Category: Product Feature

A/C Systems – How a simple inspection can save

RedDot
Tech Tips From RedDot


Heavy-duty A/C components rarely fail. In fact, the system fails the components because of contaminated refrigerant oil and general lack of preventive maintenance.

One of the best ways to improve uptime and reduce maintenance costs for the customer is to promote a basic visual check of major A/C components, hose connections, and fittings at regular intervals, like with every engine-oil change. This inspection routine has another benefit: it can generate business for your parts and service department. 

Many A/C components are consumable items. It’s more cost-effective to replace them than to repair them. So preventive maintenance is an opportunity to sell a range of OEM-quality all-makes replacement parts for the air conditioner. Here are some examples:

1. RECEIVER DRIERS

The receiver-drier’s moisture indicator provides a quick visual cue about the refrigerant’s condition: a blue dot means the refrigerant is dry; pink, white, or grey indicates acid or moisture in the system. Checking the sight glass during an oil change or any scheduled maintenance procedure means the truck can receive necessary service while it’s there in the shop, before moisture and acid damage critical A/C components and lead to a failure on the road.

2. CONDENSERS

Dust, bugs, feathers, and other debris collect on the face of fins and tubes and act as a thermal barrier, making it hard for the condenser to shed heat. Condensers also fail because of vibration, which can cause hose connections to come loose and fatigue the condenser tubing adjacent to the fittings. Every 12 months, the condenser should be cleaned (taking special care not to bend or damage the fins) and the hose connections securely clamped.

3. COMPRESSOR/CLUTCH ASSEMBLY

The compressor provides the mechanical energy to circulate refrigerant and manipulate the pressure inside the system. It’s the heart of the A/C system, and the No. 1 HVAC maintenance expense item. Excessive noise and poor cooling performance are the two most obvious symptoms that a compressor is failing. Replacing the compressor involves pulling down the system, which adds refrigerant recovery and recharge to the repair cost.

Next time you see, “A/C won’t blow cold air” on a work order, note that the repair and downtime probably could have been avoided with a simple visual inspection of the truck’s air conditioning system. Any time you change the truck’s oil, check the A/C.

Eberspacher Technician Certification

As an authorized Master Distributor, ATC recently hosted a Certified Technician Training course for our southern Ontario dealers, with Eberspachers Training Manager George Lenus. The class on the newly released state of the art #HydronicS3 engine coolant heater was well attended and helped demonstrate our commitment to our dealers and technical excellence.
Arctic Traveler hosts Certified Technician Training by Eberspacher

ESPAR Hydronics Heaters – Preseason Maintenance

Arctic Traveler Canada is a master distributor and technical service expert for ESPAR Airtronics and Hydronics Heaters.
Recommended Pre-Season Maintenance For HYDRONIC Heaters 

Before the cold weather arrives, it is recommended that your HYDRONIC 4 / 5 or 10 heaters receive a preseason check. Please use the recommended tools and follow the procedures as outlined in the heater manual while removing and reinstalling the different heater components. Pre‐season maintenance will make sure that your heater(s) are clean, free running and ready for a trouble free season.

The heaters should be inspected and repaired by an Espar trained mechanic, as follows:
1. Check all electrical connections from the heater to the batteries. Check for wear and abrasion along the length of the harnesses. Repair or replace the harness whenever the harness insulation is broken or damaged. Check the battery connections. Clean any corrosion at the terminals. Replace the battery terminals if the corrosion is severe. Check the fuse for corrosion and the correct rating.

2. Check all clamps and hoses. Replace as required.

3. Check the condition of the exhaust system. Check for holes and breaks in the exhaust piping. Replace the exhaust as necessary.

4. Check the fuel pump filter ‐ clean or replace as necessary. For heaters with external fuel pumps, ensure mounting angle of the fuel pump is in between 15‐35o. An incorrectly mounted fuel pump may lead to excessive carbon issues. Check the fuel lines for possible leaks, loose clamps, etc. Once the entire fuel system has been checked and any issues corrected, it is advisable to do a fuel quantity check.

5. Check and clear clogged weep holes on the side of the heater body. Look for any indication of coolant leakages. If leakage is suspected then remove cover with water pump assembly and inspect and replace “O” rings on water pump housing. Closely inspect the heater waterjacket for leakages and replace “O” ring between waterjacket and heat exchanger. If the waterjacket is cracked, replace it.

