craig.wilson1

So I'm planning to take the front end off of my 2012 Q5 2.0 TFSI in order to replace the timing chain and tensioner. This will require draining of the coolant in order to remove the hoses connected to the radiator. When I get everything back together, I'll need to refill the system with coolant. I've downloaded all the Audi ErWin manuals I'll need, but the procedure for draining and refilling the coolant is missing for some reason - the procedure just tells you to reference the section that you're currently looking at??? I've seen a YouTube video where it's highly recommended to use a vacuum fill system to ensure no air pockets in the system. The kits themselves are relatively cheap, but they require an air compressor, which I don't have. Does anyone have any recommendations on this procedure, either with the vacuum kits or, preferably, without?

SMac770

Some idiot at VAG decided to start splitting the engine and transmission manuals into two documents. And information is randomly separated between the two, the "normal" doc and the "servicing" doc. Absolutely irritating. But they hadn't done that to the EA888 Gen2 engine document that I had seen. But the copy I have is from Sep 2016. What is the edition date on the copy you are using? In mine, drain/fill is discussed in 1.3 under 19-cooling.

Searching around the B8 A4 and B8 A5 forums here and at audizine. How to try and fill the system without the proper procedure has come up before, but I don't keep an inventory of threads to reference. A pneumatic vacuum extractor does require an air compressor, but there are also electric and manual vacuum extractors. But you only need a 101-145psi air compressor, and the manual doesn't spec the CFM requirement. I'd likely figure out some way to connect my hand pump oil extractor tool, but you can get an air compressor for not much and might be useful for other things. https://www.homedepot.com/p/RIDGID-6...50HB/303379052

craig.wilson1

Thanks for the quick response. I looked around a few of the other ErWin manuals I had downloaded and found one that had the coolant drain/re-fill procedure. I checked a few local auto parts stores to see if they had vac-fill kits for sale or rental; they don't, so I'll likely have to order one on Amazon. I can rent a small portable compressor from a local shop for $20 so I'll probably go that route.

craig.wilson1

So I bought a Jifetor Vacuum Fill kit from Amazon and rented the smallest compressor available thinking that it would be more than adequate for the job of filling the coolant. It turned out that the ejector on the Jifetor kit required a high volume of compressed air to generate vacuum and the air compressor couldn't keep up. The Jifetor kit instructions called for generating about 25 inHG before filling with coolant. The small compressor could only generate 12 inHG before losing pressure, so I had to do things in multiple steps. In the end, it worked find, but I would recommend that others use an air compressor that has a large enough air tank to sustain good airflow to generate "full" vacuum.