bing tracking image
  1. Accessories and Parts
  2. Demco
  3. Brake Actuator
  4. Master Cylinder Parts
  5. Caps
Demco Actuator Cap for Master Cylinder

Demco Actuator Cap for Master Cylinder

Item # 3876
Our Price: $20.01
You Save: 10%
Accessories and Parts
Orders above $99 qualify for Free Shipping
Shipping Weight: 0.03 lbs
In Stock
3876 - Caps Demco Brake Actuator
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

Need help with installation?
Locate installers near me
1-800-940-8924 to order Demco accessories and parts part number 3876 or order online at Free expert support on all Demco products. Great prices and Fastest Shipping for Demco Actuator Cap for Master Cylinder. Accessories and Parts reviews from real customers.
  • All Info
  • Reviews (24)
  • Q & A (0)
  • Videos (1)
  • Photos
  • Why etrailer?

Demco Accessories and Parts - 3876

  • Brake Actuator
  • Master Cylinder Parts
  • Caps
  • Demco


  • Replaces the actuator cap for your Demco hydraulic coupler
  • Made in the USA

03876 Demco Actuator Cap for Master Cylinder

California residents: click here

Video of Demco Actuator Cap for Master Cylinder

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Review of Demco Brake Actuator Parts - Replacement Actuator Cap - 3876

Ellen: Hey everyone. I'm Ellen 00:00:01 here at and we're going to be taking a quick look at the Demco actuator master cylinder cap. So if something happened to that original cap, it got lost or broken off, this is going to be that direct replacement from Demco to get you back to working with that brake actuator. So you can see it's going to be kind of an automotive style cap, has a rubbery gasket on the inside to help prevent any kind of leaks or contamination of your brake fluid and should get you back to rolling. The rough size for that threaded portion is about an inch and an eighth, so it should fit on anything that has that same size. That's just roughly me measuring it with my ruler, so it might be a little bit different for your actual brake actuator.

But that's going to do it for our look at the replacement cap for your master cylinder on your Demco brake actuator. Thanks for watching.

Customer Reviews

Demco Actuator Cap for Master Cylinder - 3876

Average Customer Rating:  4.8 out of 5 stars   (24 Customer Reviews)


fit perfectly and works


Delivery took a little longer than expe cted.


Perfect replacement for my trailer actu ator


Great seller Great follow thru Fast d elivery


It took almost a week to get the cap in the mail.
Thank you for the cap, it fits perfectly.


Good master cylinder cap. Thread off this Demco cap get damaged because of the poor design of the master cylinder, not because of the quality of the cap. The galvanized metal thread on the master cylinder starts rusting in combination with brake fluid and age, this damages the plastic thread on the cap.


It was a small product but they treated me like it was a big order. I damaged my cap and needed a new one for the Labor Day weekend for my trailer brakes. They had an issue locating the part at first but called to keep me informed and got me the part in time!


It was the perfect cap for my brake actuator assy .


Came in on time and fit perfectly. The old one was on 18 years and became brittle over time.
When it was removed some of the cap threads broke off and had to be removed before installing the new cap.


It took a long time to get to us, but it fit perfectly. We were using aluminum foil. Much more secure now.




Part was perfect and was fast shipping. Will buy from them again.


Looks to be a fine replacement cap. Very fast shipping!


perfect OEM replacement.


customer service was great on replacing this broken part


Worked perfectly. Thank you for the speedy service



Cap fit great. Very happy with service and follow up email.








It work good



See what our Experts say about this Demco Accessories and Parts

Do you have a question about this Accessories and Part?

  • Why

    At we guarantee:
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate accessories and part information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Employee Kathleen M
Installed by:
Kathleen M
Employee Wilson B
Updated by:
Wilson B

At we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.