Front Brake Mistry

Well, a new to me issue.

Last weekend I pushed the GRiSO and Scura out of the shop for a much needed washing.
When grabbing the front brake on the GRiSO the lever went nearly to the grip and was very mushy.
Last service was back in September before the Kentucky Rally. Brakes, front and rear, and clutch.
No issues what so ever on the four day trip.
Being a late afternoon project, the washing, I decide to circle back to it on my next weekend off.

So, weekend comes around.

Step one: General Visual Inspection.
No leaking or obvious damage. Lever still mush.

Step two: Bleed the brakes.
What a surprise. Right caliper was producing a few bubbles. Hmmm . . . ?
More surprising. Left caliper was producing LOTS of bubbles. Shocked !?!

Step three: Tap, tap, tap with a dead blow mallet, to get the last few bubbles to rise, and continue bleeding.
More tiny bubbles, then nothing but clean fresh fluid on both sides.
Lever is firm. Test ride confirms front brakes are good.

Take the wife's advise. It's a nice sunny day, go for a ride.
Totaled a tick over two-hundred miles tear assing around Southern Indiana, zero problems.
Bike is awesome. My faith is renewed.

Mostly.

WTF and how did air get into the system? No clue on my part.

The plastic over braid on the brake lines is chipping and cracking. That's more of a cosmetic issue and wouldn't allow air into the system. If it was fluid would be coming out as well. I'll head over to Earl's Performance Plumbing on Gasoline Alley to have a new set made up in a few weeks.

Any ideas? Anyone?

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They do clean up nicely.

The GRiSO and Scura do make great stablemates for sure!  Adding a Norge or Stelvio for the trifecta!

Out of curiosity what pipe do you have on the GRiSO?

PJPR01, nope, not hurting for Guzzi stable mates or projects.
Currently doing a little refresh on a '73 Police Eldorado.
Next on the lift will be a '67 V700.

GRiSO is running an Arrow muffler with stock headers and pretzel with a Beetle Map.

my guess is the pads wore down and the reservoir was low enough to suck in some air as the pads wore.
if you have adjusted your handle bars and caused the reservoirs to no longer be level, it can be challenging to get the proper amount of fluid in them, which can also add to the problem

...or the FB Master Cylinder has failed and needs to be rebuilt or replaced.

It happens.

I'll give it another look see on my upcoming days off.

Previously inspected and no noted deterioration. Fluid was still clear and bright, above minimum level.

We'll see.

Just to add in it might be the rubber master gasket assy has a breach............. when full of fluid if that is the case you might see minor weeping at the two surfaces.

ciao