Crappy brake feel -- Help!

[AremRed]

Hey guys, bought a 2016 FJ-09 a couple months ago and put about 3000 miles on it since. Other than the stock suspension (shit) and the throttle response (crazy without a flash), the biggest thing I've started to notice is crappy brake feel.

I've bled my brakes properly but the lever feels different the first time I pull it versus the second time....the feel is much better on the second time after I "pump" the lever. 

I'm guessing this is due to the master cylinder not being great? Or is this the brake line flex I am feeling? Has anyone else experienced this?

[BBB]

Brake line flex would be a consistently poor feel to the brakes. If the pressure comes up when you pull on the lever the second time, you probably have a big bubble trapped in the lines, which are sometimes difficult to clear. Pull the lever in tight, then tie a strap or cable tie around the lever and leave it overnight. The increased pressure makes the bubble smaller and more likely to work its way out.

[Stew]

Thats how I always do it after bleeding brakes, pump the front brake lever a few times, then cable tie it as tight as possible to the bars, crack the master cylinder top a wee touch as well, and leave overnight.

[DavidS]

or if the brake lines have never been replace (or you aren't sure if they have) replace them. Stainless steel lines aren't much more money, and they perform better too.

[dpippin]

Maybe you just need new brake pads. I you do decide to replace them make sure you condition the rotors by lightly sanding with Scotch Brite (or similar) pads so the new pads will seat in properly.

[Tripletrouble]

On 8/20/2020 at 4:05 PM, dpippin said:

Maybe you just need new brake pads. I you do decide to replace them make sure you condition the rotors by lightly sanding with Scotch Brite (or similar) pads so the new pads will seat in properly.

This wouldn’t explain the first and second pull being different. It’s more likely air compressing in line. Wipe all line joints with a paper towel to check for any fluid/leaks. Take off brake lever and see if there is any fluid inside lever housing (master cylinder) as there is a seal that can leak behind the piston which can go unnoticed. Tying brake lever pulled in overnight should remove air, but if there’s a leak the air will return.

[Lone Wolf]

On 8/21/2020 at 10:30 AM, Tripletrouble said:

This wouldn’t explain the first and second pull being different. It’s more likely air compressing in line ...

Exactly. And if the previous suggestions did not help, here is something from an ancient Honda 750 Clymer manual on brake bleeding:

"If the system is difficult to bleed, tap the master cylinder and caliper housing with a soft mallet to help release air bubbles trapped in the system" (that is in a section talking about using a MityVac to draw brake fluid out at the caliper).

[betoney]

9 minutes ago, california said:

Exactly. And if the previous suggestions did not help, here is something from an ancient Honda 750 Clymer manual on brake bleeding:

"If the system is difficult to bleed, tap the master cylinder and caliper housing with a soft mallet to help release air bubbles trapped in the system"

I use the same method myself, I use a wooden dowel or mallet wooden handle and start at the caliper and work my way up to the master cylinder tapping steadily. 

[Tripletrouble]

14 minutes ago, california said:

Exactly. And if the previous suggestions did not help, here is something from an ancient Honda 750 Clymer manual on brake bleeding:

"If the system is difficult to bleed, tap the master cylinder and caliper housing with a soft mallet to help release air bubbles trapped in the system" (that is in a section talking about using a MityVac to draw brake fluid out at the caliper).

Yes, that can work. Another couple of ways, but only if your confident. 1 Slightly crack open the line connector at the master cylinder momentarily . 2. Reverse bleed. Use a big syringe filled with brake fluid. Attach a piece of pipe from syringe to bleed nut, crack nut open and use syringe to push fluid up. This is great if your fitting new empty lines. However, as previous, ask yourself why you have air in the system in the first place....

[crempel]

Because of the ABS system, air bubbles can easily get trapped in some of the plumbing associated with the ABS. One of the key things to do when bleeding any bike that has ABS is to activate it after you’ve done your bleeding and then bleed it again. Activating the ABS will push the bubbles out of the pump and housing that the fluid is trapped inside and allow you to fully believe the system. It’s not particularly hard to activate the ABS. You don’t have to do it at high speeds. Just find yourself a gravelly area and carefully apply the brakes until you scared the tire or tires a little bit and feel the pulsing. You can let go immediately and still retain full control. Do this at your own risk and don’t call me if your biff your bike. Once you’ve done this a few times, Re-bleed the system and it should help. Because most of the ABS plumbing is set in a horizontal manner, it can be particularly hard to get the bubbles out of there without forcing them out via the ABS pump.