating weight to the wheels and I've never seen a benefit from it. A friend of mine used it in his tubes and when one did get punctured, all the slime did was make a huge mess inside the tire. I know a lot of people who have tried it and none of them continued to use it. Fouled valves are common and in my experience, it just doesn't work. For less weight, you can put thorn resistant tubes inside of puncture resistant tires and have much more protection (IMHO).

Slime's good stuff, but not in a bike tire. Car tires have a lot more places (besides the valve) for the Slime to go than a bike tire does.

If you're dead-set on Slime, try one of the pre-Slimed inner tubes...it's thicker and stickier than the pour-in Slime, and stays put on the walls of the inner tube instead of fouling the valve, usually.

You are holding the bike upright and positioning the valve about near the top of the wheel (between 2 o'clock & 10 o'clock), right?

Slime Tire & Tube Sealant » Faqs

+1 I screwed up a pump on a tire that I didn't realize was Slimed.

In my experience with Slime, it works OK for larger lower-pressure tires, but it's worthless for small high-pressure tires like road bikes have.

But it's still a total pain in the butt, and good tires and tubes that are appropriate for your riding conditions make it superfluous.

found it worked excellent but it gummed up the valve
so i took it out

Slime was made, as I understand it, to be a emergency fix for car tires. It never made sense to me to put that thick stuff made for cars in a small bike tire as a preventitive.

However, there are lots of really thin sealants for tubeless mountain bike setups. Stan's is generally the most popular. I put it in some 700c tubes with removable presta cores on my commuter. Only 1 oz per tube. It's a lot lighter then slime and will actually do the job, if needed.

If you just jam down on the valve stem to open it up, you will probably get sprayed by the sealant. If need be, rotate the valve to the 5 or 7 o'clock position and tap the valve, and let sit for a few seconds so the selant can fall back into the tube.

Generally speaking, I have a good pump with a gauge, so I just stopped bothering to open the presta valve before inflating, and just let the pump open up the valve for me. This way the sealant gets blown back into the tube.

Anyhow, it's been used on mountain bikes for years now, and I've seen exactly one gunked up presta valve in the busy Dallas bike shop I work at. Lots of trashed slime tubes, though.

only IF the air is only going IN and none escaping the valve
it comes out with any air escaping when there is a pressure difference ,
lower on the outside. ie 14 psi at sealevel .

a valve is just another leak to seal ..

I have used a sealant, not the Slime brand, all winter on my mountain bike tires. I have pulled a number of thorns out of the tires and have no flats as of yet. The valve (a Schrader) is working fine. I really had my doubts but I have been happy using it on this particular bike. However, my understanding is that it is only good for a few months so I have wondered what will happen next winter when I ride this mountain bike again. Will I need new tubes and new sealant? If so, I might just try using tire liners instead or thorn resistant tubes.

I lived in Az and used Slime for several years. It worked well sealing punctures from those red thorns and was usually better than carrying a spare tube. I prevented valve fouling by rotating the valves to 4:30 or 7:30 while parked so the sealant drained from the stem. Then, before next ride I could add air without issue. I never had a problem, but fixed a few friends' tubes that did: squirted some water into the valve, capped it, and waited over night.

Eventually when a punctured tube would get patched, I'd just hang the tube at the puncture to let the sealant drain from that area, then patch as usual.

I was a Slimer for years. Valve at the top for a half hour before pumping. Add a little air at least twice a week to keep slime from coagulating in the valve.

Soak your pump head in water if it ever gets Slimed.

I tried a slimed tube once. Between the added weight, and the fact that it fouled the valve so I couldn't add air when I wanted too, I removed and trashed it.
Much more trouble than it's worth. It works good in my wheelbarrow and tractor tires.

Yeah, my first bike came with slime already installed in the tubes, and after a couple of flats I was constantly getting sprayed by green ick every time I topped off the air.

When I eventually swapped out one of the inner tubes for a regular one, I was happy to discover that not only wasn't I getting sprayed with slime but it was much easier to pump air into the tube.

Shortly after I commenced bicycling back in April of 2011, I inadvertently purchased two inner tubes (from a nearby Walmart) that were slime filled as I had gotten a flat on a Sunday and the LBS was closed. While the tubes were fine, the slime presented other problems, so I removed the Schrader valve and added water to dilute the slime, then squeezed all the slime out of the tubes. I’m still using those tubes––minus the slime––3 years later. From that point afterward, I’ve always made certain that the inner tubes I purchase are slime-free. I’d much rather patch the tube than deal with the slime issues.

Not really true, ask a mechanic or someone at a tire store how much they love chiseling the liquid slime or fix-a-flat off of rims so they can get a new tire to seat and hold air. For both car tires and bike tires, the answer is patch and inflate, and slime sells patch kits for all kinds of tires. There is just no reason to use the gunk. I read a LOT of reviews about the pre-filled slime innertubes and the thing that came to light is that bicycle tires are typically inflated to very high pressure, and that pressure means that instead of slowly oozing out of the hole and drying to stop the leak, it sprays out until there is none left, which spotwelds the innertube to the inside of the tire and rim.

I can't disagree with anything you said. However, Slime's been a real lifesaver for me when four-wheeling up in the mountains or out in the desert. Is it the best solution? Not really...but sometimes it's better than nothin'.

Also, I wonder if some of the issues with Slime blowing out through a small puncture in a high-pressure tire might be if the user was using the Slime meant for tubeless car tires...that is, with the little particles of rubber. I haven't gotten bike Slime in quite a while, but I remember that it used to have fine polyester fibers that would "clot" in a bike inner tube's puncture, keeping leakage to a minimum. I could see car Slime not working very well in a high-pressure inner tube.

To answer the OP's question , liking slime or not , you need to put the valve at 12 o'clock to keep the slime from going into and clogging the valve as you pump up the tube (tire) . Always spin the wheel before doing this will help keep the slime from getting into the valve .

Personally I'd rather have a patch kit(the kind that comes with a t-handle tool that you ream out the puncture with, and then jam a plug of rubber and sealant in to the hole) and a little 12v air compressor, for 4wheeling. In the case of bikes, spare inner tubes or tube patch kits.

Goat's head central here. I have always let the wheel sit with the valve at 4 or 8 to allow the goop time to drain from the valve before filling.

slime will plug a valve. it is important to have the valve up high when putting air in
I have used slime, but wont again, in my bikes. plugging valves, spraying onto the wheel, etc etc.
plus I have a morph pump, it works best when on the ground. the inflator hose will not reach a valve at anything up high

I have switched to Kevlar tires and thorn resistant tubes and haven't had a flat in over a year, which for me is great since I put over a hundred miles a week on my bike

I have high praise for green slime. I went out this morning to get on my bike and the rear wheel was flat. On careful inspection, I found what looks like a industrial staple. I carefully pulled it out with needle nose pliers and filled the tire up with air. Without having slime in my tires, I would have had to replace to tube. With the slime, I rode around the block, filled it back up with air, and went on my 20 mile ride with no problem. The slime has also saved my wife's bike from a flat when she got a thorn in her tire.