To Flush or Not to Flush? AC that is (1 Viewer)

[Bisho]

I have a leak in my A/C system. I'm still sorting through it, but I do see some dye behind the compressor pulley, and the condenser appears to glow as well. Given I have new dark/oily stains on the front of the motor being blown back by the fan, it seems the condenser is likely the culprit. I have no record of the a/c system having components replaced up until now (260k miles). The compressor has not mechanically failed.

So...I see a Rock Auto kit (UAC, not Denso...let the hate begin) that includes a new compressor, condensor, and expansion valves. Given there has not been mechanical failure, is it necessary to flush the system?

 

[vipergrhd]

If you are just chasing a leak I really don't think it's needed to be flushed and condenser do get a beating and there is good chance it will have a leak.
If you end up replacing the compressor and condenser make sure you drain the compressor oil in a clean container and only add about 2 oz. of oil and another .5 oz in the condenser unless you have a bad expansion valve I would leave it alone. Just to add in the event you have compressor failure it is almost impossible to flush the system specially the condenser it is best to just replace everything minus the hard lines.

 

[JunkCrzr89]

I agree with @vipergrhd

I wouldn’t flush it unless all of the refrigerant drains out through the leaks and you have an open system for multiple months that gets contaminated. Otherwise, just vac all of the moisture out after you replace components and before you pump in new refrigerant.

 

[Bisho]

Thanks, guys. I was hoping that would be the consensus.

 

[kidphc]

I only flush when the compressor bearings take a s***. For the most part, on the newer cars with high efficiency systems people cry, because it is recommend to replace almost every components of the system. Especially, if they used stop leak. The condenser/evaporator internal openings are tiny. Some cores you can't even get a sewing needle into the channels.

For our systems pretty much replace what you can or need to you know drier, receiver, condenser and compressors. Only flush when necessary, bearing failure, stop leak contamination etc.

Our condensers take a beating, mine on a 2000 with 277k had an entire line of fins separated from the core. It looked like a nhl hockey player's mouth from old.

Universal Air isn't terrible, better then the Duralast, etc garbage. I use the Universal Air and Global Air at the shop all the time. I do prefer 4 Seasons or Denso if I can get my hands on them.

 

[Lonegrasshopper]

If you are just chasing a leak I really don't think it's needed to be flushed and condenser do get a beating and there is good chance it will have a leak.
If you end up replacing the compressor and condenser make sure you drain the compressor oil in a clean container and only add about 2 oz. of oil and another .5 oz in the condenser unless you have a bad expansion valve I would leave it alone. Just to add in the event you have compressor failure it is almost impossible to flush the system specially the condenser it is best to just replace everything minus the hard lines.

We still replacing the dryer when replacing the compressor for insurance? It was a practice done in days past.

 

[JunkCrzr89]

We still replacing the dryer when replacing the compressor for insurance? It was a practice done in days past.

I would. They’re cheap.

 

[vipergrhd]

@Lonegrasshopper Yes most definitely always replace R/D when replacing any major components. On some newer vehicles it is mounted along with the condenser and you just replace the bag inside.

 

[Bisho]

I ordered the UAC kit to install this weekend. Is all R-134a created equal? Any reason to pay more than $5/can at Walmart?

 

[jerryb]

yes- domestically at least, I would guess.
no
Just no dye, no oil. gas only.
I would be a lot of money the price of 12 ounces will be 4x todays cost in 5 more years.
Most new cars are 1234 type.
I've watched r12, and 134 prices at walmart for 25 years with many cars. I hate the resealable cans. But I buy them whenever I'm at walmart, as much as I despise that place.
I remember having 30 cans of the straight puncture type, they were less than 2$
sorry for the rant.