Front Brakes Locked up after Recall

[wroc1]

A couple of months ago I had the brake recall done on my 2013 F6. Saturday morning I went for a ride. After 5 miles I was going through the gears just reaching 50 mph when my front brakes engaged. Talk about a wake up call. Pulled in clutch and nose dove harder. Dumped clutch and gases it to get off road. Had to bleed front left brake to get bike on trailer. Dealer couldn't find anything and blamed on slightly over filled reservoir which wouldn't have actuated brakes. Bike still at shop because I don't trust braking system. Anyone seen this before?

[stroguy]

Is this your first ride since the recall work?

[wroc1]

Is this your first ride since the recall work?

No. Have had several rides with no issue.

[stroguy]

I heard you the first time.

JK


I am no hydraulic specialist by far but the theory is simple and if you are not compressing the fluid the calipers should not squeeze the brake disc. So, if the caliper did not release from the last braking I could see a heat issue causing a partial freeze of the pad to the rotor.

There will be someone that knows way more than me to pipe up.

Larry?

[Wing'n it]

If there is too much fluid in the reservoir it sure could apply the brakes. If the fluid expands it has to go somewhere so if the system is overfull it will push past the master cylinder and put pressure on the system. Question is who overfilled it, the dealer that did the work?

[stroguy]

Is the fluid not heat stable to prevent that issue?

[Wing'n it]

Is the fluid not heat stable to prevent that issue?

To an extent it is but brake fluid needs room that why we have the rubber bellows under the cap, to seal out moisture but still let the fluid expand and contract. If you get brake fluid hot enough it will actually boil and cause brake fade or mushiness. If the system is too full it will expand and has to go somewhere and it would not take much on the F6 to be pushing on the rotors. Check the level in the reservoirs (clutch and brake) and you should see a "white floater" at the top of the window if you can't see it, it's too full.

[shooter]

If there is too much fluid in the reservoir it sure could apply the brakes. If the fluid expands it has to go somewhere so if the system is overfull it will push past the master cylinder and put pressure on the system. Question is who overfilled it, the dealer that did the work?

Exactly right. With every application of the brake the fluid gets hotter and expands. Once there is no air space left in the system it starts pushing the pistons out in the caliper. That makes more friction getting the fluid even hotter till what happens to the OP. Brakes can't apply themselves. Once the fluid level is adjusted it should be fine.

[shooter]

No. Have had several rides with no issue.

You have to remember we are deeper into the summer so everything is hotter. Fluid is hotter to begin with and road temps are hotter imparting even more heat into the system. I've seen this problem on automobiles many times. People that have their oil changed at quick lubes have this issue sometimes. The minimum wage idiot that tops off your fluid does exactly that. Fills the reservoir to the top. That master cylinder has a MAX line on it. It should never exceed that. It only takes approx a tablespoon of fluid to stop your vehicle.

[Steve 0080]

There is also a vent in the resorvior for over flow to escape in these type situations. However I have never heard of this happening.