In the past I have used Fix A Flat or similar inflate from a can
products to fix 9 out of 10 flats - and who knows how many I never
On the can it says "Do not use on tire sensor technology."
Is this just another Q-tip warning to be ignored or what gives? It
says it is non flammable -so what is the problem with simply leaving
the stuff in the tires forever.
On the rack next to it there were some color coded tire minders that
one apparently just insert in the tire stem and it should show green
if pressure is ok. Is this needed in addition to tire sensors?
Fix a Flat and green slime stuff basically work by coating the entire inside
of the tire and wheel with stuff that eventually cures to the consistency of
rubber. If that stuff coats the sensor, it would keep the sensor for
detecting the true air pressure.
On Wed, 2 Aug 2006 15:46:14 -0500, "Ray O"
So I should not use it. What is that sensor? Is it fastened to the
rim inside the tire? What happens when one fixes the tire with either
a plug or patch on the inside?
I think I need the ability to fix flats more that the this sensor
technology. What would I be giving up?
Not use what? The sensor or the Fix a Flat Stuff? I would only use the Fix
a Flat or slime stuff if you are in dire straits without a spare tire. That
stuff is not intended to be a permanent repair.
What is that sensor?
The sensor is a device that senses the air pressure in its environment.
Is it fastened to the
There is no rim inside the tire, however, there is a rim on the wheel. This
link from a tire repair equipment manufacturer shows some examples of how
tire pressure sensors are mounted on wheels:
What happens when one fixes the tire with either
If the tire is fixed correctly, air stops leaking out the hole.
When you say "I need the ability to fix flats" do you mean that you are
personally going to fix flats without taking it to a service facility? I'm
not sure what you mean by "giving up." There is nothing to give up if tire
pressure sensors are installed.
The proper way to repair a puncture in a tubeless tire is to locate the
puncture, mark it on the tread, dismount the tire from the wheel, scuff the
inside surface of the tread about 2 ~4 inches in diameter around the
puncture, apply rubber cement and the patch, re-mount and re-balance the
tire. So, you will need a bead breaker and a wheel balancing machine and
The no-so-proper way to repair a puncture in a tubeless tire is with a plug.
Plugs are supposedly not as safe as a patch, however, I would use one on my
tires if the tire has little or no life left. A plug can be installed
without any special tools other than the rasp and the plug insertion tool
and if you have a compressor, this can be done in the field.
Rather than attempt a poor repair, one would be much better off installing
the spare tire and then taking the flat tire to a qualified service facility
On Wed, 2 Aug 2006 17:25:57 -0500, "Ray O"
You got it! I'm not sure how it has been for you but I'm seldom able
to cancel the rest of the day for "a proper tire repair" or spend 45
min intercourseing with a spare tire - when in less than 5 min I can
fill the offending tire with slime or whatever and be on my way. The
same goes for using a plug on the road. I had two truck tires fail
(way TF out in the stick at critical work) at the same time and made
it to a repair facility - that did not honor warranties - except by
mail order etc. just spent the cash and gave the sob the old tires
that he said would promptly mail in for his own profit ...
I have never had a problem with plugs and at least so far - regard
them as standard repair. A proper scientific tire repair would no
doubt cost in excess of $60 - the cost of a new tire plus all the time
involved at either work or vacation. Not a good option.
Sorry if this sound slightly emotional but I fail to see any advantage
except a chance to sell technology for its own sake.
Is it a fear of hi speed blowouts?
Just the physical danger of doing a tire change on either a fwy,
street or road could really cancel everything IMHO.
It usually takes me less than 5 minutes to change the spare. I opted for
the lifetime puncture repair when I got my tires at Sears so I just stop by
after work to have the flat repaired and put back on the car.
I have not had problems with plugs either. A proper repair would involve
the use of a mushroom-shaped plug that is installed from the inside of the
tire. A dismount-repair-remount-rebalance probably costs around $45.
Studies have shown that the majority of the vehicles on the road have
under-inflated tires, which increases the chances of a blowout. The TREAD
act will require all passenger cars to have a tire pressure monitoring
system so you are starting to see some early implementation.
On Wed, 2 Aug 2006 20:19:15 -0500, "Ray O"
This must be part of a fuel saving program?
It is my understanding that the sensor on my S will only detect
differential pressure. So if all four tires are running at a sloppy
25 psi all is fine per the sensors. I should have 35-40 psi.
