Hello again, Readers!
I was polishing up an article on a completely different subject - and no, not A/C! - when I was inspired to write and publish this one instead. Several customers came in asking for 'brakes' for their vehicles, but gave me the deer-in-the-headlights look when I asked the usual questions. After supplying the auto's details (year, make, model), they were lucky if they knew whether they needed them for the front or the back!
Before I continue, please make a note of this: The word "brakes" refers to the *entire* brake system of your auto. If you are only after 'brake pads' or 'brake shoes', you will need to use those specific terms. If you ask for a price on "brakes", you will likely get a quote for at least your rotors (or drums) as well. And as you will soon see, there IS a difference between 'pads' and 'shoes'!
I will now endeavor to name and explain the main brake system components.
Master Cylinder: This piece is located under the hood, on the driver's side, up against the firewall. Have you ever checked the brake fluid level on your vehicle? That tank (or 'reservoir') you checked is mounted to the top of the master cylinder. When you push the brake pedal, the master cylinder pushes the fluid through the lines and hoses, activating the brake systems at all four wheels.
NOTE: There is a LOT more to the brake hydraulics system topic,
but we will discuss that further in another edition.
Disc Brake System - Used on the front of all modern vehicles, and increasingly on the back as well.
Brake Rotor: This is shaped like a top-hat. The 'brim' is the friction-surface area, which is squeezed by the pads when you want to slow down/stop. The 'crown' (middle portion) sticks up/out further to mount the rotor onto the vehicle, then receive the wheel onto it. Rotors are sold 'per wheel'; there are 2 'per axle'.
NOTE: Some rotors are 'Rotor/Hub Assemblies', which means they
will have the wheel studs made onto them already. The rest
of them will have holes that line up with the studs that are
already on the vehicle. Just be aware!
Caliper: This is mounted at the top of the rotor, either towards the front edge or the back edge. It may remind you of a hand in a 'grabbing claw' position. It is anchored in place behind the rotor via a mounting bracket, The caliper holds 2 brake pads, 1 on each side of the rotor. The caliper has a hydraulically-moved piston on the 'inboard' side, which causes the pads to move. Calipers are also sold 'per wheel'.
NOTE: Loaded = w/ hardware & pads;
Semi-loaded/Friction-ready = w/ hardware;
Bare = caliper only
In all cases, be sure to ask if the mounting bracket comes with it!
Pads: These are the 'brake wear linings' on a Disc Brake system. They have a flat, semi-thick (maybe 1/4") metal backing plate, with a very thick (~1") form of baked-powder wearing material. The wearing material may or may not have a 'slot' (dividing groove) somewhere in the middle. (Some go vertically, others diagonally.) The pads fit inside the caliper housing. The wearing material ALWAYS faces the rotor's 'brim', sandwiching the rotor like an Oreo cookie. When the caliper piston sticks out, it forces the pads to squeeze the 'brim', which slows/stops the vehicle. Pads are sold 'per axle', 4 in a box.
NOTE: Most of the time - especially on the front axle - the 'inboard' pad
will look differently than the 'outboard' pad. If you see a set of
pads, and they seam to be two different pairs, that is probably
okay! If they seem to be a 4-of-a-kind (mostly on rear axles that
take disc brakes), then inboard/outboard does not matter.
Drum Brake System - Used on the rear of many modern vehicles, but also on the front of vehicles until about the early-to-mid 1970's.
Brake Drum: Whereas the Rotor was a top-hat, the Drum resembles more of a cake-pan. The inside wall of the pan is the friction-surface area. The shoes push out to rub against the front ("leading") and rear ("trailing") edges to help slow/stop the automobile. Unlike the disc system, you cannot see all of the major components from 'curbside'. Drums are sold 'per wheel'; there are 2 'per axle'.
NOTE: The vast majority of drums will have holes to receive the wheel
studs, as opposed to having the studs made onto them. Unless
you have a Medium-Duty truck or something similar - like the
ones that get turned into ambulances, dump trucks and such -
this won't really concern you.
