406 Master Cylinder Causes Brake Binding

[Doof 11]

I've just put a 406 master cylinder with 23 stamped on the bottom onto my car and went for a drive but it seems the brakes are binding. I've read lots of posts by people using this so can't figure out why mine is binding, it's so frustrating that everyone else seems to get on fine with it but mine binds.

 

To clarify, it was definitely all 4 brakes binding, they were all red hot when i got back from a 2 mile drive.

 

I can't adjust the pushrod (just had a go and molegrips just won't hold it) so i need a master cylinder that will work properly...can i get any others that have a slightly shorter actuator?

 

Thanks,

 

Lewis

[Toddy 7]

Lewis

 

I use a 406 23mm 4 outlet MC and the pushrod was easy to adjust, sounds like you may need to find a way to screw the pushrod inwards or source a new servo.

 

The brakes have binded due to the heat expanding the discs etc, M@tt had the same problem from memory, be worth searching his posts.

 

I am presume that you have no slack in the brake pedal even when the brakes are cold.

Edited July 31, 2010 by Toddy

[Doof 11]

Can't remember now, it was actually a few weeks ago now. I've taken the master cylinder off until i can do something about it.

 

Can you explain how you adjusted the servo? Theres a nut and a funny star shaped bit but i'm not sure what is meant to turn?

[marksorrento205 80]

Mine did the same when I fitted the 406 m/c. I fitted it at the same time I fitted my 6 engine so I swapped lots of things to rule it out inc the servo. I kind of stopped doing it but every now and then (completely random and not often) it does it again. However when I pump the pedal (which there is no movement when it happens) a few times they release and I get the bit of travel back before the brakes come on?

To adjust the rod get someone to push the pedal down whilst you do it (just incase you are not) as it helps a lot because the pushrod pops out into view

Edited July 31, 2010 by marksorrento205

[Toddy 7]

Can't remember now, it was actually a few weeks ago now. I've taken the master cylinder off until i can do something about it.

 

Can you explain how you adjusted the servo? Theres a nut and a funny star shaped bit but i'm not sure what is meant to turn?

 

 

There is a locking nut and a domed nut on the end of the push rod, when you look into the servo from the front, you want to loosen this off then screw in the pushrod to allow some free play when the brake pedal is fitted, lets say 15mm on the pedal before the pushrod touches the MC.

[Doof 11]

I had a go adjusting the pushrod and just don't believe anyone has managed to do it. It's just not possible with the rod still in the servo. You can't get two pairs of molegrips in there and the shaft just spins.

 

I read a post by M@tt saying he got the rod out but after 10 minutes I've deemed that impossible too. He must have a different servo to me because mine will not come out.

 

Basically I'm just going to give up and go back to a 205 1.6 servo.

[Rippthrough 98]

Pair of bent needle nosed pliars and a socket.

Sorted.

[Doof 11]

Ok so it is actually possible! Basically molegrip the living s*it out of the locking collar on the shaft and use a socket to turn the nut. I still butchered the collar but it worked!

 

I also found i had to undo it a few turns first to get it freed up then i could wind it back in slowly. I ended up doing about 6 full turns and will have to see how the brakes are now. It's probably about 3-4mm shorter now.

 

In terms of the amount of movement in the pedal. I got someone to hold the master cylinder against the servo and pushing the pedal with my hand i could feel a tiny bit of travel before it made contact with the rod. After bolting it up fully that travel disappeared so it's actually still in contact, but hopefully only by the smallest amount. I'll be sure to post back how they feel once I've bled all the brakes and I've been for a good drive.

 

Thanks for kicking me up the arse and making me try again guys. I nearly gave up and went for the old MC.

Edited August 2, 2010 by Doof