LM2 linked brake bleeding

The front left caliper has seized up and I no longer have 3 brakes on the LM2. Friends have been trying persuade me to de-link them but I actually like the system when it is working so want to retain it. I will be pulling the caliper to rebuild it shortly but before I disconnect the hydraulics I wondered how much of a headache it is going to be bleeding the system when I put it back together as I have never done a linked system?

Bike is a 1980 LM2 with standard Brembo calipers, cast iron discs and standard M/C’s but has had the lines changed before I got it.

Bleeding linked brakes is not really any different to bleeding normal systems. Don’t forget, the two disks on the front wheel of other bikes are linked, so the Guzzi system is not that weird.
Having said that; when I replaced the old hoses on my bike with braided hoses it took me forever to get the system working. I eventually found that one of the bolts on the differential valve was not 100% tight. Just the tiniest leak of oil gave it away.

I had no problem filling and bleeding my Spada, although other people seem to struggle. I cracked off the union at the master cylinder first to prime it, then bled at the proportioning valve, then the 2 calipers. Did both calipers a couple of times to make sure the last air was out.

What he said. If “impossible”, often indicates there’s a problem as exampled above. First tho ensure all the bleed nipples can be opened, that’s another can of worms if you break one or more off. :open_mouth:

And your ‘friends’ need to be put against a wall.

Thanks for the advice one and all. I’ll maybe not put my friends ‘against a wall’ but I will out brake them when I get this sorted! I will remove and rebuild both front left and rear calipers and start there

A couple of things I would add, Get a bleed tube, it makes the job so much easier. Local car factors do the orange tubes with a bung in the end and a split in the side. It acts like a one way valve. Saves the faff of open, squeeze, close, release and repeat for a hunderd times
Secondly, try lifting up the font caliper to avoid fighting gravity in the line down the fork leg. Put a bit of quarter ply in between the pads to keep them in place.
Once you have it all done, pump the pedal up and down plenty to get the pistons and seals seated.