Shoes: These are the 'brake wear linings' on a Drum Brake system. Again, they start with a metal backing plate, then add a baked-powder wearing material on the friction surface side. BUT, whereas pads are flat, shoes literally resemble a 'crescent moon'. The shoes both fit INSIDE the cake-pan - and yes, 'leading' and 'trailing' positions DO matter! A bunch of hardware (mostly springs) hold them in place, guide their movements and return them to their original position. As with pads, these are sold 'per axle', 4 in a box.
NOTE: The drum hardware resembles a complicated jigsaw puzzle when
assembled. Most technicians/mechanics do one side at a time,
using the other side as a reference picture. Yes, it's that confusing!
Wheel Cylinders: These tiny things are the drum system's equivalent of the caliper. There isn't a good non-automotive analogy readily available. The best I can do, is compare it to a chicken egg. Imagine a 'grade A large' egg, with the ends made out of rubber, and the middle made out of metal (steel and/or aluminum alloy). Now, stretch the middle a bit in length, until it resembles more of a tube with rounded ends. In the rubber ends, you see a metal screw/piston protruding slightly from each side. And on the top of the metal body, there are two threaded holes - one has an odd-headed screw in it. The slotted pistons are what force the shoes out against the inside walls of the drum. Sold 'per wheel', there are 2 wheel cylinders per axle.
There you have it: the primary components of automotive brake systems. We'll revisit this subject again soon, so we can go over the secondary components. By then, I hope to have a nice collection of photos of these pieces, so you can literally see what I mean. I just have to find the opportunity to take pictures of my stock parts at work! Then, I get to figure out the particulars on how Blogger wants me to add them. Sounds like an adventure to me!
Until next time, remember the Golden Rule... Not only good for people, but your auto, too!
PPM
26 July 2012
12 July 2012
"Freon" names: Not 'just a number'!
Welcome back, Readers!
Since our last gathering, the refrigerant (or as many say, "freon") sales at my store have remained incredibly high. Given our weather this hot summer season, that's not at all surprising. But we also *still* get a large portion of customers who don't know which refrigerant their vehicle takes, or why it even matters. If it wasn't so dangerous to confuse them all, we (store employees) wouldn't have a panic attack every time someone tried to mix them. [Cue "Home Alone" scream: Aaaaaaagggggghhhhhhh!!!!]
First things first: It's called "refrigerant", not "freon".
But, I suppose that misnomer will never really change. I liken that to all 'flying disc toys' being called 'Frisbees' (even if not made by the Frisbee toy company). Or Southerners calling all sodas/colas/pop "Coke"... then clarifying "Pepsi", "7-Up", "Diet Coke", etc. for someone's specific carbonated drink choice. When a product reaches a certain popularity level, it tends to be the 'face and name' of the category it represents. Since the refrigerant named R12 was commonly known as "freon", that moniker has also been applied to other refrigerants.
Good to note: The many refrigerants that exist.
Just off the top of my head, I can name 3 refrigerants: R12, R22 and R134a. I'm quite certain others exist, but for the purposes of this article we only need to mention these three.
R22 is NOT an automotive grade of refrigerant. It's use is primarily confined to refrigerator/freezer units. (Yes, as in cold food storage!) I am not certain, but R22 may have also been used in A/C units for buildings. I know *some* type of refrigerant is used, either R22 or its replacement. Actually, I believe R22 is being phased out (like R12 is for automobiles), though I don't recall what is replacing it, nor when that actually started. But, this is an automotive blog, so I'll let you research that one on your own. :-)
R12 (aka "Freon"): This refrigerant was used in the A/C systems for ALL U.S.A.-bound vehicles, through Model Year 1992. (Europe may have switched away from R12 even earlier, but I do not recall.) If you remember having a family car with A/C during the 1980's, you probably also remember the way it would darn near freeze your skin off. Ah, refreshing! Right? But, R12 was soon discovered for being a *huge* culprit in destroying Earth's protective Ozone layer. So, it had to go. And we replaced it with...
R134a: This refrigerant came on to the scene like a superhero, ready to replace that environmental villain called R12. Starting in Model Year 1994, R12 was completely banned from usage. R134a was the ONLY acceptable refrigerant for automobiles. Okay, maybe the R134a stuff doesn't freeze your skin off the way R12 did (IF you're old enough to really remember the difference!), but at least we aren't killing our planet like we were before.
