front brakes binding after new master cylinder

strassenbaum gurgled happily, sounding much like they were saying:

ABS on it?

If it is, then gawd knows. If not, then a duff master is the most likely cause. Just because it's new, doesn't mean it's good.

No ABS and I don't know if the master cylinder is new - looks more like recon to me.

Faulty replacement master cylinder , abs system not reset correctly if fitted , incorrect fluid / contaminated fluid used

Take it back to the garage who fitted the new cylinder

Only time I've had this was when the master cylinder was overfilled.

Chris

Taking the top off did not release the pressure so although it is pretty full, I don't think it can be that.

No, if it was pressurised you would be in trouble!

It still shouldn't be filled above the Max line though, and it's the easiest of your options to try.

Chris

OK - will try that, although if it is overfilling, it looks like the garage is also of the overfilling school as I didn't fill it until after the problem started. To be honest, I never even look for a max line - just put in what seems right to me. I've never thought of it as a potential problem before - so thanks.

when the brakes are stuck on, try undoing the bolts that hold the master cylinder to the servo, if the brakes release then you know that the cylinder is being slightly pushed all the time, which will stop fluid returning easily, it will be worse when the system is hot. The brake pedal/linkage may be pushing the cylinder slightly. The rod that pushes the master cylinder may be adjustable. If so then back it off a little. best advice though is to just take it back and let the supplier fix it.

strassenbaum gurgled happily, sounding much like they were saying:

"new-to-you".

If it's a recon, it's even more likely. I had a pair of recon rear calipers a few months back. One went straight back - stripped thread on the handbrake adjuster.

had the same sort of thoughts.

Could be they didn't bleed the system enough and adjusted the rod to get a peddle (pressure). hence blocking the return hole in the master cylinder.

When the air has settled out after a day or two hence the results.

I phoned the garage who agreed to take it back and replace - then phoned me back a bit later with the info that the supplier of the (confirmed recon) unit states they've had a few faulty ones - and so he has ordered a genuine part and intend to supply and fit it free. So this sounds good news.

He did say there is no adjustment.

good result

Very. The garage seems decent. If the end result is good, it may be worth naming them.

strassenbaum used his keyboard to write :

Therefor it has to be a fault with the new master cylinder.

There has to be adjustment. Usually on the servo actuating rod, but It could also be achieved by shimming. Not normally necessary, the only one I ever had to adjust when changing a master cyl was one which had too much clearance and gave a long pedal movement before operating the brakes ie the opposite of your problem. Half a turn on the nut fixed it. This is probably what your garage are going to do.

Steve

[...]

Why?

I haven't seen an adjustable link to a brake master cylinder in years. Things are manufactured to just fit these days. Even the accelerator cable on my Focus has no adjustment.

Chris

Because if not you get the problem the OP has. I'm not familiar with the seicento, but if there isn't some means of ensuring the correct clearance I'll eat my toolbox. Steve

I've browsed several threads on brakes here:

and looked at illustrations of Seicento master cylinders online, and from what I can see, you might need to sharpen your false teeth!

Chris