Dual Tyre Pressure Equalisation System

wildebus

wildebus

Full Member
Posts
8,240
Likes
13,090
I like Tyre Monitoring Systems and bought a 6-wheel system for my LT Dually. I had problems with it as the extra weight of the sensors on the Valve extenders tended to cause the elbow extender to loosen and so loose pressure. The extender actually has loosened a couple of times without the sensors so was a hassle.

I searched around the internet for options and came across the Crossfire system and really liked the sound of the features.
This is the manufacturers web page on the problem - Crossfire - Dual Dynamics

You need to choose a kit that matches the Pressure you want to run at - they are no adjustable. When I first looked at these I was not sure what pressure I would be running the rear tyres at as didn't know my final running weight. Once I had near enough completed the conversion, loaded up with the most I planed to carry (which is quite a bit in the garage sometimes), took to the weighbridge and from that weight, further research and a handy and timely tyre pressure thread on this forum, decided 65PSI would be the pressure of choice for my rig.

So looked for a 65PSI Crossfire kit and as luck would have it found a nearly-new pair of 65PSI units on Ebay.com (US Site). The units with postage and import duties came to around £60 which is very good.

Installation was a bit trickier then the instructions and youtube videos would have you believe though (at least on my vehicle). In order to properly secure the hose on the inner wheel I had the remove the outer wheel to allow room for the 13mm spanner to tighten the hose nut. The sequence of fitting like this means you lose pressure while the Crossfire is partly disassembled (but not a big problem and actually means you get to check its operation as part of the install :) )
Overall, including jacking up the van each side, removing a pair of wheels, installing the kit and refitting wheels, retorquing, dropping jack and packing away took maybe 60 minutes.

Once Installed this is what it looks like on a LT/Sprinter Dual Wheel
Crossfire Installation by David, on Flickr

When at the pre-set Pressure, the display is Yellow and there are two black marks that line up with the marks on the surround
Crossfire Installation by David, on Flickr

This shows the Yellow section coming into view as I am inflating the tyres up to pressure
Crossfire Installation by David, on Flickr

When the pressure is 10PSI below the pre-set, the display is black. This shows mostly black as I am at around 55PSI
Crossfire Installation by David, on Flickr

Not tried this feature yet, but if the pressure is 10PSI OVER the preset the display shows red. This is quite possible to happen due to the way tyres warm up and it is more of a informational display rather then a problem one.


What I really like about this system is not just it tells you at a glance the pressure is at the setting you want when you do your walkround before driving off, but it keeps the tyre pressures matched between inner and outer tyres, plus it gives you just one fill valve for both tyres which is dead handy I think.
(to pre-answer one common question on this system, the unit is monitoring both tyres and if one tyre suffers rapid deflation, the valve shuts off. For a slow leak, the valves shut off when the pressure drops 10PSI below the preset (so 55PSI for me))

One thing which I am wondering a little about is if the extra off-set weight on the wheel will introduce any vibration? I suspect however it won't be noticable.

I might fit the TPMS sensors from the unit I already have to the central valves as I do have the system anyway and so could use the 2nd set of rear sensors on my little trailer.
 
Have a read of the info on the website I linked to learn why.

There will be a reason why a company has developed this kind of equipment and put a lot more research and knowledge into it than I have. So I am inclined to believe the benefits (especially as on two occasions I have had one tyre at way lower pressure than the other due to loose extenders and that was not good - and you cannot tell on a dually if there is this discrepancy (I certainly didn't notice until I got out the van and saw the tyre didn't look right each time)
 
I don't suppose you'll be able to sense imbalance on the rear, but you'd definitely
need a rebalance if a gauge such as that needs to be fitted to the front.
As the pipe goes through the rim cutouts it could abrade on the metal edge
with wheel movement, but the lines look like s/s braided so probably OK long
term.
 
Byronic said:
I don't suppose you'll be able to sense imbalance on the rear, but you'd definitely
need a rebalance if a gauge such as that needs to be fitted to the front.
As the pipe goes through the rim cutouts it could abrade on the metal edge
with wheel movement, but the lines look like s/s braided so probably OK long
term.
Click to expand...
The kits come with apieces of rubber hose (looks like fuel pipe to me) that goes over the hose for the inner wheels to address that rubbing and potential abrasion :)
The elbow for the outer wheel is touching the wheel and I might put a bit of rubber on that to isolate it though.

The kit looks a bit old fashioned and judging from the intro video, has been around for a while, but I think it is one of those "if it ain't broke, don't fix it" type of products and feels VERY robust and high quality (hope so anyway!)
 
Ok if no leak over from one tyre to other,vibes may be a prob at high speed but most dont go to fast im sure.
I would prefair in cab monitor to be honest.
 
trevskoda said:
Ok if no leak over from one tyre to other,vibes may be a prob at high speed but most dont go to fast im sure.
I would prefair in cab monitor to be honest.
Click to expand...
Trev, did you read the info on the website? It links the two tyres to equalise them dynamically so you could say there is a "leak" from one to other but in the way that is good.
I will probably fit the TMPS to the central valve as well. I could add some balance weights opposite the gauge possibly for some approximate balance .
 
