---
product_id: 18546379
title: "ACDelco GM Original Equipment RC115 (13502509) 20 P.S.I. Radiator Cap"
brand: "acdelco"
price: "€ 24.44"
currency: EUR
in_stock: true
reviews_count: 13
category: "Ac Delco"
url: https://www.desertcart.hr/products/18546379-acdelco-gm-original-equipment-rc115-13502509-20-p-s-i
store_origin: HR
region: Croatia
---

# Raises coolant boiling point OEM GM fit & quality 20 PSI pressure rating ACDelco GM Original Equipment RC115 (13502509) 20 P.S.I. Radiator Cap

**Brand:** acdelco
**Price:** € 24.44
**Availability:** ✅ In Stock

## Summary

> 🛠️ Keep your engine cool, your ride smooth, and your status OEM-approved!

## Quick Answers

- **What is this?** ACDelco GM Original Equipment RC115 (13502509) 20 P.S.I. Radiator Cap by acdelco
- **How much does it cost?** € 24.44 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/18546379-acdelco-gm-original-equipment-rc115-13502509-20-p-s-i)

## Best For

- acdelco enthusiasts

## Why This Product

- Trusted acdelco brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **GM-Approved Reliability:** Engineered to fit most GM models, ensuring seamless OEM replacement and peace of mind.
- • **Heat Management Mastery:** Elevates coolant boiling point to prevent overheating and maintain peak engine performance.
- • **Durable Alloy Steel Build:** Crafted for long-lasting durability under extreme automotive conditions.
- • **Precision Pressure Control:** Maintains optimal 20 PSI to boost cooling efficiency and engine safety.
- • **Preventative Maintenance Essential:** Replace every 5 years to avoid costly overheating issues and maintain cabin comfort.

## Overview

The ACDelco GM Original Equipment RC115 Radiator Cap is a high-quality, 20 PSI rated safety component designed specifically for GM vehicles. It ensures optimal pressure in the cooling system, raising the boiling point of engine coolant to prevent overheating. Made from durable alloy steel and recommended as a GM OEM replacement, this radiator cap supports engine efficiency and longevity while serving as a critical preventative maintenance part.

## Description

ACDelco GM Original Equipment RC115 20 P.S.I. Radiator Cap

Review: Preventative Maintenance Part >>> If not READ BELOW <<< diagnostics for Gen5 Camaro - TL;DR - if you wait too long to replace you *might* experience the symptoms below which this part may fix by replacing it. Otherwise, just replace every 5 years as a preventative maintenance wear item as generally 'accepted' best practice. DISCLAIMER: I am NOT a mechanic, just a guy interested in car stuff. I have a Gen5 Camaro which probably had the original radiator cap. I say "probably" because I got the car used (9 y/o) and the previous owners' did wacky things with the car I won't get into here. Well, mine was probably pushing 12 years by now so I know that's past the limit of this part. Symptoms to know when a radiator cap may be bad: Signs of leaking: As you can see from my pictures, the cap had caked up coolant around it as well as drip stains down the neck on the radiator where the cap sits. I had so many other issues going on with the car, I ignored this for over a year. Car not heating up: Now it's February in the rust-belt and very distressing when the heater isn't working properly. I noticed that the engine was not heating up as fast and taking a very long time to get to around 180° F and then it would drop down to ~176-178° F when I start moving again. I also noticed the engine oil temp and transmission temp never got to their happy place either. Cabin Heat issue: Conversely, the heat blowing in would drop when I'm at a stoplight and get hotter when driving. Analysis / Diagnostics: Facts/observations: - I already had the water pump and coolant flush done 2 years ago so it's less likely that's a cause. - There were no DTC codes. - Coolant level in the overflow tank was okay (up to max) The thermostat is the first place mechanics would go thinking it would be stuck open (this too is a preventative maintenance item but more on that). There are diagnostics to do to check that by checking the temps on the inflow and outflow hoses, etc. but I didn't do that as getting at the thermostat for my car is a very big job (thanks to the LFX engine being mounted longitudinally the thermostat is flush against the firewall rather than being on the side for which it was designed on the Enclave originally). I neither have the tools nor time nor money to do a proper diagnostic so when possible I use my brain and the internet and AI to help me diagnose problems. Approach taken: Parts cannon (justified for wear parts in this case). For this the radiator cap was a cheap and easy fix. I could do in my garage that had a high likelihood of resolving the issue before moving to a more expensive solution. Procedure: I wiped off the filler neck on the radiator, made sure the car was cool and took the cap off, cleaned inside, compared the old and new and then put the new one on. Outcome: Went for a test drive and it appeared to fix my issue! Heating up nice and hot and it even pushed past 183°F and heard the radiator fan kick on to boot to maintain it at temp and all the cluster gauges were reading nominal temps (engine oil, trans fluid) and the heat was blowing consistently into the cabin. Conclusion: Problem solved, for now. The old radiator cap was likely not pressurizing the system as designed, 20 PSI is the rating on the cap and it was probably not able to build to that, so it was probably operating at a lower pressure caused heating performance issues and potentially not creating a vacuum also could cause the introduction of air but I did not do any bleeding afterward so that leads me to believe just related to reduced pressure in the system, resulting in reduced flow within the system that could explain my symptoms that are fluid flow related. (the water pump's rotational speed is directly proportional to the engine speed, so at higher RPMs, the coolant flow rate would have been higher, and the hotter fluid was flowing into the heater core and at idle/stop, the flow slowed down, and the cooler fluid gave me cooler heat). I think I science'd the heck out of this, or at least convinced myself this is how it works, lol. Either way it was kind of sort of, "fun" to figure it out rather than pay someone to do exactly what I did without the Bill Nye explanation. Moral / Lesson: Don't wait like me. Change out this part every 5 years. It could have been far worse if it overheated. A failing radiator cap may put undue wear on the cooling system (potential loss of pressure, vacuum, strain on hoses, radiator, heater core, thermostat, etc.). An ounce of prevention is worth a pound of cure. Once spring/summer rolls around I'll rip apart the intake to replace the thermostat for added peace of mind (FYI, this is I would only get OEM) and probably a bunch of hoses. Thanks for reading hope this helps someone out.
Review: Don't go buying anything else - This was an easy find replacement cap with OEM quality when I needed it quick. If you are in need of one look bo further.

