brakes locking on

[normanpitkin]

hi

i just had my brakes adjusted and got a nice hard pedal ,however on driving the brakes gradually locked on and no the car is immovable ,Has the mechanic tightened  the rod on the master cylinder too much ? How to rectify ,all the lines and pads are as new and the system is completely flushed with new fluid.

[joecoozie]

Sounds like the rod needs to be adjusted. If it is adjusted incorrectly it will not allow the fluid to come back into the master cylinder when you let up on the brakes.

You can probably release the brakes by opening a bleeder screw - just to get the car moving again

Also, you should have some pedal free-play travel before the brakes engage.

The pedal should not be "hard" all the time.

 

[plymouthcranbrook]

Make sure the hole in the master cylinder that allows pressure relief is open. Open the cap and gently push the pedal.  You should see a small fountain just behind the hole where the piston is. They often get blocked and need to be opened up with a small wire. A search will give more information.

[normanpitkin]

problem fixed ,it was the rod into the master cylinder was too far in!

[SteveR]

23 hours ago, normanpitkin said:

problem fixed ,it was the rod into the master cylinder was too far in!

I had that same problem. Simple adjustment and your good to go.

[normanpitkin]

now the brake pedal almost touches the floor before it bites!! My local garage has no experience of this ebrakes but my fading memory tells the cam on the back of each drum needs to be adjusted, until it drags ,then slacked off a little ,THEN the brakes bled/rod adjusted.

[kencombs]

First check the actual pedal free play.  It may now have the rod too short.  Then adjust shoe to drum clearance as you mentioned. 

[Sam Buchanan]

1 hour ago, normanpitkin said:

now the brake pedal almost touches the floor before it bites!! My local garage has no experience of this ebrakes but my fading memory tells the cam on the back of each drum needs to be adjusted, until it drags ,then slacked off a little ,THEN the brakes bled/rod adjusted.

 

From our Tech section of the forum:

 

https://p15-d24.com/page/p15d24/tech/brakes.html/

 

Read and reread until it makes sense. 

[SteveR]

2 hours ago, normanpitkin said:

now the brake pedal almost touches the floor before it bites!!

I have had this problem. 

First check your fluid level in the master cylinder. Top-up if necessary. You might want to pull your drums and see if there is any brake fluid that has gotten on the shoes. Look at the drum surface and see if it has glossed over. If so, rough up the surface using sandpaper for a temp fix. Make sure the seals are good and not leaking grease from the wheel bearings.

Replace drum, bearing and nut. Tighten nut to proper tension and install a new pin. Now adjust the eccentrics. You might want to bleed each wheel cylinder or at least check them.

The bleeding usually takes 2 people unless you have a bleeding kit. The above is not difficult and can easily be done by anyone.