how do i bleed the air from my cooling system? i believe that air bubbles are making my add coolant light come one.

 

S4 or S5? For an S4, fill the cooling system via the radiator cap on the radiator. Then remove the cap on the water pump neck and fill there. Replace and squeeze-release the upper rad hose a few times. Repeat.

For an S5, fill via the radiator fill neck. Squeeze rad hose, refill. Repeat. Repeat. Repeat. They're a b*tch to get completely bled.

Also make sure that you engine's not drinking coolant - you should be able to fill the engine, fill the overflow tank, and be mostly done. If you level perpetually falls, it could mean your coolant seals are going (which would cause low compression, which would cause flooding).

Do a search and see if you can't figure out how to test for bad coolant seals

Brandon

 

I believe there's a bleeding nipple somewhere on the radiator, check the FSM, if not, look around, I think it's on the passenger side towards the top of it.

 

True, but there's still a "droop" in the upper rad hose that prevents air trapped in the top of the water pump output neck from ever escaping.

If ya wanna get dirty, the best way I've found is to remove the t-stat, put everything back together, fill the engine up, replace the t-stat, and fill through the upper rad hose, stopping when coolant starts coming out of the output neck. Then have an assistant fill the rad while you open an 'air bleed' through the upper rad hose->neck junction. When water comes out, clamp that puppy and your system's DONE.



But that's the hard way.

Brandon