I use a 99 toyota camry. On 2nd January, i noticed the brake became stiff and was not pressing down to the end. The mechanic changed the master cylinder. I also noticed that one of the bolt holding the master to the servo was broken leaving only one bolt. Since i didnt have the money to change the servo, he welded a bolt to the body of the servo and tight the master with it. It has been okay since then but i noticed the problem occuring at intervals in the last 3 days, however, i have checked if the welded bolt is off and i found out it was still intact. Since i have changed the master cylinder a month ago, How come i'm having this problem? The brake is holding but it is not free. Infact it is not pressing down to the end. Experts , plz advice on wot i should do. Tanx

The mechanic must be a big time clown.

Please the problem is with the brake booster ( otherwise known as servo). Only two things in servo can cause this: the big vacuum seal/rubber in the booster if broken or the small plastic L-shape pipe where the vacuum hose from the cylinder head is attached to the brake booster.

First, check if the plastic L-shape thing on the booster is still ok. How do you do that? Pull out the plastic thing from the booster ( the peugeot one is very easy to pull out, i wouldnt know of Toyota), remove the vacuum hose from the plastic, blow air into the plastic with your mouth. The air is suppose to come out from the other side or opening. Turn to the other opening and blow in air, it should be blocked, that is, air shouldnt come out from the other end or opening, that is, only one side should pass air. The two openings shouldnt pass air, when you blow air in from both side. If the two sides pass air, replace the plastic thing, thats is the culprit. But if it works fine, then you need to open the brake booster and inspect the big seal/rubber inside. Its likely leaking air or broken. You may have to take it to a brake booster repairer open and replace the seal for you or possibly replace the entire booster if you cant find the seal.

Meanwhile, check to see if the vacuum hose is well attached on the brake booster and also on the cylinder head. Also pull out the hose, inspect the hose & blow air into hose to check if broken or leaking air.

If i may ask, its your brake system ABS?

Ikenna.

@ Ikenna,

Tanx so much. However, my confusion is that if it was the servo from the begining, why was it okay for 1 month since after the change of the master. Meanwhile, it also seems that the brake is also not releasing from the front wheels cos the car is failing to move except if u throttle. I checked my two front wheels and i found out it was excessively hot maybe because of the excessive friction. At some point everthing normalises , but later it goes bad again. Apart from the servo, is there any other thing that could make the brake to grip the tyres even after the pedal is released?

I think its ABS but i'm not very sure but i'll check.

Brake flexible hose failure can make a wheel to bind/seize. From your explanation, it appears the pinion of the front brake chamber in the master cylinder is intermittently not returning after depress. Since the 2 front brakes are binding, it shouldnt be the flexible hoses. Both cant just fail at the same time. The problem should be from the master cylinder. It needs to be rekitted.

But, if you are saying they did a welding job on the brake booster, the booster seal may also have failed. How could someone have done such a terrible job, without realising the effect of the welding job on the booster seal? It really baffles me!

Ikenna.