Technical Information, Tips, and General Information
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Accumulators / Blend Refrigerant / Cheap! / Expansion Devices / Flushing / High High-Side Pressure / Poor Cooling / Sealants / Stop Leak / Shaft Nut Missing / Temperature Testing / Tight Compressors / Warranty / Winter A/C
How can your prices possibly be so low? What's the catch?
I am asked all the time how we can possibly sell our parts so cheap. Here's the deal; do you really think the cost of a single A/C Compressor is three, four, five hundred or more dollars? With manufacturers having built so many of them over the years, don't you think that tooling is pretty much paid for, and the processes are in place to optimize time as much as possible? A Ford FS10 compressor probably costs about $50-55 to manufacture, maybe a little less even. Remember, most factories have a lot of automation as well.
So, how does the cost get to be over $200 or $300? Pretty easily; the manufacturer sells to a distributor, at a profit. The distributor sells to a warehouse, at a profit. The warehouse sells to a store, again, at a profit. The store, finally, sells to you, also at a profit. If each of those markups is 33%, you can see how the price gets higher and higher.
With the popularity of e-commerce shopping growing, many of companies have begun selling online. There are a lot of dollar signs flashing. Manufacturers and distributors see a way of cutting out some of the middle-men, and obtaining the extra profit themselves. Rather than make the same gross margins, they look at the average market price, and sell at or just below that.
Keep in mind, there is nothing wrong with either of the scenarios above. If you shop at a retail store, you have the convenience, usually, of having your item right away. You have the peace of mind of a national, or at least regional, name brand.
So what's different about TechChoice Parts? The owners, management, and most of the employees are all from manufacturers and/or distributors of A/C parts. We started this company with the goal of marketing directly to the consumer at reasonable prices. We remanufacture our own parts here at our main facility. We are a small, private company. Overhead is low, and we have no stockholders to report to. Our quality is very good, so we don't have a lot of warranty and returns to pay for. We know our parts, and pretty much just want to take care of our customers.
So, you're not paying for a bunch of middlemen. You're not paying for an office building full of people surfing the internet all day. You're not covering the cost of warranties and returns. What you are doing is getting good parts, from good people, and an affordable price.
Why do I need Air Conditioning in the Winter?
The quick answer is this: defrost. To explain further, the A/C system doesn't just cool the air, it 'conditions' it. Whether you want cold or warm conditions is your choice. The A/C system is also a dehumidifier, removing moisture from the air. Most defrosters run with the A/C system these days. Also, because most engines have a single serpetine belt driving all the accessories, a locked up compressor can cause further problems, including a broken drive belt, resulting in a stranded motorist. If you are not going to replace your locked up compressor, do not turn on your A/C or defrost.
Warranty
All of our products come with a 12 month, 12 thousand mile warranty. Each compressor is shipped with basic installation and warranty guidelines, as well as notification as to whether the compressor contains oil or not. Conditions for A/C compressor warranty are that the accumulator / receiver drier be replaced, orifice tube be replaced or expansion valve be inspected (replaced if necessary), and that the A/C system be clean. Correct amount and type of refrigerant and oil must be used.
'Tight' General Motors Compressors
GM compressors, including R4, HR6, HD6, HT6, and V5, are normally difficult to turn by hand. Each piston end has a Teflon piston ring that is pressed onto the piston. These rings 'flex' and created a positive seal in the cylinder. Similarly would be that new jar of grape jelly. Just because you can't get the lid off doesn't mean it's locked up and the jelly is bad; you just need the right tool. In the case of GM compressors, that tool is called a spanner wrench. Most auto parts stores and technicians have these.
General Motors Compressor, Shaft Nut Missing
On the subject of GM compressors...Most new GM compressors do NOT have a shaft nut. TSB number 93-T-03, GM Corp reference 261204R and 111402R, dated October 1992: Subject: "Compressor Shaft Nut Eliminated", all R4 and H6-series compressors. The details are: "Effective after July 13, 1992 for the R4 compressor or April 28, 1991 for the HR compressor, the shaft nuts were/are no longer produced for these units. This affects both production and service compressors. The elimination of this nut has been made possible by improvements in the clutch driver to compressor shaft press fit. If you receive an air conditioned vehicle with an R4 or HR compressor and there is no compressor shaft nut present, no attempt should be made to install a nut."
