Accidentally opened AC line hex bolt and now it leaks refrigant

M'EM · 09-09-2020, 12:20 AM

Hey Guys,

I was doing a spark plug change and the Driver side innermost one was extremely tight to get into so dumb me thought I can wiggle the AC line a bit to make it a little easier. I ended up loosening the hex bolt that is right below the low pressure port on the AC line and as soon as I loosened it there was a huge hissing noise and complete leak of all the refrigant from the line. I tightened it immediately but the leak wouldn’t stop. I bought a AC recharge kit from the store and tried recharging it today but it leaked out immediately as I was filling it in. What do I do? Is it a bolt that never should be loosened or what is the deal

...anybody know? I am in Florida and frying in the car on a daily basis

Titaniu//M · 09-09-2020, 01:20 AM

The o-ring on the end of the refrigerant line is probably displaced. It is generally advisable to get new o-rings every time an AC line is removed and reinstalled. Buy a new o-ring, fit it to the line, and recharge the system again.

amrazM · 09-09-2020, 05:12 AM

the gas in the ac system is under pressure and pressurized air will always escape out of the path with the least resistance, bmw calls for the ac system o rings to be replaced when the line is moved or displaced.

i believe this is the seal you need 64538375742
but posting a picture of exactly which line would be helpful.

nrubenstein · 09-09-2020, 09:17 AM

You need to replace the o-ring if it's leaking.

AC systems need to be VACUUMED prior to filling. Modern AC like in the E90 requires an extremely precise fill in order to work correctly as there's remarkably little refrigerant in there. Too little refrigerant, things don't work correctly. Too much and you can rupture components.

You need to either pay someone to fill the system, or acquire a vacuum pump, scale, and gauges.

And you want to fix the system as quickly as possible. The AC dryer on the E9x is integrated into the condenser.

Binary420 · 10-06-2021, 10:13 PM

I know this is old but can anyone tell me what that hose is called so I can locate a replacement bolt for it? I dropped mine and it disappeared. Literally. Gone.

It's the ac pressure line right next to the passenger valve cover
It's 1 torx bolt holding the hose in the metal base (which is about even with the oil filter cap but much lower down )

09-09-2020, 12:20 AM	#1
M'EM Lieutenant 180 Rep 478 Posts Drives: JZB M3 Join Date: Sep 2015 Location: Tampa FL iTrader: (1)	Accidentally opened AC line hex bolt and now it leaks refrigant Hey Guys, I was doing a spark plug change and the Driver side innermost one was extremely tight to get into so dumb me thought I can wiggle the AC line a bit to make it a little easier. I ended up loosening the hex bolt that is right below the low pressure port on the AC line and as soon as I loosened it there was a huge hissing noise and complete leak of all the refrigant from the line. I tightened it immediately but the leak wouldn’t stop. I bought a AC recharge kit from the store and tried recharging it today but it leaked out immediately as I was filling it in. What do I do? Is it a bolt that never should be loosened or what is the deal ...anybody know? I am in Florida and frying in the car on a daily basis __________________ 12' E93 M3, JEREZ BLACK, M-DCT, BORLA ATAK, 19" BMW GTS WHEELS, LUX H8 180 ANGEL EYES, M STRIPED BLACK KIDNEY GRILLS, SMOKED BLACK SIDE GILLS, IND PAINTED BLACK REFLECTORS.
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09-09-2020, 01:20 AM	#2
Titaniu//M First Lieutenant 48 Rep 325 Posts Drives: M3 Join Date: Oct 2019 Location: Cincinnati, OH iTrader: (1)	The o-ring on the end of the refrigerant line is probably displaced. It is generally advisable to get new o-rings every time an AC line is removed and reinstalled. Buy a new o-ring, fit it to the line, and recharge the system again. __________________ 2006 BMW E46 M3 Coupe - 6MT - Titanium/Imola 1999 BMW E36 M3 Coupe - 5MT - Estoril/Dove 2000 Honda Civic Si 2011 Toyota Tacoma PreRunner T/X TRD
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09-09-2020, 05:12 AM	#3
amrazM mTekMods 2143 Rep 2,902 Posts Drives: like a granny. Join Date: Jan 2010 Location: Manhatan iTrader: (1)	the gas in the ac system is under pressure and pressurized air will always escape out of the path with the least resistance, bmw calls for the ac system o rings to be replaced when the line is moved or displaced. i believe this is the seal you need 64538375742 but posting a picture of exactly which line would be helpful. __________________ 2011 Frozen Black/Fox Red E90 M3 650+WHP G-Power Supercharged First DCT to Manual Conversion Worldwide KW CS, BBS RI-A, BW Headers, Snow 2.5
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09-09-2020, 09:17 AM	#4
nrubenstein Captain 567 Rep 801 Posts Drives: E30 M3/E36 M3/E46 M3/E90 M3 Join Date: Dec 2016 Location: Washington, DC iTrader: (2)	You need to replace the o-ring if it's leaking. AC systems need to be VACUUMED prior to filling. Modern AC like in the E90 requires an extremely precise fill in order to work correctly as there's remarkably little refrigerant in there. Too little refrigerant, things don't work correctly. Too much and you can rupture components. You need to either pay someone to fill the system, or acquire a vacuum pump, scale, and gauges. And you want to fix the system as quickly as possible. The AC dryer on the E9x is integrated into the condenser. __________________ 2011.75 E90 M3 \| 2006 GMC Sierra LBZ \| 2004 X5 3.0i 6MT \| 1995 M3 S50B32 \| 1990 325is \| 1989 M3 S54B32 Hers: 1996 911 Turbo \| 1989 325iX
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10-06-2021, 10:13 PM	#5
Binary420 Enlisted Member 9 Rep 40 Posts Drives: 2008 E92 M3 DCT Join Date: Jun 2021 Location: San Diego, CA iTrader: (0) Garage List 2008 BMW M3 [9.33]	I know this is old but can anyone tell me what that hose is called so I can locate a replacement bolt for it? I dropped mine and it disappeared. Literally. Gone. It's the ac pressure line right next to the passenger valve cover It's 1 torx bolt holding the hose in the metal base (which is about even with the oil filter cap but much lower down )
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