How To Check & Replace a T25 Reservoir cap

Mark shows us how to check and replace a T25 Reservoir cap.

(00:00) Welcome to Just Kampers. In this video, I'm going to show you how to check your cooling system header tank cap on a T25. First, we make sure the engine is absolutely stone cold, and then we remove the pipe that goes between our header tank cap and our overflow tank, and then we pick one of the big cooler pipes and give it a good squeeze. I can actually hear air coming out of the spout that's leaking. We don't want that, so we need to change that, so let's put our replacement cap on, we'll do the

(00:33) same test, give it a good squeeze, and now I can't hear any air! The purpose of this header tank cap, is to regulate our cooling system's pressure as the engine warms up and our coolant expands it causes a rise in pressure, when it reaches one bar or 14.5 PSI, the valve in this cap will open and allow and flow into our overflow catch tank now when the engine is then switched off and allowed to cool the secondary valve in this cap will open and allow fluid to return back to our cooling system as you can see the black one on the left has

(01:06) two visible valves now, these type of caps have quite a high failure rate, and then you see the new one has a different type of pattern, but it does still contain two valves. The new cap is a direct replacement, and it's made in Germany by a company called Blau, which actually manufactures for VW.  Follow us on YouTube, Facebook Instagram and check us out at JustKampers.com. Thanks for watching.