Perhaps he meant a flush of the fluid. Never heard of a drain.. be a devil to get rid of all the air in the lines afterwards.

 

I don't do brake fluid flushes based on mileage alone. I will bleed when doing pad changes with a little extra to get rid of most of the old fluid. IMO unnecessary at 35k

 

Hi. In my opinion it is not nessasary to flush your brake lines. But, each time I replace my brake pads I do a quick vacuum purge from the brake caliper just about 2 ounces of brake fluid just enough to put fresh fluid back into the brake calipers.

 

Brake fluid absorbs moisture and it is very easy to test. Amazon has a brake fluid tester for $5-$10 to test the moisture level in the fluid.

 

Well it would be easy to test if Hyundai and Kia didn't have a stupid screen in the reservoir.

 

Most have a screen. Keeps crap out

 

The manual says to replace the Dot 4 fluid every 48,000 miles. Dot 4 absorbs water faster than Dot 3 so you need to change it sooner. Dot 4 has a higher boiling point but as it absorbs the water faster it gets worse than Dot 3. Honestly changing it depends on the water %. New fluid is clear as water and old fluid gets dark from reactions with the water. If the fluid gets higher than 2% water its time to change. Humid climates will need changing more often than dry climates. Cheap brake fluid testers work well. Now my opinion "The shop is trying to make money for them. 35,000 miles is ridiculous. If the shop was honest they would test the fluid and show you the results, but they didn't because the fluid is still good. They might be correct at 70,000."

 

Yes, it was flush the fluid at 35k. Thanks everyone. I will purchase a tester then go from there.