Charging air tanks from another truck

Can it be done?

Whilst out in the car yesterday came across a youngish artic reefer driver stuck in a right awkward place just before a set of traffic lights on a local trunk route at 5pm.

Just before the lights the road widens to accommodate a left turn only lane. He was just where the road began to widen, in the right lane for straight on, but not far enough forward to allow all traffic to get by him in the left lane. So causing total chaos.

I didn’t notice the exact year & model number, but it was quite a newish Actros. (Not the very latest shape). I was more taken up with watching I didn’t get run over by the crazy horn tooting car drivers and finding a way to quickly get him to the side of the road.
Thought it might have lost its gears as Actros do from time to time as those of you who drive them will know.

Low air warning on with some fault message (I forget). About 6 bar in the tanks and no matter how much revved wouldn’t build one bit. No air leaks anywhere to be found.

At my suggestion we dropped the air lines off, pushed in the trl shunt button, (which he didn’t know about) then tried to see if enough air could be got to release just the unit brakes. Nope, not a chance.
Also, being a modern vehicle, it wouldn’t hold a gear. Presumably built in safety system.

Police turned up and started directing traffic. Driver phoned the breakdown number and they said about an hour. You should have seen the look on the coppers face :slight_smile:

At that point I apologised there was nothing more I could do and left him to it.

On thinking about it today, I was wondering if there is any way the unit & trl tanks could be charged from another truck?

Not that it would have been practical in this situation as to get another truck stopped along side would have meant entirely blocking the road.

Driver phoned me today. Fitter took 2.5 hrs to show up, diagnosed compressor u/s. Another 2 hours for tow truck to show up. :unamused:

Yes, am pretty sure its possible. Recovery firms do it to be able to tow breakdowns etc iirc

There’s normally a charging point on the chassis by the rear axles although you’d need an adaptor to fit it.

Harry Monk:
There’s normally a charging point on the chassis by the rear axles although you’d need an adaptor to fit it.

If the red line from the 2nd unit was put to the trl and the trl tanks charged. Then the stricken unit’s own red line put back on, will it allow air to flow back from the trl to the unit until the pressure is equalised (process could then be repeated) or is there a one way valve? Cieranc?

it can be done with an air line connected between the vehicle main test points

shuttlespanker:
it can be done with an air line connected between the vehicle main test points

No doubt, but really I was meaning without tools & equipment such as adapters.

Cant you connect red line to yellow line, I have no idea of the consequences though.
Don’t most trucks have a charging point before the drier?

Driveroneuk:

shuttlespanker:
it can be done with an air line connected between the vehicle main test points

No doubt, but really I was meaning without tools & equipment such as adapters.

No, I’ve asked this before and apparently you can’t charge a vehicle with air using just the airlines because there is a one-way valve fitted.

If you cannot get any air into the system, you can wind off the spring tension in the air chambers providing you have a spanner!

Seems like a backward move by the truck makers.In my day,yes i know its going back a while most lorries had an adapter fitted under the front bumper where you could fit the susie and charge the whole system.progress hey?

leylandlover:
Seems like a backward move by the truck makers.In my day,yes i know its going back a while most lorries had an adapter fitted under the front bumper where you could fit the susie and charge the whole system.progress hey?

Like!

There should be a number of charging points, on MAN’s for example on the N/S just behind the cab there are several, the ones with the red caps are the charging ones.

yes you can put air into trucks using another truck, we do it every day collecting dead non runner trucks,
a pipe with a test point at either end is the easiest way,
no tools needed , piece of cake ,
and as your man says you can always wind the chambers out if need be,
cheers
Mike…