Take the 2-minute tour ×
Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It's 100% free, no registration required.

Is it possible to add oil to the hydraulic disc brake reservoir to increase the stiffness of the lever, without bleeding the brakes?

share|improve this question
add comment

1 Answer

up vote 7 down vote accepted

There are 2 types of hydraulic brake systems, referred to as open systems and closed systems.

Open systems have a reservoir, with a cap, usually on the brake lever, above the master cylinder. These systems, when proper care is taken, can have fluid added, or hoses trimmed without rebleeding the brakes.

Closed system brakes, like most older Hayes brakes, (HFX-9, Nine, Original Hayes) can't add fluid, because the only access to the fluid reservoir is through the bleed ports.

Whether you can add fluid or not, if your brakes need to be bled due to water or air contamination, then simply adding fluid will not fix your problem. If you have a simple fluid leak, with no contamination, then it may work, although you should also look for the source of the leak, and fix it.

Bleeding a brake is not a difficult task, and usually requires few, if any special tools. If your brakes need to be bled, look up the manual, and give it a go. You can't really do any permanent damage, and if you follow the directions, you shouldn't have any trouble, anyhow.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.