355 Rear brakes seizing after a major and Master Cylinder Replace 97 f355 spider

I've not experienced this on a 355 but have on other cars. In my case it was the result of a new master spending an eternity on the shelf (or so I surmise) and the result is what you describe.

Not sure the abs unit could even influence this. If properly bled and adjusted I would still think this comes down to the master.

Experienced Ferrari techs may have a different opinion based on experience, just my opinion based on experience of others.

 

hard to guess what another shop might do right or wrong. Lets say everything is right then what about a WAG? Here is my WAG. Every major IMO should come with a brake system flush not just a reconnect and bleed. Why did master die when it was fine before major? Well often the master say has a 2 " stroke but in use over years your active stroke is say 1.5" so you got 1/2" of master that never gets wiped over by the seal. So sharp crap build up in there. Mechanic does a bleed and full strokes your pedal the whole 2". The sharp stuff violates the master and forces all the crap into your lines. Your master is now dead. So you have to replace or rebuild the master. If a bleed is done and not a full flush perhaps you got debris blocking the residual pressure valve so that the aft of the valve line pressure is higher than it should be thus activating the rear brakes especially with heat.

Solution flush the crap out of the lines and see if you get lucky to clear the valve. Sometimes you have to remove and replace or remove and clean the valve. A quick check of the valve might be to force the rear caliper pistons back into the caliper with the same force you use when you change the pads. If the force is higher suspect the valve or really FU'ed caliper piston seals. Action on the pedal should bring the pistons right back home against the pads and rotors.

It is also possible to have FU'ed piston in a caliper but if both sides are grabbing that is unlikely. Pushing pistons back into the caliper then moving them out with the pedal is a good thing. Upon release the rotor should turn with just a few lbs of force. sometimes you get some dragging and sometimes you get free spinning that's car dependent. But rotors should turn without any pedal pressure. If you can't move the rotor easily it is in the piston seals or the residual valve holding too much pressure. You can prove the valve by cracking the connection like when you bleed brakes and if the connection leaks out some fluid and the rotor now turns you got your answer.

Hope that gives you some ideas.

 

You can confirm that indeed both left and right rear brakes are sticking on? Interestingly, the park brake adjustment also is disturbed during the engine oit major..

 

I don't entirely disagree with FBB, but the odds of crap in the MC or lines blocking the lines to the extent that they would hold enough pressure to lock the brakes is a stretch. My opinion is that the shop eff'ed it up; the shop is responsible to fix it. What I don't like in the OP's post is the "We determined...." If the shop told me it was probably the MC I'd be like, "If you replace it and it don't fix the brakes it's on your dime."

Are you sure they didn't get air in the ABS modulator when they replaced the MC? That requires a little more complex bleeding. Did they prime the MC before installing? Typically this needs to be done with dual/split braking systems.

 

How did they bleed the brakes initially? And was the master cylinder bled at that time?

 

Can you confirm whether it has the Teves system or the Bosch system?

 

Parking brake adjusted too tight? Seen that more times then I care to think of with old drum brakes .

 

That’s exactly what I was thinking and would definitely look into before I went any further with the actual brake system. The e brake could be dragging and when they heat up they expand and start to lock up. The first time it happened and he adjusted the MC rod it may not have actually done anything the ebrake just had a chance to cool off and let the wheels turn again... until you drove and heated them up again.

Maybe it’s wishful thinking but it’s something simple you could check before getting any deeper.

 

3 things happen to the rear brakes during a major.
The line is disconnected and capped.
The parking brake cable is disconnected
The brakes are bleed when finished.

It's gotta be related to those 3 things. Although now your mechanic has introduced a 4th item, the new master.

I wonder if it's possible he left whatever he capped the brake line with in the line when it was reconnected?

Parking brake seems reasonable. Have them totally loosen it for test drive purposes.

How is he bleeding it? Pump and crack?
Try a pressure bleeder.

 

Wow. Thats a new one for me.

 

I had this once on a different car when the master cylinder reservoir was overfilled. Quick check to take it out of the equation.

 

Im not buying it that explanation.
You said it happened after a few minutes of driving? So pushing the wheel out a tick over 1/2" caused the rear calipers which aren't even in contact with the bearings, to heat to the fluid over 600* and seize the brakes??
My vote is it was fixed with one of the other troubleshooting efforts and/or its a gremlin that will come back later.
I say drive it a few weeks and through the spacers on there again.

 

That makes absolutely no scene at all and I would say is very close to completely impossible. There’s just no way spacers could have the effect you were talking about. No, just no way.

 

I'm not buying it at all either
Only spacer deal I can think of is too long a bolt holding them on and when it gets hot the bolt expands, hits inboard locking them up, metal on metal sound

 

Yes, not buying it. My guess would be it could have been from incorrect bleeding of the ABS unit and the pressure relief valve for the rear brakes. Or maybe aliens. Pretty sure it was aliens now that I think about it.

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Spacers cannot cause that. You have a different problem.

 

Fail.

 

I think you can put them back in now.

 

If it was indeed the spacers, they would have had to have been heated up to the point of changing colors.

My bet is still on an improperly adjusted parking brake. By now, perhaps enough of the shoe material has been worn away that the issue 'self-corrected'.