G.A.S. BMW 1.2 Bar Cooling System Cap
German Auto Solutions 1.2 Bar Coolant Cap

Catastrophic cooling system failures are a fairly common problem on BMW vehicles. The problem is related to the cooling system maximum relief pressure that BMW has chosen to run, coupled with an almost entirely plastic set of cooling system components.

Most BMW vehicles manufactured between 1982 and 2006 run a cooling system vent pressure of 2.0 bar (29 psi). The problem is that the cooling system components are barely rated to handle that pressure when brand new. As the plastic parts heat cycle hundreds of times while exposed to the degrading effects of heat and coolant, they lose some of their strength. The result can be a ruptured part somewhere in the cooling system.

As you can see from the pictures on the left, ruptures can occur in the radiator tanks, expansion tank, thermostat housing and coolant hoses. Not only can a failure leave you stranded somewhere that you would rather not be stranded, but these engines are very prone to cylinder head warping and cracking when severely over heated. The number one cause of very expensive cylinder head failures is severe over heating during a cooling system failure.

So what is the solution? The system does not need to run that high of a pressure. In fact the industry standard for cooling system pressure is 1.0 to 1.4 bar. After doing extensive research and beta testing on several BMW engines, we decided on an optimum pressure of 1.2 bar. This pressure is high enough to maintain OEM pressure specifications up to 126 degrees Celsius  (260F), which means that our cap will not alter your  cooling system efficiency in any way. Apparently even BMW has seen the light, since most current BMW models now come equipped with a 1.2 bar cap. 

Our cap will limit the maximum coolant pressure to 1.2 bar (17.5 psi) instead of the OEM spec of 2.0 bar (29 psi). Even something as simple as overfilling the coolant recovery tank a little higher than the recommended level will result in potentially damaging pressures when using the stock 2.0 bar cap.

We want to be very clear... cooling system components can fail due to cracking even at normal operating temperatures and pressures. Our cap will not guarantee you will never experience a cooling system component failure, but it will drastically reduce the chances of catastrophic ruptures.

The German Auto Solutions 1.2 bar Cooling System Cap uses 100% original BMW internal components that have been recalibrated to vent at 1.2 bar. The top of the cap is CNC machined from 6061 aluminum alloy, CNC engraved and then color anodized to prevent corrosion and enhance beauty. This cap is not just an inexpensive solution to a potentially very inconvenient and very expensive failure, but is a nice dress up item as well. German Auto Solutions will soon be offering matching billet oil filler, power steering filler and oil filter caps for those who would like a complete set of high quality engine bay dress-up items.

If your BMW is more than 5 years old it's a good idea to replace the cooling system cap as part of a regular cooling system maintenance routine. Why take a chance with your expensive BMW cooling system by using the OEM 2.0 bar cap. Get your German Auto Solutions 1.2 bar replacement cap today.

The German Auto Solutions 1.2 bar coolant cap fits many BMW models manufactured from 1982 to present. Use the application list link below to verify fitment for your vehicle.

Click on the images on the left to enlarge the image size.

German Auto Solutions 1.2 Bar Coolant Cap

The German Auto Solutions 1.2 bar coolant cap is available in black or red at an
Introductory Price of $34.95 plus shipping.

Regular Price: $47.95

Before you purchase the coolant cap make sure that you have:

G.A.S. 1.2 Bar Coolant Cap

Price: $34.95 - $36.95


Our 1.2 Bar Coolant Cap is now available as a "Combo Pack" with our DISA Repair Kit. SAVE $10.00 on the pair!

Price: $104.90