A/C Question

[BIGSHOMIKE]

I did a coil and clutch on my compressor and when I was done it would kick off too fast so a technician told me to adjust the low pressure switch, this worked but then I turned it a little more so it blows colder. Will this damage anything? He said leave the high pressure switch alone because it protects the compressor. The one I adjusted is up by the base of the windshield.

Thanks

 

[Slo-Sho]

When the compressor cycles rapidly that means the system is low on refrigerant.

 

[rangerj]

BIGSHOMIKE,

Yes, the high pressure switch protects the compressor, but so does the low pressure switch.

The low pressure switch is set for 20 psi. If the pressure drops below that the switch is "turned off". The reason presure drops is a leak in the system. The oil circulates with the refrigerant, and if one leaks out so does the other.

The low pressure switch prevents the compresor from being run with to little oil. Further, if there is a leak, there is the possibility of moisture getting into the system. Moisture in the A/C compressor is not a good thing. Would you put water in your crankcase?

Check your A/C connections for a fine black oily residue. This is A/C oil that has attracted dirt.
Fix the leak, then vacuum the system for a minimum of 45 minutes to remove all traces of moisture. Then recharge the system with refrigerant and a couple ounces of oil.

Check the gap between the clutch face and the pulley. It should be about .035 for most compressors. Check the clearance for your model year. A gap that is to large can also cause the clutch to "cycle' frequently.
Hope this helps, rangerj

 

[Vito117]

BigSHO;

What was your procudure to change the AC clutch out? I'm doing the same thing this weekend.

93ATX 136k

 

[BIGSHOMIKE]

Thanks for the info. I actually had it vacumed twice at my friends shop, then recharged and the pressure checked, it held the vacum well so no leaks I'm guessing. It wouldn't turn on at all till we adjusted the switch, now it works really well even stopped in traffic. That make any sense?
I don't know much about A/c.

When I changed the coil I also did a clutch and a pulley. I took out the battery, the battery tray, removed the drive belt, and had to take off a pulley( don't remember which one) to get to the alternator bolts, the took off the alternator so I could take out the compressor bolts. I didn't open the system I just pulled the bolts so I could move the compressor to get to the snap rings esiar. Take the bolt out of the middle of the cluth and take it off, I used 2 flat head screw drivers and gently wiggled it off. Then there is a snap ring holding the pully on, and after that comes off there is another holding the coil on. There was also a wire connected to the coil you have to take off, The biggest pain for me was the snap rings because they are really thick, so when you go to spread them they don't spred round. Also when you take the clutch off watch out for the little washers, they are to set the gap on the new one, mine came with new ones but I saved the old ones too.

 

[rangerj]

Bigshomike,
Sounds like you did it all right. Nice job.

In re. the changing of the clutch, clutch pulley, and coil for the A/C;

1. After removing the nut, or bolt, holding on the clutch face, it can be pryed off with a pair of screwdrivers.

However, if you are going to reuse the clutch face and pulley, the surfaces can be damaged by the screwdrivers.

Use a couple of wood shims and drive them between the two surfaces. The wood will not damage the surface. There is a "special tool" for pulling the clutch face off, but it is not necessary.

2. Next, remove the snap ring that holds on the pulley. It is beveled on one side. The beveled side should face you, that is the outside, when it is installed. The early years, up through 92, have a replacement bearing for the pulley.

The spring that holds the bearing in should be removed gently so as not to destroy it. It fits in a groove behind the bearing. Then press the bearing out, and the new one in.

3. Disconect the electrical connection to the A/C coil and remove the snap ring that holds the coil in place. Again, the snap ring is beveled and the bevel should face you when it is installed.

Take a good look in the compressor where the shaft comes out for any sign of a leaking shaft seal. You may see the black oily greasy stuff, or clear oil.

WARNING to ANYONE who reads this! DO NOT TOUCH A NEW A/C SHAFT SEAL WITH YOUR BARE HANDS. Wear rubber or latex gloves. You can get the gloves in any hardware store or paint department of stores like Sears or Home Depot. The oil and acid from your hands will ruin the seal and shorten its life.

Whichever one you find it indicates a leaking seal. It does take special tools to remove and replace the compressor shaft seal. However, a small leak may let you get through a whole season with a recharge.

This should be an easy weekend project! rangerj

 

[BIGSHOMIKE]

Thanks but I take no credit, I bought the clutch, coil and pully as a kit, came with new snap rings and shims etc, and.......INSTRUCTIONS!!

Now theres a novel idea, heh?

I also called the mechanic I go through for some tips.

 

[rangerj]

Bigshomike,

Just curious, did you read the instructions before or after you started working on it? It is a rhetorical question, asked with tongue planted firmly in cheek.

Now if I could learn to read the metric side of my calipers I'd be all set. I'm going to look for the instructions to the calipers. I guess after owning them for 15 years it's time to read the instructions!

If this does not make sense to you, read some other post of mine and come back to it.

Anyways, no matter how you look at it, you got it done and you CAN take the credit. rangerj