If you're diving into the world of cooling systems, you’ll want to pay attention to the HPS Performance 25/32" High Temperature Reinforced Black Silicone Cap. This isn't just any cap; it’s built to handle the heat and pressure that come with your engine's cooling system. I’ve used these caps myself, and let me tell you, they stand up to the test.
Unlike those flimsy vacuum caps that can barely handle a little pressure, this silicone cap is reinforced with a tough 3-ply polyester webbing. That means it can take the heat—up to a whopping 350°F (that’s about 177°C for those who like metrics). Whether you're dealing with coolant, water, or even air, this cap won't let you down.
It’s compatible with a bunch of applications too: turbocharger bypass valve ports, vacuum ports, throttle body water ports, and heater cores are all fair game. Just make sure you steer clear of fuel or any petroleum-based products; this cap isn’t designed for that kind of abuse.
Now, let’s talk dimensions. The inside diameter comes in at 25/32" (20mm), and the overall length is 1-5/8". With a wall thickness of 4mm, you can trust that this cap is built to last. Plus, it’s UV and ozone resistant, so it won’t break down when exposed to the elements.
In short, if you're looking for a reliable, heavy-duty cap that can handle the rigors of your cooling system, the HPS silicone cap is a solid choice. It’s got the specs to back it up and the durability you need for long-term use.
⚠ WARNING:
Cancer and Reproductive Harm
https://www.P65Warnings.ca.gov

HPS Performance Products is a leading manufacturer of aftermarket performance parts, fabrication components, and silicone hoses. HPS serves a number of different industries, including automotive, aerospace, construction, commercial truck/bus, marine, agricultural, turbo diesel, off-road, performance racing, general manufacturing, and water treatment. The company’s ability to fabricate custom-shaped multiply silicone hoses make it ideal for a wide range of applications. The multiply carcass makes HPS’ hose perfect for coolant and turbocharged pressure applications while the fluoro-silicone-lined hoses make it safe to be used with petroleum-based oil and fuel.
HPS Performance Products is committed to meeting its original goals of producing quality parts at competitive pricing and providing customer service responses in a personal, timely manner. All HPS products have been thoroughly tested on the dyno and track, and meet or exceed SAEJ20 standards. The HPS staff has solid expertise in the silicone hose department, which allows them to deliver standard size silicone hoses with same-day shipping. HPS’ highly skilled and knowledgeable team, paired with the latest state-of-the-art technology, ensures the brand’s continued success and reputation as a premier manufacturer in the industry
HPS Quality Silicone HosesHPS Performance Products specializes in and is best known for manufacturing multi-application silicone hoses. HPS silicone hoses are carefully crafted from only the highest quality 4-ply reinforced high-temperature material. The hoses are available in the following varieties: straight coupler, 1-foot tube, 3-foot coolant tube, charge air cooler hose (CAC), hump coupler, reducer couple her, 45-degree elbow coupler and reducer, and 90-degree elbow coupler and reducer.
HPS Performance Products also carries performance silicone vacuum hoses and silicone heater hoses. You can choose silicone hoses in both standard inch and hard-to-find metric sizes. Stainless steel T-bolt clamps are available to match with the silicone hoses as well. In order to meet the high demand and shorten the turnaround time for its silicone hoses, up to 90 percent of the product is already in stock and ready to ship or pick up from HPS authorized dealers like Vivid Racing.
HPS Performance Products at Vivid RacingVivid Racing carries a comprehensive lineup of HPS Performance Products for a number of different makes, models, and applications. Our extensive inventory of HPS parts includes aluminum tubing, cold air and short ram intakes, vacuum lines, hoses and clamps, intercooler pipes, radiator caps, and much more! If you have any questions regarding the items listed above or have fitment concerns, please contact our expert sales team at (480) 966-3040. We are here to help you through the entire purchase process and make it a pleasant experience.