gpeade

Yeah I know, wrong time of the year, but figured this was a good time to look into it. My AC will only cool for a short while then it starts blowing hot air. I'm talking 5 maybe 10 minutes. Seems the hotter the weather temp. the quicker it stops cooling. I have had the system charged so I don't think that's the issue. I know nothing about an ac system so I am at a total loss. Wondering if maybe there was some type of switch or regulator that could be easily changed? Any help would be appreciated.


Thanks

Roler

Well, over here it is exactly the right time of year for this

Although you had the system charged (so why did it needed to be charged in the first place, was there a leak?), it still might be you have a (ungoing) leak, loosing the refrigerant again. So, first step would be to have this checked/tested. The symptom of only shortly giving cold air, can be due to this.
If the refrigerant is the correct level and no leaks detected, we'll look further.

Firestorm500

When the temperature is 70* or better, put gauges on it and take a reading.

My first thought was even with adequate freon, it may not be moving through the system properly.

Don't throw parts at it until you have it diagnosed.

gpeade

What you suggest is consistent with my issue. The truck had been sitting idle for about 6 years when I bought it. The compressor wouldn't kick on so I took it to a local shop and they said it was low on coolant. Well it worked for about a month or so then it started cutting out like its doing now. That would be consistent with a leak I guess. That was two years ago and its still working the exact way. I was thinking if it had a leak then by now it would be low enough the compressor wouldn't come on anymore like before. I will just have to wait and see I guess.

Roler

No, have it tested ...then you know and we can look further if you want/need to.

Muaddib420

This happened with my AC. Worked for a few minutes then would stop. Turned out my compressor clutch was worn. I removed the clutch, cleaned both surfaces with a wire brush and removed a shim. Works great now.

Here's a good video

And here's the tool I used to remove the clutch
http://m.ebay.com/itm/111252762324?nav=SEARCH&sbk=1

gpeade

Interesting info on the video. Mine does exactly as he described. Once it quits cooling the vehicle has to cool off before it will start again. Wonder if the real fix was the shim removal or cleaning all the rust off the surface so the magnet could grab it better. Anyway she is due for an inspection this month so while it's there I'll get them to check my pressures. If that checks out I will try the clutch fix and see what happens.

Roler

Let us know how this went...

freegdr

Remove smallest shim if your digging in...

Roler

while we're on this subject....my A/C sometimes makes a very loud 'clunk' when A/C is selected...not always, but mostly when haven't used the A/C for a while....the clunk can be felt all through the vehicle....new compressor less than 2 yrs ago, all bolts snug and no movement, A/C works fine otherwise, belt tightness is fine...

Roler

After some reading , I found this. My clunk appears to be more common than I thought.

As the compressor and its hoses cool down during the night, the r134a inside them tends to condense. In the morning, when you start the engine with the ac on, a shot of the liquid r134a going into the compressor causes a loud clunk.

The clunk really sounds like something is going to brake sooner or later, but apparently that loud clunk is normal as well..

CCKen

Never heard of it.

Roler

Neither did I....but came across this on multiple different sites....and then you know it all true, of course.
Would love to get some data....if I only knew where to get that on this issue lol. Not sure if there are any double blind randomized controlled multi center studies on this subject, so am open for other thoughts on what "the clunk" could be...

CCKen

See if you can get someone to start the Heep with the Mode Selector in an AC setting and while you place your hand on the AC Compressor and see if it is the source of the clunk.

In the mean time, use a pre-start checklist, as follows:

1. AC/Heat Control Panel, Mode Selector - OFF

Roler

LOL

Oh, I'm almost certain its the compressor, didnt need to put my hand on it (G knows what happens)......And yes, I started to do the pre-start checklist things already some time ago, the whole list, from beginning to end (lol).

What I've done recently is starting w/o AC and start driving and then engage AC...it makes the clunk somewhat less jaw-grinding.

Just wondering if taking the clutch of and have a look at the shims would give me some ideas...the AC is working fine, so I guess not...but really dont know what else I could do, AC is not my area of expertise....