Here is a link to an earlier thread from mp51998 on this subject but the questions were not fully resolved. I too am trying to find the "Low Side" connection point which according to my gauge connectors is the other way around to that described (see pic)

Also is this the same pipe but with both types of schrader valves on it?

I ask because with Hi+Lo manifold gauges connected the readings look suspiciously the same.

As far as I know the r134a needs to go in on the "Low side" after both sides have been evacuated.

So before I do anything can anyone confirm 100% the correct Low+High side connection points?

Of course I will feed back all the results etc to the forum.

 

You have it correct...... The orifice tube is inside that joint in between and separates the high and low side. The high and low side valves are different sizes too so you cannot connect the gauges up wrong. With the truck off, after several minutes the pressure will equalize and show around the same pressure on both sides.

 

Thanks MixManSC for your very helpful information it very much appreciated and what I hoped was the answer.

I will try and service the A/C later and I'll feed-back the results, however I have the feeling the compressor may need replacing.

Thanks again!

 

If both readings are the same while the AC clutch is engaged then it means your compressor is broken internally. It should take a min or two to get an initial charge in the system to get the AC clutch to engage. If it took an hour most likely you will need to bypass the low pressure cut off switch to engage the AC clutch.

 

Thanks for you comments.

I can see the clutch has engaged but not sure if the compressor is being driven. So it could be a clutch problem or a bad compressor, anyway I've ordered a replacement kit.


Will post results.

 

hey oceanbrave was there ever a follow up on your issue? and yes i know about necrobumping been here long enough gents.

 

Good call bronxteck, this was my very 1st post and you've caught me out on the dreaded broken thread i.e. one started and left unresolved with no follow-up.

Had to look up "necrobumping" as it sounded like something out of the movie "Chronicles Of Riddick" but your enquiry is a legitimate one.

So 7 years later in a Hummer far, far away .....

Both the compressor and clutch turned of to be "shot to bits" as calif phil correctly suggested.

So fitted a new compressor, new orifice tube, new accumulator dryer, and reverse flushed the heater core and cleaned out all the tubes, the amount of debris was frightening.

Unfortunately the new condenser was defective, so ended-up cleaning and re-fitting the old one against all advice and my own better judgement, but I had no choice.

Today the A/C system is down to about 25%, some small leak, probably the old condenser or schrader valves, but R134a has got really expensive over here which changes things.

Due to this increase cost, 2 years ago I took the truck to a shop and got them to re-fill and replenish the lost PAG oil. However they insisted on 80% filling the R134a and point-blank refused to put in the full 1.6 lbs, the results were as expected, the A/C under-performed.

 

does your compressor ever cycle?
i ask because i never witness my compressor cycling. it does put out 60 degree air when the climate control is at 60 without recirc enabled. but it was 68*F yesterday when i tested.
also i have a 2003 which seems to use 1.8 pounds for some reason from what i read? is that correct?
i dont know if walmart delivers to your side of the pond but seems the place to still get it at a reasonable price before the tree huggers make it unobtainable. https://www.walmart.com/ip/SuperTech...2-oz/100977940

 

Thank you bronxteck for the link.

Registered with Walmart but sadly no delivery to UK.

To calculate the cost of import the UK has 7% import duty on Goods+Shipping) then 20% VAT.

So assume 2 cans (2lbs) = $11 + shipping @ say $50 this works out to be 61 x 1.07 x 1.2 = around $78.

Here 2lbs costs around £47 approx. $58

Either way its not as good as $11

I don't recall mine cycling either, I just checked only to find mine has again stopped working (wish I hadn't looked)

As for 1.8lbs I wouldn't want to say 100%, I just check the manual for 2003 and found this:-



There should be a sticker under the hood on the RHS I guess whatever that says will be accurate (hopefully)

It's been an expensive week just had to fit a new RH impact sensor $270 for me here and was not easy to find, got the last one from R/A GM 10370148.

Couldn't easily find a Dorman 590-215 which fits 03-07, again I have to watch the import duties which are sometimes hidden until the good arrive in the UK then it's too late to dispute.

Have to say R/A are usually the cheapest and fastest and no hidden charges, the sensor only took 4 days.

BTW the impact sensors are "smart" devices, not just a simple switch as I first thought:-

 

those R134A cans are only 12oz so not quite a pound 16oz would make the pound.

did the sensor fail the usual way? water intrusion causing it to swell and crack? the suburban's / tahoe's , truck's and Cadillac's have similar sensors i wonder if those can be interchanged / used.

i do see rock auto sells A/C kits that consist of compressor, condenser, receiver drier and seals is that what you used for replacement?