[SIDEBAR: R134a, while better than R12, is also causing problems with our climate. Beginning in 2011, Europe is banning R134a (aka HFC-134a) from being used in all new cars. The proposed substitute is HFO-1234yf, which is reportedly compatible with R134. They get along nicely, so there is no fear about mixing them. But, we can discuss that new refrigerant when it actually hits the U.S.A.'s market. Word is, select Chevy models will have it in MY2013. See for yourself on Wiki: http://en.wikipedia.org/wiki/HFO-1234yf.]
Hey, you skipped Model Year 1993!
Thanks for speaking up! Kudos to you for paying attention and catching that!
Here's the deal: From MY1992 through MY1993, vehicle manufacturers were able to use up remaining components for R12 systems in a 'phase out' method. Once they started production on MY1994 vehicles, they *had* to be completely using R134a components and refrigerant. Every manufacturer seemed to take a different approach to the phase-based transition. Some opted to start certain factories as early as 1992, while others picked different transition points in MY1993. I think some even waited until the very first MY1994 auto to launch the R134a systems. I'm sure they all had their own reasons for the strategies they chose.
How to tell which refrigerant your vehicle takes:
1. What model year is it?
a. 1994 and newer: From the factory w/ R134a
b. 1992-93: Check the sticker (see below for details).
c. 1991 and older: From the factory w/ R12, but may have been changed. Check the sticker.
2. What does the sticker say?
a. Lift your hood and prop it up, if needed.
b. Look for the sticker/decal that says "This vehicle conforms to XXXX model year emissions standards..."
c. On that same decal, it should mention whether the factory put in R12 or R134a refrigerant.
d. If that decal said R12, look around to see if there is another, newer sticker saying "Retrofitted on [date]. If so, yours has been changed to R134a.
3. What do the caps of the fittings look like?
a. Take a quick look at one of your tires. Look at the valve stem (where you add air and check the pressure) and make a mental note of what that cap looks like. It will be plastic, black (or maybe green).
b. Now go back to your engine compartment. Glance around the top perimeter. Do you see anything that looks like your valve stem's cap? If so, that's an R12 fitting. Don't see it? Keep reading!
c. Keep looking around the top perimeter (picture frame of the under-hood area). Do you see any fittings with a red or blue cap? This will be closer to the diameter of a nickel or a quarter. If you see one of these (they are sometimes in hard-to-find areas, even at the bottom of the engine), then you have R134a.
4. If you get frustrated, by all means ask someone to help you! A fresh set of eyeballs alone may be all you need. Otherwise, pull out your owner's manual (they should at least mention where the low side is), a repair manual, or go to your friendly quality auto parts store. They won't put the refrigerant in for you, but they *will* help you to identify which kind you need.
WARNING: R12 + R134a = *HUGE* POTENTIAL FOR EXPLOSION!!!
You've heard of the major feud between the Hatfields and the McCoys, right? Well, these two refrigerant gases are exponentially worse when mixed together! Seriously! So, please, if you are ever in doubt, just turn the task over to a professional. It is *not* worth risking the lives and limbs of you and everyone around you, just to save a few dollars.
A Quick Word on Retrofitting...
Retrofitting is when an R12 system is converted over to an R134a-compatible system. The *last* step of this process is to attach 'adapter fittings' to the old R12 fittings. But, the first step is to have all remaining traces of R12 vacuumed out by a special machine. And only someone with a license can do that, so you MUST go to a licensed repair shop to have that done.
Yes, 'Retrofit Kits' are available in stores. Yes, my store sells them also (currently around $60 + tax). Yes, you can technically purchase one of these kits (which include the adapter fittings) and install it yourself. They do seem to have pretty clear step-by-step directions on the package.
BUT
No, I will not provide those kinds of directions on this blog. No, I will not recommend nor endorse that an unlicensed DIY'er uses such a kit to update an R12 system. In fact, if someone comes in to purchase such a kit, then has to ask how to use it, I generally direct them to have a shop do it. It is safer for the customer, their friends, their neighbors - truly, EVERYONE - that way.
As they say, "buyer beware".
