I am purchasing a forum members XJR parts car out of town with a bad engine. The air suspension is deflated since it’s been sitting for a while. I am told that it is functional and will raise when the engine is running. In this case, the engine will not run but the compressor I’m told will run. I am going to winch it onto a trailer but I need the suspension fully inflated to do so. Is there a way to do this manually somehow? How have others towed their non running x350s with air suspension?

 

Have you thought of powering compressor directly with 12V? Just don't let it run for more than 90 seconds? Compressor is not powered from engine, it is powered from battery.

 

yes but does powering the compressor inflate the airbags? I’m assuming there is some type of electronically controlled valve to inflate and deflate the shocks.

 

Normally, the ASM won't initialize the compressor until the engine is started (I think...) If you turn the key on but you don't have compressor startup, you might be able to run the compressor by applying 12 volts to its trigger line, but I'm not really sure where that is. It would be one of the relay boxes under the hood.

I still don't know if running the compressor is enough. The ASM may realize the engine isn't running and therefore give zero {blanks} about what you're trying to do, and if that's the case, I'm not sure where to go.

In other words, compressor on by itself is not enough. You have to enable control of the valve body, which requires the car (and thus the ASM) being powered on. I just don't know if the ASM has an engine-running interlock. I don't think it does, because it can wake up from time to time and check the car's state, and raise it if it's sagging, even with the car shut off, but it won't do that forever, and a battery and compressor protection feature.

 

Yes people have done this but it will require changing the connections on top of the air struts. Usually they install a tire valve so you can just inflate the struts to a set amount of pressure and leave it that way.
Don't know how hard it is to do that but since you will need to do this on site maybe not a workable plan?
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THIS.

Pointless to try and fight the AI (Artificial Idiot) that controls the compressor and solenoid distribution valves, even if you sub-in an air hose right at the compressor outlet tubing. Which is not easy, as that requires pulling a wheel, then also the fender liner to get to it.

One needs the right sort of fittings. For safe use, that means brass ones rated to high pressure, given the system operates at up to a tad over 200 PSIG.

Lower-pressure rated plastic ones risk shattering and injury.

That said? I wouldn't bother. Too much like "work" for simple flatbedding, empty of passengers or luggage.

I would use an ignorant jack to raise the dead vehicle, place a stout heavy-guage black plastic garbige bag into the stretched-out suspension at each corner, and fill each bag with a can of expanding packing foam.
Let cure. Remove jack. Flatbed it on the foamed "suspension".

Back home and unloaded, jack it again to make space, cut the foam away with a common serrated "bread knife."

Do be careful enough to avoid brake lines and wiring, please?

Wouldn't want to trade "Red-neck mechanic" credentials for a "Darwin Award".

And thennnn.. given lesser rations of time, and greater availabilty of money?
Sweat or cash. Pick only one.

I'd have a rented forklift ordered up, standby drop and recovery, load the Jaguar as-is, but from the side of the rollback.

Easy for me to say, but I'm far from the Lone Ranger on having done that stuff ... more times than a few. Many an auto wrecking yard runs a forklift every day, all day.

First Log, Siagon Support Command, Long Binh RVN and not-only wasn't exactly shy about their use, either.

 

Theoretically it might be easier than you think, but a note of caution; if you manually operate the compressor you run the risk of over pressurizing the reservoir as the embedded pressure sensor is only read by the air pressure module which you technically will be bypassing.


If you pull out the compressor supply fuse (A) in the front power distribution box, then with a multi-meter on low ohms setting measure from ground to each side of the vacant fuse slot, one side of the fuse will give a very low reading.....that is the compressor motor.
To power the motor you just need to apply 12 volts to that point (only run for a short burst to prime the reservoir with some pressure).

Meanwhile locate the suspension valve block under the spare tyre and disconnect the 6-way connector CR22.
That isolates it from the controller module that resides behind the rear seat.

Now, you should be able to trigger air from the reservoir to each corner of the car by simply connecting a 12 volt supply to the valve block in a manner that you can briefly "switch" power to each valve individually to raise one corner at a time.
Your 12 volt source for this task probably doesn't need to be a full sized car battery although you have the battery in the trunk close by anyway.
Connect a 12 volt lead to pin 6 of the valve body plug (Yellow/Green wire). That 12 volt supply is a common connection input to all 5 valves contained in the valve block assembly.