## Features

- Seal and maintain pressure on the cooling system for vehicle safety
- Raise the boiling point of the engine coolant to maintain efficiency
- Fit most models of GM vehicles for expanded coverage
- GM-recommended replacement part for your GM vehicle’s original factory component
- Offering the quality, reliability, and durability of GM OE

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B002E51WJM |
| Automotive Fit Type | Vehicle Specific Fit |
| Best Sellers Rank | #22,615 in Automotive ( See Top 100 in Automotive ) #13 in Automotive Replacement Radiator Standard #279 in Automotive Replacement Engine Cooling & Climate Control |
| Brand | ACDelco |
| Color | Black |
| Customer Reviews | 4.8 4.8 out of 5 stars (540) |
| Date First Available | October 10, 2007 |
| Exterior Finish | Machined |
| Global Trade Identification Number | 00707773568880 |
| Item Weight | 1.76 ounces |
| Item dimensions L x W x H | 2.5 x 2.4 x 1.5 inches |
| Item model number | RC115 |
| Manufacturer | AC Delco |
| Manufacturer Part Number | 13502509 |
| Material | Alloy Steel |
| Model | Radiator Cap |
| OEM Part Number | 13502509 |
| Product Dimensions | 2.5 x 2.4 x 1.5 inches |
| Style | Safety |
| UPC | 707773568880 |
| Vehicle Service Type | GM Vehicles |

## Product Details

- **Brand:** ACDelco
- **Color:** Black
- **Exterior Finish:** Machined
- **Item dimensions L x W x H:** 2.5 x 2.4 x 1.5 inches
- **Material:** Alloy Steel

## Images

![ACDelco GM Original Equipment RC115 (13502509) 20 P.S.I. Radiator Cap - Image 1](https://m.media-amazon.com/images/I/71IdOfX+WpL.jpg)
![ACDelco GM Original Equipment RC115 (13502509) 20 P.S.I. Radiator Cap - Image 2](https://m.media-amazon.com/images/I/61RBAWTKdlL.jpg)

## Questions & Answers

**Q: Is there an oring between this cap and the tank?**
A: This cap screws onto the top of tbe coolant reservoir, or overflow tank, whichever name you want to call it

**Q: Do you have radiator cap in blue**
A: No

**Q: pontiac g8 2008 .. fit ?**
A: yes

**Q: Does it fit a2013 chevy 3500hd with a 6.6 duramax**
A: yes 6.6l duramax

## Customer Reviews

### ⭐⭐⭐⭐⭐ Preventative Maintenance Part >>> If not READ BELOW <<< diagnostics for Gen5 Camaro
*by D***I on February 25, 2024*

