I have a few questions that I would like to have answered.

1. Does taking the belt off of the AC compressor make much of a difference in mileage when you arent using the AC? I had a friend tell me he made 3mpg more without the belt on. I did this to mine and I just cant see the difference.

2. How much does the AC inhibit on your mileage on a hot day? It is 97 here today but I dont have any freon in my AC unit and I would like to have it refilled. Is it expensive to have the system recharged?

3. Is there a way to tell if the AC system is leakproof?

Thanks for any help.

Fordman

 

here are some answers in the order you asked them
1. turning off the compressor via the dash switch will do the same as taking off the belt since with the compressor off it just sits there and the clutch allows it to free spin.
2. since on a hot day you will have it running all the time and it will probably hurt your mpg a little but not to the point that you'll notice a difference. Theres a price to pay for every thing.
jc whitneys have a r-13a upgrade kit for about 50.00 ( <a href="http://www.jcwhitney.com">http://www.jcwhitney.com</a> )
3. the JC whitney upgrade kit includes a can of stuff which can find a leak. dont know how it works but the kit includes it.
hope this answered most of your questions
BigRebel (aka.Mike)
1979 F-100 w/302 & C-4
Icq#1753451
<a href="http://www.geocities.com/Baja/Canyon/2016">http://www.geocities.com/Baja/Canyon/2016</a>

 

I've pondered that thought and someone once said it is cheaper and conveniant to fix your system than roll your window down and listen to a conversation. Makes sense if the windows rolled up then you use less gas, than when the windows are rolled down.
On system leaks that is up to service tech. pull a vacumm then see if the vac is steady at 29.8microns not inches microns are a more sensitive way of detecting slow leakage.

 

Hey FM,
1-NO Sir
2- I think that the heat has already gotten to you. Take your ride to an A/C repair shop, not some shade tree mechanic (freons to damn expensive now)You may have to spend a couple to three hundred dollars, but riding in a hot truck just sucks.
3- If you go to an experenced shop they will fix all of the leaks. You have to have a license to buy freon now, thanks to all the tree huggers.

Get Kool man,

John

 

Cost me $110 to convert from R12 to R134. I used a good qualified mechanic who sets the timing on the compressor to compensate for the difference in the compression of the gases. Works great, I've done 3 vehicles and all cool great.

Steve

 

Your friend is mistaken. It never did cost 3Mpg to use the AC all the time. The bigger the engine the less fuel it cost's. Get it fixed and quit screwing up our atmosphere.

 

Fordman:

Here's some answers to your questions:

1. NO. The clutch on the A/C pully kicks out when you're not using the A/C and the pully freewheels. This takes only a small fraction of a horsepower so it's not worth your time taking it on and off. Also, your A/C fan belt may also ride over the water pump pully, in which case you want it there to equalize the load on the water pump bearings. Your friend may have had a bad clutch.

One problem with A/C systems is that they are not used in the winter and the seals can get hard and shrink, causing leaks. To fix this problem, newer cars (mid '80s and newer) cycle the A/C pump whenever the defroster is turned on. This both pressurizes the system and keeps the freon moving so the seals stay fresher longer. It's a good idea on older cars and trucks to use the A/C for a few minutes at least once or twice a month.

2. Long ago my wife inherited a '71 Dodge Dart Demon with a slant 6. She used it during her college years then gave it to her younger brother. She found that on hot days it cost her 1-2 MPG to drive on the freeway with the windows and vents open, whereas the MPG drop was not discernable when she used the A/C. Kinda blew me away when she showed me the numbers.

Now that your system is fully discharged, take it to a licensed A/C shop and have it converted to 134A. Freon 12 now costs over $30 per pound and is quickly headed to $40 . The sooner you convert the sooner you start to save money. I just bought a '71 F-350 Ranger with a broken engine and this is what I will do next month after I get it running.

3. The vacuum test tells you if you have a leak, not where it is. The JC Whitney test kit probably has a dye in it that glows under a black light. It's better to go to a qualified A/C shop because they have a sniffer that can detect leaking freon and tells them exactly where the leak is, if one exists. They then change that hose or fitting and you have a sealed system again.

Good Luck.

Bruce