Next, you need to run a ground wire that you will use to momentarily activate each valve individually also via the CR22 plug to raise each corner.
The fifth valve in the valve block I suspect (other members might correct me on this) opens the valve body (manifold) to receive the reservoir pressure, so you may need to have this valve activated along with any other of the four valves to get air to flow to the desired corner.

So, on the 6-way connector CR22 (valve body end):-
Pin 6 is your 12 volts in,
Pins 1, 2, 3 & 4 are your four individual corner connections that you will touch to ground to momentarily operate the desired valve.
Pin 5 you might need to also trigger (touch to ground) at the same time as triggering any pin 1, 2, 3 or 4 to get air to flow. (I am not 100% sure you need to trigger this valve but I would assume it is the master supply control to the shared air manifold).

Hopefully you will be able to start to raise the car, bearing in mind that you may need to pulse the compressor several times to supply enough pressure. The front struts probably need more pressure to lift due to front weight distribution.
Good luck and please let us know how you get on.

 

Fair certaiin that the reservoir tank is rated at over 300 PSIG working pressure over some drawing-board expected service lifetime, which would include an allowance for degradation (it IS Aluminium, is it not?) AKA 50% greater than the compressor is able to deliver, best-case. Could be it actually stands over 400 PSIG.

Even if the single-stage WABCO could deliver higher pressure, the tubing would burst before the reservoir tank.

OTOH, the business of locating it where the spare wheel serves as a shrapnel shield in case it were to burst does make one wonder if cost-cutting bean-counters cheated good Engineering, yet again, another time.

 

If available (and affordable...), I would use a towing truck with a crane:

I don't know whether there is the possibility to rent them only for lifting the car on/off your trailer?

Just brainstorming...

Best regards,

Thomas

 

I’ve never seen one of those outside of Europe. The car is 8 hours from me so a tow truck is not feasible.

 

This is the exact information I was hoping for! Thank you so much for it! I have a power probe that will make this job much easier. My question; do I power and ground the connector side or the controller module itself?

 

You do not want to power anything related to any on-board modules if you take this route. You will be "standing in" for the decision-making function of those players.

At the solenoid control block, your want total disconnect, electrically, from the vehicle. You will furnish power to only the block not to any other connection to the 'upstream' as the vehicle's logic uses to control OR sense it.

Your observations, no longer the sensors, drive the decision as to how much air to provide to each strut, in turn.

The compressor? Not a certainty that it is even functional, is there?
If it IS OK, same approach, Disconnect it, power it ONLY, no power back into the on-board systems.

If NOT functional, a(ny) 150 PSIG to 175 PSIG rated utility / Harry homeowner air compressor plumbed into the solenoid valve block should be able to get a chassis with no passengers or luggage up by enough to clear it onto to a rollback.

Before doing ANY of this, do one other thing first.

Discuss the down-on-the-bump-stops challenge with whomever you are engaging to do the flatbedding.

They do more difficult tasking as part of their normal workweek, year after year.

Would you believe it? The better ones may just chuckle.
They already have more than one way to do this without damage.

It's their "rice bowl" after all.

 

If I were to use a flatbed I would be paying them $4000. The car is 540 miles away from me. I am planning on using a uhaul car hauler and my winch. Worst case I can snag the strut master coil springs from my running XJR and put those on the parts car. It’s not too big of a job.

 

Ah, well.. fully "DIY" is it, then? Don't mess with the suspension at all. AKA just leave it on the bump-stops.

Finesse it onto the trailer as if it were a large lathe or milling machine and had never had wheels - of its own - to begin with.

Cost of transport would exceed their value, or I'd lend you a set, but here's one of the favourites in my rigging arsenal::

https://www.northerntool.com/product...ch-2-5-5000051

These are engineered for "ganging", can be latched together either/both of side-to-side, and/or end-to-end, to create a "magic carpet".... as I have needed, if seldom, for traversing soft asphalt on a hot summer's day to prevent the rollers sinking in.

Where I have hard surface all the way, or can create it, I use these ones:

https://www.northerntool.com/product...ch-1-5-5000042

Either way, for your tasking, just two skates at one end of the motorcar, clear the interference point at the trailer, then move them to the other end and traverse the other half of the range.