That covers another sizable lesson for today. Hey, air conditioning is a sizable topic! But now you are better equipped to know which refrigerant you need, why you can't mix them, and when to raise the white flag that says "I need help".
Until next time, remember the Golden Rule... not only good for people, but your auto too!
-PPM
Since our last gathering, the refrigerant (or as many say, "freon") sales at my store have remained incredibly high. Given our weather this hot summer season, that's not at all surprising. But we also *still* get a large portion of customers who don't know which refrigerant their vehicle takes, or why it even matters. If it wasn't so dangerous to confuse them all, we (store employees) wouldn't have a panic attack every time someone tried to mix them. [Cue "Home Alone" scream: Aaaaaaagggggghhhhhhh!!!!]
First things first: It's called "refrigerant", not "freon".
But, I suppose that misnomer will never really change. I liken that to all 'flying disc toys' being called 'Frisbees' (even if not made by the Frisbee toy company). Or Southerners calling all sodas/colas/pop "Coke"... then clarifying "Pepsi", "7-Up", "Diet Coke", etc. for someone's specific carbonated drink choice. When a product reaches a certain popularity level, it tends to be the 'face and name' of the category it represents. Since the refrigerant named R12 was commonly known as "freon", that moniker has also been applied to other refrigerants.
Good to note: The many refrigerants that exist.
Just off the top of my head, I can name 3 refrigerants: R12, R22 and R134a. I'm quite certain others exist, but for the purposes of this article we only need to mention these three.
R22 is NOT an automotive grade of refrigerant. It's use is primarily confined to refrigerator/freezer units. (Yes, as in cold food storage!) I am not certain, but R22 may have also been used in A/C units for buildings. I know *some* type of refrigerant is used, either R22 or its replacement. Actually, I believe R22 is being phased out (like R12 is for automobiles), though I don't recall what is replacing it, nor when that actually started. But, this is an automotive blog, so I'll let you research that one on your own. :-)
R12 (aka "Freon"): This refrigerant was used in the A/C systems for ALL U.S.A.-bound vehicles, through Model Year 1992. (Europe may have switched away from R12 even earlier, but I do not recall.) If you remember having a family car with A/C during the 1980's, you probably also remember the way it would darn near freeze your skin off. Ah, refreshing! Right? But, R12 was soon discovered for being a *huge* culprit in destroying Earth's protective Ozone layer. So, it had to go. And we replaced it with...
R134a: This refrigerant came on to the scene like a superhero, ready to replace that environmental villain called R12. Starting in Model Year 1994, R12 was completely banned from usage. R134a was the ONLY acceptable refrigerant for automobiles. Okay, maybe the R134a stuff doesn't freeze your skin off the way R12 did (IF you're old enough to really remember the difference!), but at least we aren't killing our planet like we were before.
[SIDEBAR: R134a, while better than R12, is also causing problems with our climate. Beginning in 2011, Europe is banning R134a (aka HFC-134a) from being used in all new cars. The proposed substitute is HFO-1234yf, which is reportedly compatible with R134. They get along nicely, so there is no fear about mixing them. But, we can discuss that new refrigerant when it actually hits the U.S.A.'s market. Word is, select Chevy models will have it in MY2013. See for yourself on Wiki: http://en.wikipedia.org/wiki/HFO-1234yf.]
Hey, you skipped Model Year 1993!
Thanks for speaking up! Kudos to you for paying attention and catching that!
Here's the deal: From MY1992 through MY1993, vehicle manufacturers were able to use up remaining components for R12 systems in a 'phase out' method. Once they started production on MY1994 vehicles, they *had* to be completely using R134a components and refrigerant. Every manufacturer seemed to take a different approach to the phase-based transition. Some opted to start certain factories as early as 1992, while others picked different transition points in MY1993. I think some even waited until the very first MY1994 auto to launch the R134a systems. I'm sure they all had their own reasons for the strategies they chose.
How to tell which refrigerant your vehicle takes:
1. What model year is it?
a. 1994 and newer: From the factory w/ R134a
b. 1992-93: Check the sticker (see below for details).
c. 1991 and older: From the factory w/ R12, but may have been changed. Check the sticker.