TL;DR - if you wait too long to replace you *might* experience the symptoms below which this part may fix by replacing it. Otherwise, just replace every 5 years as a preventative maintenance wear item as generally 'accepted' best practice. DISCLAIMER: I am NOT a mechanic, just a guy interested in car stuff. I have a Gen5 Camaro which probably had the original radiator cap. I say "probably" because I got the car used (9 y/o) and the previous owners' did wacky things with the car I won't get into here. Well, mine was probably pushing 12 years by now so I know that's past the limit of this part. Symptoms to know when a radiator cap may be bad: Signs of leaking: As you can see from my pictures, the cap had caked up coolant around it as well as drip stains down the neck on the radiator where the cap sits. I had so many other issues going on with the car, I ignored this for over a year. Car not heating up: Now it's February in the rust-belt and very distressing when the heater isn't working properly. I noticed that the engine was not heating up as fast and taking a very long time to get to around 180° F and then it would drop down to ~176-178° F when I start moving again. I also noticed the engine oil temp and transmission temp never got to their happy place either. Cabin Heat issue: Conversely, the heat blowing in would drop when I'm at a stoplight and get hotter when driving. Analysis / Diagnostics: Facts/observations: - I already had the water pump and coolant flush done 2 years ago so it's less likely that's a cause. - There were no DTC codes. - Coolant level in the overflow tank was okay (up to max) The thermostat is the first place mechanics would go thinking it would be stuck open (this too is a preventative maintenance item but more on that). There are diagnostics to do to check that by checking the temps on the inflow and outflow hoses, etc. but I didn't do that as getting at the thermostat for my car is a very big job (thanks to the LFX engine being mounted longitudinally the thermostat is flush against the firewall rather than being on the side for which it was designed on the Enclave originally). I neither have the tools nor time nor money to do a proper diagnostic so when possible I use my brain and the internet and AI to help me diagnose problems. Approach taken: Parts cannon (justified for wear parts in this case). For this the radiator cap was a cheap and easy fix. I could do in my garage that had a high likelihood of resolving the issue before moving to a more expensive solution. Procedure: I wiped off the filler neck on the radiator, made sure the car was cool and took the cap off, cleaned inside, compared the old and new and then put the new one on. Outcome: Went for a test drive and it appeared to fix my issue! Heating up nice and hot and it even pushed past 183°F and heard the radiator fan kick on to boot to maintain it at temp and all the cluster gauges were reading nominal temps (engine oil, trans fluid) and the heat was blowing consistently into the cabin. Conclusion: Problem solved, for now. The old radiator cap was likely not pressurizing the system as designed, 20 PSI is the rating on the cap and it was probably not able to build to that, so it was probably operating at a lower pressure caused heating performance issues and potentially not creating a vacuum also could cause the introduction of air but I did not do any bleeding afterward so that leads me to believe just related to reduced pressure in the system, resulting in reduced flow within the system that could explain my symptoms that are fluid flow related. (the water pump's rotational speed is directly proportional to the engine speed, so at higher RPMs, the coolant flow rate would have been higher, and the hotter fluid was flowing into the heater core and at idle/stop, the flow slowed down, and the cooler fluid gave me cooler heat). I think I science'd the heck out of this, or at least convinced myself this is how it works, lol. Either way it was kind of sort of, "fun" to figure it out rather than pay someone to do exactly what I did without the Bill Nye explanation. Moral / Lesson: Don't wait like me. Change out this part every 5 years. It could have been far worse if it overheated. A failing radiator cap may put undue wear on the cooling system (potential loss of pressure, vacuum, strain on hoses, radiator, heater core, thermostat, etc.). An ounce of prevention is worth a pound of cure. Once spring/summer rolls around I'll rip apart the intake to replace the thermostat for added peace of mind (FYI, this is I would only get OEM) and probably a bunch of hoses. Thanks for reading hope this helps someone out.

### ⭐⭐⭐⭐⭐ Don't go buying anything else
*by S***K on December 29, 2025*

This was an easy find replacement cap with OEM quality when I needed it quick. If you are in need of one look bo further.

### ⭐⭐⭐⭐⭐ Radiator cap
*by B***D on December 13, 2024*

Value, fit great, easy on off.

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*Product available on Desertcart Croatia*
*Store origin: HR*
*Last updated: 2026-03-14*