Bleeder valve or Brake fluid reservoir

whaleplane · Post by **whaleplane** » 15 Jan 2011, 22:15

I'm going to change my front brake pads for the the first time tomorrow!

I've read a few places that say you need to remove the brake fluid reservoir to allow for the fluid to push back when the piston is compressed. I've also read that the brake bleed valve(on the back of the caliper) needs to be removed to allow the piston to be compressed. Do I need to one or the other or both? If it's the bleed valve how does it come off?

Thanks.

Post by **JDS60R** » 15 Jan 2011, 22:26

This sounds like its your first time with this type of brake repair. You should do this with an expert the first time.

TexasCoder · Post by **TexasCoder** » 16 Jan 2011, 14:02

Just take the cap off the reservoir, as you push the caliper piston back, keep an eye on the fluid in the reservoir and make sure it does not spill out. If it starts to get close to the top, just use a syringe and siphon some of the fluid out. You don't need (or for that matter want) to remove the bleeder valve. Just remember to top off the brake fluid, if you siphoned any out, to make sure the brake fluid is at the proper level.

You only use the bleeder valve to "bleed" the brakes. Jump on youtube.com and view a few videos on "brake pad replacement" and "bleeding brakes" to get a feel for things.

Just take it slow and steady and you will be fine.

Post by **writer100** » 16 Jan 2011, 14:12

The rationale behind opening the bleed screw when pushing back the piston is to prevent dirty brake fluid from being pushed into the ABS system. It also prevents the overflow at the reservoir of which you speak.

There are different schools of thought on this. Some will claim that opening the bleed screw is criitcal, and others say it is not.

Certainly if you do not open the bleed screw, you should ensure that adequate space exists in the reservoir for the displaced fluid.

Post by **JDS60R** » 16 Jan 2011, 14:18

Opening the bleeder screw while compressing the piston is suggested as a good practice.

By opening the bleed screw at the caliper you avoid pushing contaminants that have settled in the caliper back up into the tight passageways of your ABS unit. Close the bleeder as soon as the caliper is compressed. Any excessive tension while pressing the piston back in the caliper shows a need to inspect and replace or rebuild the caliper. All slides should be inspected, cleaned and lubricated properly.

Top off the fluid in the MC res when finished. You must use proper fluid and lubricant to avoid harm to the system.

whaleplane · Post by **whaleplane** » 16 Jan 2011, 20:17

Thanks for the advice. I thought I had heard/read a few different theories. Good news is that the brake pads are on and working.

I'm a huge proponent of asking questions, large or small, before diving into projects. It saves a lot of"oh crap what do I do now" moments. Thanks again for the advice.

TexasCoder · Post by **TexasCoder** » 16 Jan 2011, 20:31

Good to hear! I am glad you got 'em installed, and your happy with the outcome. This forum is awesome, there are a lot of knowledgeable folks here, and posts that have saved my butt more than once!