2. What does the sticker say?
a. Lift your hood and prop it up, if needed.
b. Look for the sticker/decal that says "This vehicle conforms to XXXX model year emissions standards..."
c. On that same decal, it should mention whether the factory put in R12 or R134a refrigerant.
d. If that decal said R12, look around to see if there is another, newer sticker saying "Retrofitted on [date]. If so, yours has been changed to R134a.
3. What do the caps of the fittings look like?
a. Take a quick look at one of your tires. Look at the valve stem (where you add air and check the pressure) and make a mental note of what that cap looks like. It will be plastic, black (or maybe green).
b. Now go back to your engine compartment. Glance around the top perimeter. Do you see anything that looks like your valve stem's cap? If so, that's an R12 fitting. Don't see it? Keep reading!
c. Keep looking around the top perimeter (picture frame of the under-hood area). Do you see any fittings with a red or blue cap? This will be closer to the diameter of a nickel or a quarter. If you see one of these (they are sometimes in hard-to-find areas, even at the bottom of the engine), then you have R134a.
4. If you get frustrated, by all means ask someone to help you! A fresh set of eyeballs alone may be all you need. Otherwise, pull out your owner's manual (they should at least mention where the low side is), a repair manual, or go to your friendly quality auto parts store. They won't put the refrigerant in for you, but they *will* help you to identify which kind you need.
WARNING: R12 + R134a = *HUGE* POTENTIAL FOR EXPLOSION!!!
You've heard of the major feud between the Hatfields and the McCoys, right? Well, these two refrigerant gases are exponentially worse when mixed together! Seriously! So, please, if you are ever in doubt, just turn the task over to a professional. It is *not* worth risking the lives and limbs of you and everyone around you, just to save a few dollars.
A Quick Word on Retrofitting...
Retrofitting is when an R12 system is converted over to an R134a-compatible system. The *last* step of this process is to attach 'adapter fittings' to the old R12 fittings. But, the first step is to have all remaining traces of R12 vacuumed out by a special machine. And only someone with a license can do that, so you MUST go to a licensed repair shop to have that done.
Yes, 'Retrofit Kits' are available in stores. Yes, my store sells them also (currently around $60 + tax). Yes, you can technically purchase one of these kits (which include the adapter fittings) and install it yourself. They do seem to have pretty clear step-by-step directions on the package.
BUT
No, I will not provide those kinds of directions on this blog. No, I will not recommend nor endorse that an unlicensed DIY'er uses such a kit to update an R12 system. In fact, if someone comes in to purchase such a kit, then has to ask how to use it, I generally direct them to have a shop do it. It is safer for the customer, their friends, their neighbors - truly, EVERYONE - that way.
As they say, "buyer beware".
That covers another sizable lesson for today. Hey, air conditioning is a sizable topic! But now you are better equipped to know which refrigerant you need, why you can't mix them, and when to raise the white flag that says "I need help".
Until next time, remember the Golden Rule... not only good for people, but your auto too!
-PPM
05 July 2012
A Primer on Automotive A/C
Hello, again, Readers!
I hope all of you had a safe and fun 4th of July! With the vast majority of the USA having temperatures in (or flirting with) triple-digits, air conditioning (A/C) systems are a hot topic right now. [No pun intended.] If your vehicle's A/C system doesn't cool you off the way you think it should, then you should have it checked out, pronto!
TIME OUT!
Did my last statement put you in panic mode, as you saw a herd of dollar signs do a flash-mob fly-by? Yes, A/C service and repair *can* be very expensive. And the less you know about the topic, the easier it is for you to feel like you're being scammed. I get it! So, let me try to give you a (hopefully brief!) primer on the matter.
[Cue Zach Morris:] TIME IN!
Let's start at the very beginning... (a very fine place to start...)
A/C stands for Air *Conditioning*
The way your A/C system works:
1. Draws the (hot/warm) air already in the cabin - where the occupants are - into the A/C circuit.
2. Pushes the hot/warm air through the various hoses and 'stops', reducing the temperature and moisture as it goes.
3. Cycle the cooled-down, drier (read: conditioned) air back to the cabin, where the occupants happily reap the benefits.