Thought this kit came out a while ago .... Read a posting on a sprinter forum yesterday from someone who said he had been running a crossfire system for 20 years! (A post 5 years earlier said 15 years so it sounds like he has had just the one kit so bodes well for product longevity).
 
wildebus said:
Trev, did you read the info on the website? It links the two tyres to equalise them dynamically so you could say there is a "leak" from one to other but in the way that is good.
I will probably fit the TMPS to the central valve as well. I could add some balance weights opposite the gauge possibly for some approximate balance .
Click to expand...

If one got a hole then would both not go down.:scared:
 
trevskoda said:
If one got a hole then would both not go down.:scared:
Click to expand...
Nope! That is a key feature of it. Equalises between the two tyres upto 10psi below preset PSI and below that the valves are shut off so one tyre cannot impact the other past that level, but the display tells you there is low pressure.
My limited experience of dual tyres has already taught me that visually it is not obvious one of the pair is low, especially if it is the inner tyre so this kind of info is good to have. Plus being able to put air into dually tyres as easily as into a standard single tyre is ace :)
 
wildebus said:
Nope! That is a key feature of it. Equalises between the two tyres upto 10psi below preset PSI and below that the valves are shut off so one tyre cannot impact the other past that level, but the display tells you there is low pressure.
My limited experience of dual tyres has already taught me that visually it is not obvious one of the pair is low, especially if it is the inner tyre so this kind of info is good to have. Plus being able to put air into dually tyres as easily as into a standard single tyre is ace :)
Click to expand...

Cheers thats handy though i have valve extenders on my rear units which i find handy but i like they tyre pall sys with monitor in cab,expensive mind you.
 
I had the Tyre Pal system on a previous van and liked it.
When I got the LT, I bought this 6-tyre system - CARCHET RV Trailer Car Solar TPMS Tire Pressure Monitoring System +6 Sensors LCD Display: Amazon.co.uk: Car & Motorbike - plus some valve extenders (you helped point me in the direction of them).
But I found the extra weight of the sensors made the extenders move around and wasn't comfortable with that.
I didn't seem to be able to tighten them down to lock in place. That seems to be quite a common thing as I have seen these inserts that are shaped to fix in one of the wheel holes with a centre for the extender to go through so it cannot move around.

Just done a search ... This kind of thing (which I don't have) - Valve Stem Stabilizers - RealWheels
 
Last edited:
trevskoda said:
Cheers thats handy though i have valve extenders on my rear units which i find handy but i like they tyre pall sys with monitor in cab,expensive mind you.
Click to expand...

Just go half way Trev. and fit those tyre valve cap monitors, a few quid just have
to be prepared to get off your butt once in a while and look. That's the trouble with
young people, everything has to be on a display screen and inside !

I don't know if they're available in >60-70psi though.
 
Just some other gimack to go wrong don,t see any on twin wheel lorrys. Just a hit with hammer will tell if pressure down after a bit of practice you,ll soon know if ones low
 
witzend said:
Just some other gimack to go wrong don,t see any on twin wheel lorrys. Just a hit with hammer will tell if pressure down after a bit of practice you,ll soon know if ones low
Click to expand...
excellent advice :) do you lick the dipstick to check if the oil needs changing as well?

PS. could you tell me where to calibrate my hammer?
 
wildebus said:
excellent advice :) do you lick the dipstick to check if the oil needs changing as well?

PS. could you tell me where to calibrate my hammer?
Click to expand...
If your silly enough to make such a reply theres no point trying to educate you
 
wildebus said:
I had the Tyre Pal system on a previous van and liked it.
When I got the LT, I bought this 6-tyre system - CARCHET RV Trailer Car Solar TPMS Tire Pressure Monitoring System +6 Sensors LCD Display: Amazon.co.uk: Car & Motorbike - plus some valve extenders (you helped point me in the direction of them).
But I found the extra weight of the sensors made the extenders move around and wasn't comfortable with that.
I didn't seem to be able to tighten them down to lock in place. That seems to be quite a common thing as I have seen these inserts that are shaped to fix in one of the wheel holes with a centre for the extender to go through so it cannot move around.

Just done a search ... This kind of thing (which I don't have) - Valve Stem Stabilizers - RealWheels
Click to expand...

Mine have clips which have a pinch bolt to fasten to rim,the clip has a u section where the valve neck locks in,trucks all use them.
 
Byronic said:
Just go half way Trev. and fit those tyre valve cap monitors, a few quid just have
to be prepared to get off your butt once in a while and look. That's the trouble with
young people, everything has to be on a display screen and inside !

I don't know if they're available in >60-70psi though.
Click to expand...

I do a walk round before each trip but if your running double back wheels and get a flat on inner one the dash monitor is sure to be the safe option for quick stop and change before the tread flys of with overheating.:scared:
 
I have a feeling the blokes would run out the rear door when you in for a Tyre balancing session.
 
You must log in or register to reply here.

Users who viewed this discussion (Total:0)

Back
Top