What are the methods used to replace coolant on a vehicle without a drain? I am due to change the coolant on a vehicle with a very tight engine bay and no drain plug in the radiator. The hose clamps are almost impossible to reach because it's a turbo engine and the front mounted intercooler pipes are in the way. On vehicles with a drain valve in the radiator, it's a very controlled process, coolant is emptied into a bucket or pan with minimal effort and mess, what methods can be used in systems without a drain? There is no radiator cap either, just a Schrader valve for bleeding air and a coolant reservoir away from the radiator.

  • If you gave us the year/make/model/engine of the vehicle you're working on, we might be able to give you specific instructions on how to do this for your car. – Pᴀᴜʟsᴛᴇʀ2 Jan 29 '17 at 22:04
  • It's a new Renault Clio with the 0.9L turbo 3 cylinder. You won't find much online as it's a fairly new engine. In fact the only service guides on a few forums are written by myself, no one seems to be interested in these enough to do any work themselves. – DizzyFool Jan 29 '17 at 22:13
  • Again, what's the year? – Pᴀᴜʟsᴛᴇʀ2 Jan 29 '17 at 22:15
  • 2012 or 2013, but I was interested in a more generic answer. If you find something about this specific vehicle that I've missed please share it but I have done a fair amount of googling. – DizzyFool Jan 31 '17 at 9:30
  • Just because there's no drain plug in the radiator doesn't mean there's no drain plug somewhere else. – DavidSupportsMonica Mar 21 at 3:09

In general, the easiest way to drain coolant from systems like these is to disconnect the lowest fitting between the coolant hose and the engine block and let the coolant just drain out. Usually, it's near the bottom of the block itself, so it shouldn't be hard to reach from underneath the vehicle.

  • I'm struggling to see how this could be the proper service procedure for this, the lower radiator hose connects to the side of the radiator and immediately does a 90+ degree bend. I noticed that there is some kind of valve (looks like a Schrader valve) at the top of the radiator. Is it possible that some kind of vacuum system is connected to this Schrader valve and the coolant is extracted in this way? Similar to how dealerships use an extraction hose in the dipstick tube for oil changes. – DizzyFool Feb 1 '17 at 9:15

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