"But my A/C doesn't feel very cold!"
Well, that is probably very true. So, the question is whether the problem is with the system or with your perception. Hmm...
You don't need to go to any repair shop to check this out yourself. All you need is an automotive a/c thermometer, available at most decent (and even the not-so-decent) parts stores. It will look a lot like a regular cooking thermometer (you know, the ones you use to check cooked foods for temperature doneness), though some have dials that are as big as 2" in diameter - to make it easier to read quickly. In fact, a spare cooking thermometer will work just fine. (My hubby and I have used one before ourselves, since we always have 3 or 4 on hand from his culinary days.)
What you do:
1. Take the thermometer with it's case out to your auto. Remove it from the case (storage sleeve) and slip it through the holding loop at the top.
2. Stick the probe end into one of the A/C vents. Give it a moment, then read the current temperature (which is the 'ambient' or 'room' temperature of the cabin) as reported by the thermometer.
3. Start your vehicle, turn on your A/C system to the coldest setting and on 'MAX A/C' (which is the hardest it will push the conditioned air).
4. Watch the dial on the thermometer as it moves. Depending on the status of your auto and its A/C system, you should notice a drop of between 5 and 15 degrees Fahrenheit (or maybe even more).
Question: If the local weather channel says it's 90+ outside - so, 100+ in the vehicle - do you think a 5 to 15 degree drop will be very noticeable to you?
Your A/C system is a closed circuit, designed to 'condition' the air from your (assumed to be) closed cabin. If all of your windows and doors are closed and properly sealed, then the A/C system will first work to cool the original cabin air by 5-15 degrees. Once all of that air has been circulated and 'conditioned', the system will work to cool it down by *another* 5-15 degrees.
Example:
Your parked car has a cabin temperature of 100 degrees when you get in. You crank the A/C on, which progressively conditions all of the original air down to 85 (if 15 degree drop) to 95 (5 degree drop). Once that is done - and assuming you leave the A/C on - the system will continue to work on the air for another round, drawing it down to 70 (if 15 degree drop) to 90 (5 degree drop).
Depending on the efficiency of your vehicle's system, it may take almost 2 to 3 or 4 cycles for you 'to feel the cold'. Sobering thought, right?
"Is it busted?"
That depends on what your test results showed.
If the drop was consistently 15 degrees, you simply need to adjust your perceptions, taking into account the ambient temperature and what you've learned in this article.
If the drop was consistently 5 degrees - even on the MAX A/C setting - that is a problem, but probably not a major one. You may simply need an "A/C Evac(uation) and Recharge", which I believe most shops are quoting for well under $100 out-the-door. (I heard one of the national-chain stores we service quoting $69 plus tax and shop fees.)
Now, if the poor performance was because you were *low* on refrigerant, I want you to remember something very important: The A/C system is a *closed* circuit. Therefor, being low means at least some of it leaked out. Where the leak source is, will determine how pricey the repair bill will be. But we'll discuss that in the next edition.
Alright, loyal Readers, that should be enough to get you started in the right direction. Yes, the heat and humidity can make it incredibly hard to be patient and objective, especially when you feel like screaming, "All I want is for my car to keep me cool!" It is my hope that I have given you enough information, to at least hold off on panicking until you can see if the situation truly warrants it.
Until we meet again, try to stay cool... and remember that your vehicle also deserves the Golden Rule.
PPM
P.S.: Yes, the Zach Morris mention was a "Saved by the Bell" reference. Kudos if you caught that!
I hope all of you had a safe and fun 4th of July! With the vast majority of the USA having temperatures in (or flirting with) triple-digits, air conditioning (A/C) systems are a hot topic right now. [No pun intended.] If your vehicle's A/C system doesn't cool you off the way you think it should, then you should have it checked out, pronto!
TIME OUT!
Did my last statement put you in panic mode, as you saw a herd of dollar signs do a flash-mob fly-by? Yes, A/C service and repair *can* be very expensive. And the less you know about the topic, the easier it is for you to feel like you're being scammed. I get it! So, let me try to give you a (hopefully brief!) primer on the matter.
[Cue Zach Morris:] TIME IN!
