Rear Brake Problems : LUSENET : MV Agusta F4 : One Thread

Anyone had problems with the rear brakes of their F4S 1+1? Mine have gone out for the third time now. They do not leak, yet I lose the pedal completely. I just had them serviced for the same problem this past week and was heading out for a Labor Day event and noticed the same situation. According to the dealer, Cagiva reports this to be a common problem. In addition, I have not been able to get an answer on the length of Warranty. Anyone have an idea?

-- Tom Summitt (, August 30, 2003


You better have to ask, if thereīs is anyone who has NO problems with th rear break.

For me itīs a heat-problem.

Will get a break-update the next days from me dealer be warranty, which lasts 2 years here in germany.

regards Roland

-- roland (, August 31, 2003.

I solved my rear brake problem by changing the fluid to Brembo 660; I wrapped the exhaust with Thermo-tec wrap; covered the master cylinder lines, brake master cylinder and reservoir with Thermo-tec adhesive foil insulation and replaced the master cylinder cover with a CF unit.

I don't know which step fixxed the problem--but I have rear brakes now that work. I'm going to build a kit to adapt the Brembo 4 piston rear caliper and small 200mm rotor after I get the front brakes dialed in.

-- martin (, August 31, 2003.

You will have problems with the rear brake if you own an MV F4 it seems. Mine doesn't work completely. But I don't really care because I don't use it. It might work well enough to hold the bike on a slight incline, that's it.

I wrapped my exhaust near the rear brake parts, but that didn't help. Looks like you'll have to take more of the steps outlined above. I'm using Motul RBF600 fluid and it doesn't help. There is a Castrol fluid that boils at some seriously high temperature, like 500 degrees F. That might help.

-- Andy Ruhl (, August 31, 2003.

I had same problem , when I picked up bike ( secondhand) the brake lever was touching fairing, I adjusted up rear brake without bleeding it , big mistake ,!! The next time I rode it the rear break locked up the back wheel , not a nice experience ! Research on various internet lists and with dealers lead me to go down Castrol SRF route , wet boiling point 500 degees , but still hydroscopic type fluid . No problems now. Only problem is that in Uk you can only get SRF in 1 litre cans at Ģ45 and once opened it can absorb moisture leading to lower boilng point and resulting problems . I don't understand why everyone doesn't have problem with brake which leads me to believe that MV started using different brake fluid . On the evo3 they have moved the reservoir up underneath the seat away from the exhaust.

-- Daryl Yemm (, September 01, 2003.

Any of you EVO III owners have a picture of that rear brake reservoiur relocation????

Might save "someone" a little time and frustration...


-- Scot Hennon (scot/, September 01, 2003.

Don't have a picture, but I had a close look at an Evo 3 at the importer's last week - the reservoir is now fixed on a bracket at the rear of the motor, just underneath the the base of the fuel tank and in front of the spring/damper unit; must be even more fun trying to get access!?!

Meanwhile, I think I've found the definitive cure. I tried most of the mods above with limited success, but finally repostioned the reservoir under the tail section just like on a lot of jap bikes I've had. It was the simplest job I've done; made up a mounting bracket to hold the reservoir to the RH silencer mounting next to the injection/ignition CPU, and ran about a metre of rubber tube along the sub-frame, past the battery, and then on down to the master cylinder.

Not only has this cured the problem, but filling/bleeding the system is now a piece of p**s should it be necessary - which it hasn't been for the last 3,000 miles!!!!!!

-- Senna 026 (, September 01, 2003.

Got pictures of the relocated reservior?

Like I said in an earlier post though, if all I had was the rear brake on this bike, I'd probably still slow down Fred Flintstone style. My rear brake has NEVER had the power to lock up the rear wheel. Maybe that will change. I really want to be able to use the rear brake on this bike at the track to help turn.

-- Andy Ruhl (, September 01, 2003.

Even when you first start riding the bike before it heats up, there is very little back break. They me at cagiva in PA that there is no problem, just an adjustment, and I should take it to the dealer, and have them adjust it. Don't think so. Pretty sad on their part. How do they expect to stay in business with their service and parts availability? H-ll you can't even get simple well nuts from anyone that are 4mm for the bike.

-- Tony Montana (, September 05, 2003.

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