10 Helpful Steps to Repair a Brake Reservoir Cap
Your brake reservoir cap is the cap that you can open and close in order to refill your brake's supply of brake fluid every time. However, there are times when the cap gets damaged, necessitating repair or replacement. You can go about cap replacement as soon as you've determined what's wrong with it or if it's the source of your reservoir leaks. You can also do the fixing when you check your brake fluid or if the brake light on your dashboard is on (indicating a leak or low brake fluid level). You absolutely must get your reservoir cap fixed post-haste before it causes your brake fluid to completely empty your reservoir.
Difficulty Level: Moderate
What You'll Need
- Brake fluid
- Hand soaps
- Car manual
- Brake fluid cap replacement
Step 1: Go to the brake master cylinder located under the hood and at the back of the engine compartment over the driver's side of your vehicle. Try to visualize where your brake pedal would be if its assembly went all the way through the engine.
Step 2: The brake master cylinder is a six-by-two-inch metal rectangle with a reservoir made of plastic and a rubber cap up top while it has small metal tubes connected to it. The cap is the part we're supposed to replace or fix.
Step 3: If you're not sure if you've located the master cylinder and its reservoir cap, check your user's manual. The rubber brake fluid reservoir cap will usually read "Use only DOT 3 or 4 brake fluid from a sealed container".
Step 4: Take note that new cars have translucent reservoirs where you can see the fluid level without cap removal and level indicators. Vintage cars from 1980 and earlier have metal cylinders that require you to remove the top to check the fluid level.
Step 5: A rubber cap with a ruined or loose screw might simply need a quick fix like spooling extra threads on its bottom to tighten it up when screwed close. To fix it completely, get an aftermarket replacement cap.
Step 6: Vintage reservoir caps for brake fluid have steel tops held by metal clamps. They require screwdrivers in order to pop them off. If they're damaged due to warping or corrosion, outright replacement is your best bet.
Step 7: Add brake fluid to the full line of your reservoir with the correct brake fluid type for your vehicle. Check your user's manual and the rubber reservoir cap's instructions on which brake fluid type your automobile can take.
Step 8: Most cars follow the Department of Transportation's requirement of using 3 or 4 brake fluid. If your reservoir has two parts, both halves should be filled up. Remember that brake fluid is toxic, so keep it away from your hands and eyes.
Step 9: Don't spill the brake fluid on the ground or on your car paint either. Carefully dispose of the containers as well, making sure that there's no leftover brake fluid left to get into contact with. Wash your hands after handling that fluid.
Step 10: A completely empty brake master cylinder will have the pedal going to the floor. You should bleed the brakes first before driving a car that has run out of brake fluid. Get your mechanic to flush the braking system and refill it if faced with this situation.