4.2l coolant leak at union
02-17-2018, 09:20 AM
#1
4.2l coolant leak at union
My 2012 A8L 4.2l started leaking coolant from the rear of the engine right before Christmas. I finally had time to take some things apart and found the leak is coming from the coolant union on the rear of the engine- driver's side. Part is 079-121-127-F. Has anyone else had this issue? Can it be resolved without engine removal?
02-18-2018, 07:41 AM
#2
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I just had this issue fixed a month ago by the Audi dealer. It took a few days and $1700 later but the leak is gone. It was a very slow leak but I was having to add coolant every 3 weeks or so just depending on how much I drove. I have 2011 Audi A8L
02-19-2018, 05:30 PM
#3
Thank you for the info! I bought the erWin 1-day subscription and downloaded the factory manual and may still give the repair a go on my own. But.... it makes me feel much better that the dealer "only" wants $1700. I was afraid of something in the area of $3-4K.
03-25-2018, 07:53 AM
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Coolant leak 2011 Audi A8l
i has the same issue last year before thanksgiving. Mine was the connecting pipe that connects the left and right adapters. Yea the dealer wanted like $1500 and a few days. My coolant was draining out over night. I changed it with my coworker in three hours. The “plastic” part was like $90. It wasn’t easy but we did it. Make sure they give u all the right orings cause I had to reuse one of them and maybe that’s why it’s leaking alittle now. Haven’t looked at it since it’s been cold. These dealers are rapists
04-19-2018, 09:49 AM
#5
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i has the same issue last year before thanksgiving. Mine was the connecting pipe that connects the left and right adapters. Yea the dealer wanted like $1500 and a few days. My coolant was draining out over night. I changed it with my coworker in three hours. The “plastic” part was like $90. It wasn’t easy but we did it. Make sure they give u all the right orings cause I had to reuse one of them and maybe that’s why it’s leaking alittle now. Haven’t looked at it since it’s been cold. These dealers are rapists
04-20-2018, 11:41 AM
#7
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04-22-2018, 06:17 AM
#8
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Coolant leak
God be with u! The way we did it was we removed the left adapter to pull out the connector pipe. There’s a aluminum pipe running along the left street de of the engine that’s connected to that same adapter. We just unscrewed that pipe from the engine so u get like a inch of extra space. I want to say the bottom bolt on the left adapter was the hardest to put back in. I was using the tips of my fingers to thread it back in. I also removed the plastic tubung that connects the Two air filters. It gives u more room on the top!
05-03-2018, 09:12 AM
#9
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Job done. Not for the weekend mechanic or one with large forearms and hands. Not much clearance. Parts were about $60 including extra o rings, clamps and the two specific collars that hold the pipe in place. Took me several hours to get the old parts apart and out.
Picture is of old pipe with a broken t-union going down to cool the transmission. Also a side union is broken off on purpose. I did access everything from the top. Part number for union 079-121-071-BS. Next time I’ll pay the mechanic to do the job!