Robinair AC1234-4SL R-1234yf Machine with Mechanical Scale Lock
Every A/C service machine weighs the refrigerant it moves, and every one of them does it on a scale that does not enjoy being driven around. That is the problem the AC1234-4SL was built for. It is the version of Robinair's R-1234yf machine fitted with a mechanical scale lock: a physical lock, operated from outside the cabinet, that secures the scale for transport so it does not need recalibrating after a long drive and cannot be damaged by the trip.
If your machine lives in one bay and never moves, you do not need this feature and should not pay for it. If it goes out on a truck to customer sites, to satellite shops or around a large facility, it is the difference between a machine that stays accurate and one that is re-checked every time it arrives somewhere.
What the lock actually prevents
Two failures, and they are different. The first is damage: a scale mechanism taking road shock with an internal tank sitting on it, repeatedly, until something in it is no longer what it was. The second is drift — the quieter one, where nothing breaks but the readings are no longer trustworthy, and the machine goes on charging vehicles to a number that is subtly wrong. Locking the scale for transport addresses both, and it means the internal tank can stay on the scale during the move rather than being removed and refitted at each end.
Two supporting details show the feature was designed rather than bolted on. A safe-startup function prevents the machine powering up while the lock is still engaged, so it is not possible to run a service against a locked scale and get nonsense. And an indicator light reminds the technician to lock the scale before transport, which is the half of the procedure everybody forgets. The machine also has designated tie-down points and published guidelines for securing it in a vehicle — again, the difference between a machine that is transportable and one that is merely portable.
Built around the mobile job
Extra-long 12' hoses come as part of the same thinking. On a site visit you do not get to choose where the vehicle is parked or how close you can get the machine to it, and hose length is what decides whether a job can be done where the vehicle sits or whether it has to be moved first. Together with the tie-downs and the lock, the AC1234-4SL is specified for the shape of mobile work rather than adapted to it.
At the vehicle: what it does on its own
Operation is fully automatic — program the service, walk away, come back when it is finished — and recovery efficiency is quoted at 98.5%. The individual automations each remove a stop: internal tank refill happens automatically, so there is no pause to fill the tank during or before a service; automatic oil drain shows how much oil was taken out of the system, which is what makes the replacement quantity a measurement; and automatic air purge stops air accumulating in the internal tank rather than leaving it to be dealt with later.
An integrated refrigerant identifier samples what is in the vehicle's system before recovery begins. Programmable vacuum operation lets the evacuation be set to reach the vacuum level the conditions demand rather than running a fixed cycle, and a system leak test identifies gross leaks before the system is filled. There is also a liquid refrigerant flushing function, which cleans a system or an individual component using refrigerant in place of harsh chemicals — useful after a compressor failure has put debris through the lines.
Hybrids and high-voltage systems
The machine is specified to service both standard and high-voltage vehicle A/C systems, which matters because hybrid and electric compressors use a different, non-conductive oil and a machine that cannot keep the two apart is a liability on that work. Confirm your own oil-handling procedure for high-voltage systems alongside the machine — the capability is the machine's, the discipline is the shop's.
Perfect For
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Mobile A/C service businesses, which is the case this variant exists for.
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Fleet operations servicing vehicles on site rather than bringing them to a workshop.
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Dealer groups and multi-site shops moving one machine between locations instead of buying several.
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Large facilities and campuses where the machine travels even if it never leaves the property.
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Roadside and heavy-equipment service where the vehicle cannot come to you.
What's in the Box, and what you will re-order
The machine with the mechanical scale lock, the integrated refrigerant identifier and the 12' hose set. The printer is an option — accessory printer 30038 — rather than an inclusion. The consumables to keep on the shelf are the 34724 replacement filter and the 13172 maintenance kit; ordering the maintenance kit at the same time as the machine is the cheap way to avoid a service being held up later. Refrigerant is not supplied.
Specifications
| Model |
AC1234-4SL |
| Refrigerant |
R-1234yf |
| Recovery efficiency |
98.5% |
| Scale |
Mechanical scale lock, operated from outside the cabinet; safe-startup interlock |
| Hoses |
12 ft |
| Refrigerant identifier |
Integrated, samples before recovery |
| Vehicle systems |
Standard and high-voltage |
| Standards |
Stated to meet or exceed SAE J2843; identifier stated to meet SAE J2927 |
| Consumables |
34724 filter; 13172 maintenance kit |
| Optional |
Accessory printer 30038 |
Standards, quoted as the manufacturer states them
Robinair states that this machine meets or exceeds SAE J2843 for R-1234yf recover, recycle and recharge equipment, and that its integrated identifier meets SAE J2927. Those are the two claims in the product data and they are the two we will make. Both are performance standards for refrigerant handling — they say the machine recovers and charges to a defined accuracy and that the identifier does its job. Neither is a general equipment safety listing, and neither says anything about who is permitted to operate the machine; refrigerant-handling credentials are a separate requirement that sits with your technicians. If a contract or an insurer asks for documentation beyond these two standards, ask us before ordering and we will get it in writing rather than let this page imply it.
Shipping and Delivery
Freight to the lower 48 states. Plan the unload before delivery day — a dock, a forklift, or a terminal pickup booked with the carrier — because a machine of this weight is not a two-person lift from a truck bed however willing everybody is. Residential addresses can be delivered to and carry a residential fee, which is quoted live at checkout rather than fixed in this text. Inspect the crate with the driver still there and record any damage on the bill of lading before signing; on a machine whose scale is the thing you are buying, a knock in transit is not cosmetic.
Warranty
The manufacturer's warranty applies, with the current terms published on our warranty claims page. If a fault appears, raise it before opening anything. The scale assembly in particular is the part a warranty claim will look at first, and it is also the part most likely to be disturbed by someone taking a panel off to have a look — a machine that has been opened before the claim is filed is routinely refused. Note what the display showed, stop using the unit, and contact us.
