Front brakes hard and soft

[greenrider]

Hi

it just started that the lever for the front brakes can be the way they should be then be very soft or hard. Which means the lever hardly moves when applying the brakes or lever can go almost to the handle bar. Why is this. I had changed the brake lines to stainless 3 years ago but this just started in the last 6 months. 

 

1997

R1100RT

[Michaelr11]

First thing I would do is a brake fluid bleed on that front circuit to make sure there is no trapped air.  Should take you about 10 or 15 minutes.  When was the last time you bled the brakes?

[dirtrider]

20 hours ago, greenrider said:

Hi

it just started that the lever for the front brakes can be the way they should be then be very soft or hard. Which means the lever hardly moves when applying the brakes or lever can go almost to the handle bar. Why is this. I had changed the brake lines to stainless 3 years ago but this just started in the last 6 months. 

 

1997

R1100RT

 

Evening greenrider

 

There are a few reasons for what you are experiencing.

 

The most common is the master cylinder piston not fully returning to it's out-stop. If the piston doesn't FULLY return then the piston won't uncover the small fluid take-up port in the bottom of the  reservoir & THAT traps unreleased fluid in the master cylinder bore.

 

As the brakes (and brake fluid) heats up that can make the brake application very aggressive with a very short lever stroke & grabby barking. Then as the fluid cools the master cylinder can't get any make-up fluid so you THEN have long mushy lever pull & weaker braking.

 

So first thing to check is the master cylinder piston for fully returning to it's out stop (every time), check the lever for sticking & being adjusted properly, basically make sure that the lever & master cylinder is working as intended (every time).

 

The other (less likely place) is a problem in the ABS modulator causing a varying hydraulic function in the front braking circuit. This is difficult  to diagnoses & difficult to isolate.

 

If the short stroke on the lever & more aggressive braking is normal & your problem is just an occasional  longer stroke & mushy braking then look at your front wheel bearings as possibly being loose. A loose front wheel can allow the brake rotors to kick the brake pads back & cause a longer lever travel &  mushy feeling braking until the brake pads contact the brake rotors & stabilize them.

[greenrider]

Thanks 

So I thought I should let you guys know where my problem was. 

Like DR mentioned that I should make sure the master cylinder is coming out all the way. It was the hinge of the brake lever that was causing it from coming out all the way. So I took it all apart and clean the bushing and the hole it fit in and everything works again.