I pulled the long low pressure side hose from compressor to expansion valve off a junker 300D for my 300D. Don't have air compressor. What can I use to flush hose?? Is isopropyl alcohol ok?

Any auto parts store sells AC line flush solvent - just ask for it....

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

It is very common for folks to use Mineral Spirits or Brake Cleaner for flushing a/c components. Mineral Spirits leaves behind some residue, but it's cheap, so lots of people use it for a main flush then flush that with a/c flush or Brake Clean. Either one of these three must be THOROUGHLY blown out with compressed air.

In the old days after a system being opened, we would put things together and with a few key points open, have gauges and refrigerant set up and simply sweep the system by blowing an ounce or less of refrigerant through the line then immediately hook it up. This would blow out most moisture and other elements from the air, allowing for a quicker and more thorough evacuation. This practice is illegal today, however.

hey pete,
best is to go to a welding supply house, or the like and use dry nitrogen along with the a/c flush. (I wish you were closer to me...) I've seen the empty bottles with regulators going on ebay for as little as 15.00 and it only takes 12.00 to fill one. new the bottles cost over 200.00 and the regulator is another 50.00... not very cheap! but it's the best way to flush lines with the chemical solvent.
do you have a vacuum pump? an old refrigerator compressor will work for one, but you have to get fittings welded on...
gimme a call and I'll help ya get it all cleaned up.
(this is turning out to be a fun project for ya ain't it?

I don't have nitrogen but have argon and oxygen. Will either one of those work and if not, why not?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

100% Argon will work just fine. It is inert like Nitrogen. It's just more expensive. No pure O2 though, there is oil in the system.

I wouldn't use Argon/CO2, although that might also be fine.

DO NOT USE OXYGEN!!!!! your car will EXPLODE!!!!!
seriously, very very very very very explosive! do not use oxygen!!!

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

a good cheap purge gas is helium! and it's relatively available at most grocery stores, and wall mart!!! like 20.00 for a 15 lb size of helium! and they usually have a rubber connector you can push into the hoses to flush them! (I already discussed this with steve on the phone, I'm posting it here for everybody else!)
I can just imagine the sounds of the mechanics working on this... mickey mouse and minnie!!!

How about for leak tests? I would think that helium would leak out rather quickly compared to nitrogen, because it is a very small molecule.

But for purging, I hadn't heard of that idea, and it sounds great. Same for breaking a vacuum without introducing air.

Hey John.

Thanks for the tip earlier today on the phone. Going to walmart now to find the helium. I am using the brake cleaner first then flush with the helium

only one molecule smaller, and I don't recommend using that one...

Just finished flushing the ac hoses with the brake cleaner and the helium. Looks like it worked well...

Now if I can only unscrew the bolt in the middle next to the valve to make it two pieces. The thing does not want to come off

cool. how much was the helium? tell the truth, you took a hit didn't you?

I paid $20 for the Helium, but it was only a couple of pounds. Came in balloon kit with 30 balloons for kids parties.