6. Remove and replace the glow pin screen. Make sure that the new screen is installed correctly as outlined in the repair manual for the heater.

7. Remove and check the glow pin. If it shows signs of dissimilar color or if the glow pin is in any way distorted, replace it.

8. The coolant pump should be removed and the impeller checked for damage. Any dirt or metal particles on the impeller magnet should be removed and the cavity in the pump should also be cleaned. Please Note: coolant pumps are not covered by warranty if the vehicle’s coolant system is excessively contaminated. Refer to Technical Circular 250.

9. Remove the flame tube and check the condition of the flame tube end. The flame tube should be light brown in color with no excessive carbon on the end of the flame tube. Check for carbon build up on the burner “nose” at the cold end of the flame tube. Any carbon covering the air slots should be removed. Check the inside of the heat exchanger and scrape any loose carbon out from between the fins in the heat exchanger. Re‐install the flame tube replacing all gaskets.

10. Re‐assemble the heater and test operation. The heater should be bench tested for 15‐20 minutes before returning the heater to the vehicle.

11. Regardless of the season, run the heater every month for a minimum period of 15 minutes. This will help the heater to burn away any combustion residue in the burner chamber and prevent corrosion in the waterjacket and decay of “O”rings.

ESPAR Airtronics Heaters – Preseason Maintenance

Arctic Traveler Canada is a master distributor and technical service expert for ESPAR Airtronics and Hydronics Heaters.

Recommended Pre-Season Maintenance For AIRTRONIC Heaters 
It is recommended that the AIRTRONIC heaters receive a pre-season check-up to make sure that the heaters are ready for a trouble-free cold weather season. Always use the recommended tools and follow the procedures as outlined in the manual while removing and reinstalling the heater components. 

The heaters should be inspected and repaired by an Espar trained mechanic, as follows:
1. Before initial operation ensure that the heater is not being subjected to external loads by heavy objects being placed over it. This may cause damage to the heater parts and affect its normal operation. Ensure that sufficient clearances, as recommended in the heater manual are being maintained around the heater, even while the vehicle is in operation.

2. Check the return air inlet port and hot air outlet port for any blockages. Inspect the length of ducting for any damage and replace as necessary. Ensure all ducting connections are secure. Discourage heat sensitive materials from being placed too close to the heater, ducting components or hot air outlet ports.

3. Check all electrical connections from the heater to the batteries. Check for wear and abrasion along the length of the harnesses. Repair or replace the harness whenever the harness insulation is broken or damaged. Check the battery connections. Clean any corrosion at the terminals. Replace the battery terminals if the corrosion is severe. Check the fuse for corrosion and the correct rating.

4. Remove the glow pin and if necessary, clean it. If the glow pin shows signs of dissimilar color or distortions, replace it. Inspect the glow pin wires for damage and if necessary, replace it. Remember to clean the glow pin chamber and ensure glow pin ventilation hole is clear of any obstructions, than replace the glow pin.

5. Regardless of its condition, remove and replace the glow pin screen every pre-season. Make sure that the new screen is installed correctly. Install the new screen.

6. Check the condition of the exhaust pipe. Look for any holes or breaks in the exhaust piping. Replace if necessary. Ensure the exhaust pipe is securely located and correctly routed.

7. Check the condition of the combustion air intake tube. Clear any blockages. If damaged, replace it. Ensure that the combustion air intake tube is securely located and correctly routed.

8. Ensure mounting angle of the fuel pump is in between 15-35 degrees. An incorrectly mounted fuel pump may lead to excessive carbon issues. Check the fuel lines for possible leaks, loosened clamps, etc., inspect the filter on the suction side fuel pump filter, clean or replace as necessary. Once the entire fuel system has been checked and any issues corrected, it is advisable to do a fuel quantity check.

9. If the fuel quantity result is above specification, then it will be a cause for excessive carbon issues and the fuel pump should be replaced. If the fuel quantity result is within specifications, but on the higher side, then any possible excessive carbon issues may be corrected by increasing the mounting angel of the fuel pump to the near vertical position. If fuel quantity result is below specification, then it is recommended that the fuel pump may be replaced only if the heater repeatedly flames out during operation.

