Crossfire tire pressure equalizers

[powercat_ras]

The pressure read on the access valve is the pressure of the low tire if pressure drops more than 10 PSI below the Crossfire rating.

The explanation of the valve inside the Crossfire starts at about the 3:50 point in the video.

How Crossfire Works

[sajohnson]

Originally Posted by powercat_ras

The pressure read on the access valve is the pressure of the low tire if pressure drops more than 10 PSI below the Crossfire rating.

The explanation of the valve inside the Crossfire starts at about the 3:50 point in the video.

How Crossfire Works

Great video Randy, thanks for sharing! I'd never run across that before.

The red overpressure indication is a feature that the Cat's Eye system we have lacks. Otherwise the two products are very similar.

Both are sold with factory preset pressure calibration, available in 5 psi increments. Since we run about 61 psi in the rear (using the Michelin Load & Inflation Tables for RV Tires as a guide), I purchased the 65 psi Cat's Eye system. That way, when the tires are cold, and at 61 psi, the "eye" is open a bit. As the tires warm up and the pressure increases to about 67 psi, the "eye" closes. That opening and closing lets us know that they are sensing the pressure change.

Had I bought the '60 psi' system, the eye would remain closed all the time.

With the Crossfire, I assume owners round up to the next 5 psi increment and set their tire pressure there, so that when cold, window shows solid yellow -- no black or red.

One thing to keep in mind -- the mfrs of both systems recommend metal valve stems. Some rigs already have metal stems. For those that don't it's usually easy to get them installed. In our case, our View has 4 Alcoa wheels with metal stems, but the inner duals are the stock (OE) steel wheels with soft rubber stems. To make matters worse, Mercedes decided to use valve stems rated for 65 psi max., even though the tires have an 80 psi max. rating (which translates to almost 90 psi when warm). Very few people should have the need to run 80 psi, but the valve stems should be rated higher than the tires!

In any case, I spent a great deal of time searching for metal stems to fit those OE steel wheels and came up empty. It turns out there is very little flat surface area around the valve stem hole for a metal stem to seal. So we ended up going with short, stiff, rubber and brass "high pressure" (HP) 110 psi valve stems for the 2 steel wheels. They've held up well.

[Chaffeekid]

I used them for years on my semi's, and now just ordered a set for the Winne. So easy to add air if needed, so easy to check pressure, with a gauge or just by walking around at a rest area. Still carry a tubeless plug kit and a 6 gallon air compressor with me, just in case.
Bonus my Winne has a spare tire, don't know if I would try to put it on, but saves getting ripped off when your in the middle of nowhere on the side of the road with a flat.
Safe travels everyone.

[sajohnson]

Originally Posted by Chaffeekid

I used them for years on my semi's, and now just ordered a set for the Winne. So easy to add air if needed, so easy to check pressure, with a gauge or just by walking around at a rest area. Still carry a tubeless plug kit and a 6 gallon air compressor with me, just in case.
Bonus my Winne has a spare tire, don't know if I would try to put it on, but saves getting ripped off when your in the middle of nowhere on the side of the road with a flat.
Safe travels everyone.

It's good to hear they worked well for you on your big rigs.

Both Crossfire and Cat's Eye have few disadvantages and many advantages. Still, they seem to have not caught on with RVers. Part of the reluctance may be due to people mistakenly lumping them in with cheap Chinese "extensions" that are known to fail. Of course Cat's Eye and Crossfire are not extensions, are made in the USA and very high quality.

Another factor is that -- due in part to the "echo chamber" on forums -- the Borg valve stems are very commonly recommended. From what I've read, they seem to be well made, but they are very expensive (for valve stems) and I've read numerous reports of them leaking -- typically due to improper installation. Apparently it can be hard to get them to seal properly, even when the installation instructions are followed to the letter.

For less money, RVers can get the Crossfire or Cat's Eye system which seems to be more reliable (as long as metal or HP rubber/brass stems are used) and has the advantages of at-a-glance pressure check; single very easy access valve for air fill; and perfect pressure equalization.

[powercat_ras]

The Crossfire:

If both tires are at or above 10 PSI below the Crossfire's Pressure then the two tires have their air lines connected and the valve stem preessure = both tire's pressure.

If one tire is 10 PSI are more below the Crossfire's Pressure then the other tire with air pressure at or above 10 PSI below the Crossfire's Pressure air line is disconnected from the other tire and the valve stem. The normal or slightly low pressure tire is isolated once 10 PSI low point is reached if one tire starts to lose air. The low tire is connected to the valve stem.


So the low tire's pressure is readable on the Crossfire valve stem and a TPMS mounted there will read the pressure of the low tire all the way down. In the completely flat example it will read near zero.