Is there any real difference between the different 'slime' or any of
the fix a flat products? They probably have all become non
Probably a combination of fuel savings and safety. The Firestone Tire -
Ford Explorer rollover problem was attributed to low tire pressure.
I believe that your understanding is correct, however, the likelihood that
all four tires will lose air at the same rate is pretty slim.
I've never used any of those products so I do not know if there is any
difference in them. Slime is water based and supposedly sensor-safe. I've
seen tires broken down that had those products inside and they are pretty
On Wed, 2 Aug 2006 21:16:19 -0500, "Ray O"
I think I saw Slime - but not in a pressure bottle. The beauty is to
both fix and inflate at the same time.
Will it harm anything else to just ignore any sensor lights and
In a few years when I need tires I'm inclined to just go to my old
tire place and have them check/rework the brakes if needed.
Any tire warranty is not worth my time or trouble.
Besides a tire plug kit, and a few tools I also carry a $15 compressor
and a can of fix a flat stuff.
On Wed, 2 Aug 2006 23:14:24 -0500, "Ray O"
After hearing all the pro and con - (so far!) - I'm getting some of
that "whatever generic pressurized flat fixer" that is non flammable.
I fully intend to ignore the sensors. Will the sensors block the
liquid/foam that I will be injecting the first time I have a flat?
I agree that the tires should be rotated and brakes checked every
10-15 k miles.
If the sensors are the kind that are inside the valve stem, then yes, they
will probably block the liquid/foam. If you Sienna has the low pressure
warning system that detects difference in air pressure, then there is no
sensor inside the wheel/tire.
On Thu, 3 Aug 2006 12:20:19 -0500, "Ray O"
Other than by doing - how can I find out if the stems are blocked. The
manual only says: ... system is designed to provide warning when tire
inflation pressure of one of the tires is critically low while the
vehicle is moving.
further on they talk about same size and construction and correct size
- to function properly.
Does this tell us anything?
(Just hate to attempt to look for a live one at the dealership)
The warning about all of the tires being the correct size leads me to
believe that there are no sensors, and IIRC, the Sienna does not use
separate air pressure sensors.
If you really want to be sure and you have access to an air compressor and a
valve stem tool, just remove the inner valve from one of the valve stems,
and after all the air has rushed out see if you can stick something thin
like a coffee stir stick through the stem. If there is no obstruction, than
you can re-install the valve stem, and re-fill the tire.
Actually, the system monitors hub RPM. The hub has what looks like gear
teeth on the outer circumference, and the speed sensor is basically a metal
detector. As the hub rotates, the teeth pass by the speed sensor and the
sensor sends an "on" signal when it detects a tooth and no signal when the
gap between the teeth passes by the sensor. The faster the hub rotates, the
greater the on-off frequency, and with a known wheel and tire diameter, the
frequency can be converted to wheel speed.
On Thu, 3 Aug 2006 14:54:56 -0500, "Ray O"
Fascinating - Is any of this visible to the eye? Is there a name for
this type of system as compared to "the other" kind of systems?
Then this should also eliminate any problems with a careless tire
change and tools.
The teeth on the hub should be. Look for wires on the strut, follow them
down until you find the speed sensor. Look at what the speed sensor is
pointing at and you should see the teeth on the hub. BTW, that speed sensor
is the speed sensor for the anti lock brake system, and the low tire system
just monitors the signals from the ABS sensors.
This is known as an "indirect" tire pressure monitoring system because it
infers low tire pressure by noting a different wheel speed for one wheel
compared to the wheel speed for the other 3 wheels and is not actually
measuring tire pressure. The advantage to an indirect system is that there
is no extra hardware in the wheels. The disadvantage is that it is not as
accurate as a direct system.
A "direct" tire pressure monitoring system actually measures tire pressure
and sends a signal to a receiver in the car. It uses a transmitter about
the size of one of those keyless entry key fob. The advantage of this
system is that it is accurate. The disadvantage is that replacing the
battery in one of those transmitters requires dismounting the tire.
On Thu, 3 Aug 2006 16:09:37 -0500, "Ray O"
In front I see - using a mirror and light and on my back - a wire or
hose at the top and one near the center and the CV boot - no moving
parts of the wheel can be seen near the hub.
At the rear - see the brake tube at the top and 'a sensor' of some
kind near the center of the wheel - whatever it is pointing at is
behind metal. Perhaps some disassembly would be required <grin>.
There is NO warning in the manual (that I found) about using monkey
s*** to fix flats.
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