10. If there are complaints about the heater smoking excessively during operation then remove and check the condition of the burner. The burner should be light brown in color. Clean any carbon build up inside the burner tube. Check the inside of the heat exchanger and scrape out any loose carbon.

11. When reassembling the burner and the heat exchanger use a new thermal insulator. Likewise, when reassembling the blower motor assembly use a new blower gasket.

12. Reassemble the heater and test operation. The heater should be bench tested for 15-20 minutes before returning the heater to the vehicle.

13. Regardless of the season, run the heater every month for a minimum period of 15 minutes. This will help the heater to burn away any combustion residue in the burner chamber. It will ensure that the fuel in the lines to the heater does not gel and solidify and that the heater will start reliably when heating season arrives.

How to inspect an A/C Compressor

Before you pull the A/C compressor from a heavy-duty vehicle, take these steps to confirm that it really needs replacing:

1. Is The Compressor Rotation Smooth?
With the vehicle off, turn the compressor shaft with a 14-mm socket. If you feel grinding or hanging as you rotate the shaft, it’s probably due to broken components within the compressor. If the rotation is smooth, move on to Step 2.
2. Is The Coil Getting More Than 11.5 Volts?
Take a reading with the engine running and the clutch engaged. If there’s insufficient voltage, get to work on that. Otherwise, move on to Step 3.
3. Is The Coil Resistance Between 2.8 And 4.4 Ohms?
Any resistance outside this range will prevent the clutch from engaging or will cause used circuits to open. If the answer is yes, continue to Step 4.
4. Is The Compressor Able To Produce 350 Psig Or More?
If not, leave the compressor where it is. The system may have a low refrigerant charge because of a leak that needs repair, or a high-side blockage that limits refrigerant flow to the compressor.

Tech Tips from Red Dot
” We see lots of compressors that are returned fully functional and therefore not warrantable.
Get the diagnosis right. Perform a simple compressor function check before you pull the component from the vehicle.”

How to troubleshoot your A/C Electrical system

Tech Tips from Red Dot

On any vehicle, and virtually any system, electrical problems are among the hardest to troubleshoot. If you suspect an electrical problem with the A/C system, here’s a two-stage inspection routine that virtually anyone can do with no special tools or skills:

1. Inspect Electrical Connections

As you perform a visual inspection under the hood (cab) and/or at the rooftop condenser, take a moment to check all electrical connections both visually and by feel. Make sure all leads and wires are properly supported and securely connected, and that there’s no corrosion or grime on the leads or connectors.

2. Check Electrical Current Flow and Device Functions

Perform the following steps to check current flow and electrical device functions:

  • Turn on the ignition. 
  • Turn on the A/C system. This will power the thermostat and clutch. If it does not come on, use the A/C mode switch to check the leads to the switch. You should hear a “click” from the thermostat and hear the clutch drive plate “snap” against the clutch pulley. 
  • Check fuses. If all the connections are clean and tight and there’s still a failure, check the fuses in-cab as well as in-line.
  • Check A/C clutch engagement. Since you can’t see and may not hear the clutch engage, get out and look at the clutch. If it’s engaged, you will see that the drive plate is against the pulley and not slightly spaced from it. If you aren’t sure the clutch is engaged, look for the lead wire connector near the clutch. Break and close that connection. The clutch will disengage and engage again.
  • Test blower speed operation. Some systems have a common switch that turns on the air conditioner and powers the blower motor. Test blower speed operation by adjusting this or the separate blower control switch. Feeling the air flow from the ducts or note blower sound (speed) changes.
  • Inspect roof-mounted condensers. Don’t forget to inspect roof-mounted condensers and A/C units for dirt and debris. Be sure the condenser fan(s) are working properly and all parts and electrical connections are securely fastened. The roof-mounted condenser fans may come on when the system is turned on. Like the thermostat and most clutches, the normal on-off cycling action can not be observed until the engine is running with the A/C system on.

Once your visual inspection is complete, talk to a qualified A/C technician about what you found. Your troubleshooting efforts will be rewarded with a speedier repair and perhaps a lower repair bill.