truck A/C issue

[thejudges69]

well this is a question for the car guru's on here. My 379 Peterbilt A/C is going to get a retrofit this weekend, a custom a/c pump and setup. The problem is that we can't vac it down. A year ago I had a receiver drier come apart and it plugged all the lines. I pulled it apart blew everything out and recharged it, well. I think the beads from the drier got into the pump and its plugged again. I'm replacing everything this time again, including the pump which is didn't last time but if I can't vac it down what do people do? do you let it fly? I know thats illegal but what other option is there?

 

[Tarheelgarage]

If the system can't pull a deep vacuumn and hold then you have a pretty good size leak somewhere that will need to be located and repaired before charging with gas.

If you just shot some gas, it will soon be gone

Don't rule out shaft seal being source of leak.

 

[thejudges69]

theres no leak, you have to reread my first post, I can't vac it due to it being plugged.

 

[rodknocker]

You'll have to take it back apart, and make sure there is no foreign material in there. Like Tarheel said, an A/C system HAS to be able to pull a vacuum or it isn't sealing. Even if its plugged somewhere in the system it will still still pull a vacuum as long as there are no leaks, your pressures will tell you if you have a blockage somewhere. Make sure your equipment you're using isn't the source of the leak too, been bitten by that before.

 

[Grumpy365]

You'll have to take it back apart, and make sure there is no foreign material in there. Like Tarheel said, an A/C system HAS to be able to pull a vacuum or it isn't sealing. Even if its plugged somewhere in the system it will still still pull a vacuum as long as there are no leaks, your pressures will tell you if you have a blockage somewhere. Make sure your equipment you're using isn't the source of the leak too, been bitten by that before.

I agree. If it was just blockage it would be like putting your finger over the end of a straw, it would still pull a vacuum.

I would blow it out with nitrogen and try to get the **** out of it.

Then I would try to get a vacuum again.

 

[lzenglish]

And I agree with both of them! Also, as was stated previously, the first place to look for a leak is in the rotating shaft seal, as they will "ALL" leak eventually! Good Luck!

Wayne

 

[mccaer01]

I agree with the above, check the machine, connection valves, it has to pull some sort of a vaccum if there is a blockage, if no vaccum then theres a leak. Also dont forget to check your condensor for damage, happens way to much on Freightliner Columbias and Century classes.