Air lift 550000 coolant refilling tool

[Newfangle9]

I was wondering if anyone here has used one of the versions of this tool to replace their coolant. It looks like it works pretty well. I just have a few questions about using one of these on my 95 530i. When you draw 25 lbs of vacuum into the system the hoses are squeezed flat almost, and I wonder if that much vacuum might stress old plastic parts like the radiator ports etc. Also, nobody in the videos I watched mentioned anything about the thermostat. I assume that enough vacuum must pull the thermostat open. looks like I need to remove my radiator to find a transmission oil cooler leak. I replaced the two o rings on the lines to it, but something is still leaking and I can't see it. Any advice, or tips would be appreciated.
forgot a link to tool https://www.youtube.com/watch?v=FQnfUe6P5VI

[bmwdirtracer]

I use a vacuum-fill tool on every single cooling system job I do. The vacuum is not a significant stress; if something breaks under this vacuum (never seen that), it damned sure would explode when subjected to cooling system pressure. Never mind the thermostat; the vacuum system removes all the air from the system, from both directions.

Now, as for your transmission fluid migration: You need to explain this. Are you saying that transmission oil is migrating into the cooling system? Or, vice versa? Why do you believe this to be true?

[Newfangle9]

Thanks for the reply. No, no transmission fluid in coolant or anything bad like that. I just have a leak somewhere around the transmission oil cooler. I already replaced the two o rings for the lines to cooler,but that didn't stop the leak. I don't see anyway to really check around the cooler without removing the radiator. I have read here I think that it is pretty rare for the cooler to develop leaks, but the only way to know is to remove the radiator. I can pull the radiator back enough to see the cooler, but there's only about an inch or two clearance, and it looks fairly gooey and oily down there.Also, I thought that the tool I linked to was pretty neat, but I was talking to my parts guy who has been selling bmw parts and working on them for 40 years or so, and he mentioned to me that my 530i cooling system is self bleeding even though my bently manual says that there is a bleed screw ( i don't see one anywhere). Sounds like replacing my coolant will be pretty straight forward. That's why I asked about the tool.

[m3bs]

I've used a similar tool from ECS on S54 and S50 engines. Works well. No issues with air pockets, etc.

[bmwdirtracer]

I bought my first such tool, when I was at the dealership, some ~16 years ago, because it was very embarrassing when I'd finished some cooling system work, bled through the normal procedures, test drove the car, and sent it home.....only to have it arrive back, on a flatbed, thirty minutes later, steaming. That problem went away immediately when I got the vacuum-fill tool, AND I discovered an equally important benefit: You'll identify leaks in the system, BEFORE adding coolant! (If there's a leak, it won't pull and hold the vacuum).

After going to work at an independednt Euro shop, I bought the whole set of adapter caps, for every make and model; expensive, but over time, worth every cent.

[Newfangle9]

Thanks again for the replies. At best I'm just an amateur shade tree mechanic so I hadn't heard about this tool until a couple days ago. Sounds like a good purchase for me. I always enjoy finding easier ways to do things.

[thejlevie]

I agree with Chris. A vacuum bleeder is the best way to ensure that there is no air in the cooling system.