One DOES have to saw a few bits of timber to cradle the tires to the skates. Ready-made dolly's for that can be had, but cost more. And may use "casters" which - as works of the Devil - are but accidents waiting to happen.

Skates are not even of the same race as silly-fool baby-cakes "caster" wheels.
Skates are the "big boy pants" in the rigging trade.

Big ones we use to move turbines. Or whole buildings.

These goods, and a GREAT deal more in the way of solutions, can be rented. Search MHE and rigging categories.

Oh.. and if I forgot to mention it? Avoid "caster wheels" ... same as the wise would try to avoid nasty social diseases.

 

great suggestions! If only I could find some locally. I am going to look into that. I am going to experiment on my car with manually inflating the air suspension using the information you provided. My air suspension was removed and if the components are still there I can power them with my power probe and see if your suggestions work. I don’t mind running the risk of damage on my car since the parts car is the one with functional air suspension.

 

Hotlanta? ***** sake, mate *I* know where to find machinery skates, "locally". Start with United or Sunbelt, Google "MHE rentals" or "Riggers supply"

Moving awkward 'stuff' is a universal industry. Has been for a longish while. See "Stonehenge"

Meanwhile.. Northern Tool has a subscription that gets free shipping. I love that because it seems to be only HEAVY stuff I ever buy from them, what with lesser-quality Harbor Freight within a short walk from the house!
H-F traditonally sold stuff the Chinese would never buy, in China. Northern's goods are not even all Chinese, but when they are, it is the stronger and more durable goods the Chinese worker-bees DO buy for their own use in China.

I've bought my "many" skates when on promotional sales or "Buy one, get one free" at average of half the usual price.

Griillage (wooden timber) is easy to find locally. Avoid pressure treated and you can heat your home with the scraps once the job is done.. Don't use screws or lag screws. Wood will split. Bore holes and use carriage bolts instead. Cheaper that way, too, as the bolts, washers, and nuts are more readily reusable, some other tasking.

Rope works as well as before the time of the pyramids. Ratchet straps may be better if you were not trained on rigger's or sailor's knots. Cheap recycled rubber doormats from the poor folk's stores can be cut to protect stuff at tie points. Old tires are gold as shock or impact wedging and padding.

Hacker's Law on rigging:

If you break the load, break the tackle, break a fingernail, or even break a sweat? Back off, plan better. You are doing it wrong.

In other words, your brain and the tackle, properly applied, does the work. It is never about "muscle".
Focus matters most.

"KISS" method. Do the recovery as ONLY a recovery. Mess with the air stuff only after safe home and done.

Distraction kills - in either the rigging or highway-hauling games.

 

As Bill said, the method I described is aiming to totally isolate the compressor and valve solenoid block from any of the car's control systems to give you crude manual control.

If you pull the fuse F6 and/or the relay R1, then you have isolated the compressor.

When you separate the connector CR22, you will have effectively isolated the valve block from the air suspension control module, allowing you to apply voltages directly to the valve block without any back-feeding and possible damage to the control module.

This hopefully should help you trailer the car.
Good luck!

 

It is useful advice for more than just the trailering exercise - which I remain convinced is better done by more direct rigger's craft.

I thank you for it as confirming steps useful in tracing component faults, in general.

As I am playing at myself. At least when not distracted by my most dominant of skillsets.

That of Master Procrastinator.

"World class" even

"Age thing"? Well.. it will do as an excuse whilst I find a better one? Not in a hurry, are we?

 

I haven't read the entire thread, but...
I had my car towed onto a flatbed with the front suspension on it's stops. Just couldn't steer much (which is why it was flatbedded).
In normal circumstances, if the car is down like say overnight, the air suspension system will raise the car just on unlock, supposing there is enough air in the reservoir which can do one full raise. No need to run the engine (except to run the compressor).

Therefore, I'd be inclined to run the compressor directly from 12v for a short time as stated, which should replenish the reservoir. Perhaps with the ignition on so the ASM doesn't know something funny is going on. I haven't tried this because it was unnecessary to get onto a flatbed (and with a blown strut it wouldn't have helped me anyway)

 

It will be necessary to have the suspension fully inflated in order to get the car onto the trailer. Will the car even roll when resting on its stops?