Poor Cooling At Idle
If you experience good cooling when driving at higher speeds, but poor cooling when stopped or at low speed, have your cooling fans or fan clutch checked. Good airflow across the condenser and radiator are important for a properly working system. Also, make sure the condenser is clean; free of bugs, debris, large plastic bags that drift up there. Blocked airflow will cause poor cooling.
Why Replace The Accumulator?
Replacing the accumulator or receiver drier is important ANY time the A/C system is opened. These parts (you have one or the other) are the main filter in the A/C system. There is a desiccant bag in every one. This bag traps debris and moisture when the system is running. When the system is opened, moisture from the air (humidity) further saturates the desiccant. When the desiccant can hold no more moisture, the moisture reacts with the refrigerant, and will create an acid that will degrade system seals.
Why Replace Orifice Tube / Expansion Valve?
Replacing orifice tubes is fairly quick and easy, and should be done any time the A/C system is serviced. The orifice tube is generally located in the condenser outlet, evaporator inlet, or sometimes in the liquid line hose assembly, particularly in Ford systems. Because orifice tubes have a fine mesh screen on them, they can easily becoming clogged. Expansion valves, located on or near the evaporator, are usually more time consuming to replace, and are not required as part of our warranty, but they should be verified for proper operation. A good technician will know, with gauge readings and temperature readings, if your expansion valve is operating correctly.
High High-Side Pressure
A bad compressor DOES NOT pump 200, 300, or 450psi. We occasionally hear from someone with an extremely high high-side reading, stating that their compressor is not working. The compressor is a pump; all it does is pump refrigerant through the system. If your high side reading is high, the compressor is working. Check temperatures at the condenser inlet and outlet (see Temperature Testing below) and gauge readings; likely restricted condenser or bad expansion device.
Temperature Testing
Temperature testing is the most effective method of verifying and diagnosing an A/C system. Gauges measure pressure. Pressure is temperature. Gauges only read at 2 points in the system; where the high and low couplers are. With a good temperature probe (search part number 13001) one can take temperature readings all over the system, and pinpoint problems. Here's how to temperature test:
AC should be set on MAX, blower on High. Doors and hood should be open. (max heat load)
There should be a minimum 30 degree drop from 1 foot in front of the condenser (front of vehicle) to the center duct in the vehicle.
There should be a 20-40 degree drop from the condenser INLET to the OUTLET. Less than 20 degrees or more than 40 degrees indicates poor airflow, improper refrigerant charge, or INTERNAL RESTRICTION. A very large temperature drop almost always indicates a restriction. The refrigerant is building up at the restriction, causing high pressure (and high heat), while little to no refrigerant is coming from the outlet, causing the big drop in temperature.
The INLET and OUTLET of the evaporator should be within 5 degrees of each other. This test is performed easiest on orifice tube systems, but if you can get to the evaporator side of the expansion valve, the test is still accurate. If the evaporator outlet is WARMER than the inlet, you have a low refrigerant charge, and need to add refrigerant. If the outlet temperature is COOLER than the inlet, there is too much refrigerant in the system. If evaporator inlet and outlet temperatures are the same, or within 5 degrees of each other, this indicates a perfectly charged A/C system.
Why Flush the System?
If your original compressor has locked up, you must flush the A/C system. Failing to do this will leave metal debris in the system, and cause the replacement compressor to fail as well. Keep in mind, new multi-pass, 6mm tube condensers are nearly impossible to properly flush. You may need to replace the condenser. Talk to your A/C Technician for more information.
Blend Refrigerants. Or, What NOT to Use.
Use only R12 or R134a refrigerant. "Blend" or "Alternative" refrigerants are not approved by ANY of the major automobile manufacturers. If those refrigerants did what they say they do, the OEMs would be all over it. Some blend refrigerants, while they may improve duct temperatures, can cause problems down the road.
System Sealant. Or, What NOT to Use Again.
Avoid system sealers and leak stop. These products are band-aids, not repairs. Leak sealers react with air. If there is air in the system, the leak stop will congeal into a thick green jelly. Not only will it clog system components, your A/C Technician is not going to want to evacuate your refrigerant with his very expensive recovery machine. Further, he will be very upset if you don't tell him you have it in your system, and he does run it through his very expensive recovery machine.
These are some basic technical facts. TechChoice Parts will be adding and updating information as it comes available, but if you have a specific question, feel free to e-mail or click "Sales Chat" for an instant online text session.