Let's start at the very beginning... (a very fine place to start...)
A/C stands for Air *Conditioning*
The way your A/C system works:
1. Draws the (hot/warm) air already in the cabin - where the occupants are - into the A/C circuit.
2. Pushes the hot/warm air through the various hoses and 'stops', reducing the temperature and moisture as it goes.
3. Cycle the cooled-down, drier (read: conditioned) air back to the cabin, where the occupants happily reap the benefits.
"But my A/C doesn't feel very cold!"
Well, that is probably very true. So, the question is whether the problem is with the system or with your perception. Hmm...
You don't need to go to any repair shop to check this out yourself. All you need is an automotive a/c thermometer, available at most decent (and even the not-so-decent) parts stores. It will look a lot like a regular cooking thermometer (you know, the ones you use to check cooked foods for temperature doneness), though some have dials that are as big as 2" in diameter - to make it easier to read quickly. In fact, a spare cooking thermometer will work just fine. (My hubby and I have used one before ourselves, since we always have 3 or 4 on hand from his culinary days.)
What you do:
1. Take the thermometer with it's case out to your auto. Remove it from the case (storage sleeve) and slip it through the holding loop at the top.
2. Stick the probe end into one of the A/C vents. Give it a moment, then read the current temperature (which is the 'ambient' or 'room' temperature of the cabin) as reported by the thermometer.
3. Start your vehicle, turn on your A/C system to the coldest setting and on 'MAX A/C' (which is the hardest it will push the conditioned air).
4. Watch the dial on the thermometer as it moves. Depending on the status of your auto and its A/C system, you should notice a drop of between 5 and 15 degrees Fahrenheit (or maybe even more).
NOTE: Remember that a closed-up car will always get hotter than the outside air! If it's 90 outside, don't be surprised if the car is more like 100+, especially if it's been in direct sunlight. Hence all the warnings about leaving kids and/or pets in parked cars...
Question: If the local weather channel says it's 90+ outside - so, 100+ in the vehicle - do you think a 5 to 15 degree drop will be very noticeable to you?
Your A/C system is a closed circuit, designed to 'condition' the air from your (assumed to be) closed cabin. If all of your windows and doors are closed and properly sealed, then the A/C system will first work to cool the original cabin air by 5-15 degrees. Once all of that air has been circulated and 'conditioned', the system will work to cool it down by *another* 5-15 degrees.
Example:
Your parked car has a cabin temperature of 100 degrees when you get in. You crank the A/C on, which progressively conditions all of the original air down to 85 (if 15 degree drop) to 95 (5 degree drop). Once that is done - and assuming you leave the A/C on - the system will continue to work on the air for another round, drawing it down to 70 (if 15 degree drop) to 90 (5 degree drop).
Depending on the efficiency of your vehicle's system, it may take almost 2 to 3 or 4 cycles for you 'to feel the cold'. Sobering thought, right?
"Is it busted?"
That depends on what your test results showed.
If the drop was consistently 15 degrees, you simply need to adjust your perceptions, taking into account the ambient temperature and what you've learned in this article.
If the drop was consistently 5 degrees - even on the MAX A/C setting - that is a problem, but probably not a major one. You may simply need an "A/C Evac(uation) and Recharge", which I believe most shops are quoting for well under $100 out-the-door. (I heard one of the national-chain stores we service quoting $69 plus tax and shop fees.)
Now, if the poor performance was because you were *low* on refrigerant, I want you to remember something very important: The A/C system is a *closed* circuit. Therefor, being low means at least some of it leaked out. Where the leak source is, will determine how pricey the repair bill will be. But we'll discuss that in the next edition.
Alright, loyal Readers, that should be enough to get you started in the right direction. Yes, the heat and humidity can make it incredibly hard to be patient and objective, especially when you feel like screaming, "All I want is for my car to keep me cool!" It is my hope that I have given you enough information, to at least hold off on panicking until you can see if the situation truly warrants it.
Until we meet again, try to stay cool... and remember that your vehicle also deserves the Golden Rule.
PPM
P.S.: Yes, the Zach Morris mention was a "Saved by the Bell" reference. Kudos if you caught that!
Subscribe to:
Comments (Atom)