If I don't have to start over and I get my new hose quickly enough and still run into the same issue, do you think that I could pay a shop to do a nitrogen test for me and tell me where the leak is?

 

I am not sure what has happened. So most people would put the yellow manifold gauge hose on the vacuum pump and then the blue and red manifold hoses on the AC system ports. If the vacuum pump has a blanking valve to take it out of the circuit then good, otherwise you need to add a shutoff valve where the yellow hose connects to the pump. Then before you involve the entire system you do not yet open the ports at the trucks ac system but you do open the blanking valve and start the vacuum pump and open both the red and blue valve at the manifold gauge set. Then you see if the pump can pull everything from pump to ports down to a 28-30 in hg reading and if so, close the valve at the pump and turn the pump off. See if the vacuum holds for 20 min. If so then start the system evacuation by starting the pump and opening the system ports. If not then see if the pump itself can pull down with the shortest hose and single gauge. Then determine why the pump to AC port will not develop or hold a proper vacuum. Everything here should be hand tightened except maybe the gauge dial to manifold block but I have never had a leak there in about a dozen manifold sets.


George

 

Another thought:

You have done most of the work and saved the labor and markup on the parts. You might try to find a mechanic that has the equipment and wants to make some money on the side to pressure test, pull the vacuum and charge. If not then scout prices from local shops. Depends on how much more of this part you want to learn. I'll keep helping you if you want to see this through.


George

 

Sorry - I see now how that was unclear. I wasn't having trouble with how to check the pressure and pull a vac.

I cracked the aluminum block at the end of the ac hose assembly leading up to the compressor ports. Yeah. That just happened. I don't know if Blazer Forum has a stupidity contest, but I'm pretty sure I just swooped into a strong first.

It would appear that my torque wrench doesn't work because it did not click when I was tightening down the ac hose to the compressor. I'm also now wondering if I overtightened the bolts holding down the compressor to the engine, which I have read can also be an issue.

 

Not stupid, your asking questions and learning. My first couple of AC systems had a few, you gotta be sh&*&^ng me I can't believe I just did that moments but I stayed with it and got the hang of it. Sorry, your not anywhere near first place. LOL.


George

 

Thank you for the reassurance and support, George. Good to know that I still have some stiff competition out there when it comes to the Idiot Olympics.

Seems like we had the same idea about the mechanic for the vac test.

Also, just looked up the dry nitrogen test. I'm guessing you don't want to use compressed air because of moisture-related reasons? Otherwise, I don't see why soapy water and compressed air wouldn't do the same job - or even no soapy water and just putting my hand near the connections since HOPEFULLY there should not be any holes/leaks in the actual components. Would that last part work fine in the dry nitrogen case?

Regarding moisture and the oil, since I have an open system now, is plugging everything good enough until tomorrow? Or could I ultimately boil off the moisture if I vacced long enough? on a reasonable time scale that is, not when time approaches infinite lol

 

I actually prefer soapy water and feeling around for a light oil film for leaks. I have sophisticated detectors but don't pull them out unless plan A fails me. Compressed air can contain improper oil and moisture. If your considering going that route you will need a serious moisture and oil filter/trap. I don't recommend it. Whatever you do don't go over 150 psi.

I really don't know where we are regarding your open system. I have no experience with splitting hairs on days open, exposed oil, etc. Any problems that this might cause would have a delayed reaction. Once you get the kinks worked out of your process you might consider replacing the oil and the accumulator. I can't say with certainty that this is necessary. Only you can decide if $30 bucks for an accumulator and oil is worth it vs the risk of a failure from moisture and acid. I hate wasting money and reuse everything but sometimes I just want it done right, especially if I would have to redo a big job or might kill a compressor.


George

 

This is my dry nitrogen rig, I don't know if it can be rented/borrowed.

George

 

When you're right, you're right, George.

Now that finishing tonight is no longer an option, I guess I don't have to worry about being on a deadline and can take my time.

I guess the new (general) plan is: get a new accum, hose assembly, bottle of pag oil, and torque wrench, apparently; unmount and drain the compressor; get 8 oz of oil and leak dye split between new accum and compressor; replace accum, hose assembly, and compressor; double-check all connections; pull a vac and see if it holds, otherwise find a shop.

 

Trying to figure out what could have gone wrong and, after reviewing Christine's thread, think that it was because I should have bent the rigid part of the hose assembly to clear the compressor mounting bolt based on the fact that I did have trouble getting it on there - even though I thought I had managed it fine.

Since I might be ordering parts, it'll take a couple days for them to arrive, but I will need to drive the car. Will it be alright to be driving around with a new and disconnected compressor, provided I plug everything up? I am also going to remove the hose (don't want anything dangling) and plug the accum and cond.