92 2.2 weak BRAKES

[jaswasup]

Operational but very weak
I would hate to have to give em a hard push on as it seems the pedal will no harden up
I checked the front pads and rotos etc and all looks well
Loads of pad left
I had all the lines replaced in the spring and have noticed the difference beween my brakes capability and my wifes vehicle
I have heard of low vacuum on the booster or a valve in the system but not sure where to think i should look or test which component and wth what tool
All i want is to have great braking capabilities if a extreme condition called for it
I would say my brakes are at about 60 - 70 % operating value in my opinoin

[1996camry]

you might have air got inside your brakes line...you need to bleed all 4 brakes... and see if that fixed... if not, your brake boster could go bad... if brake boster go bad, your brake go down without resisitance to stop the car.

bleed 4 brakes to see if fixed, first.

[1996camry]

when you bleed, make sure you have fluid up to the mark (full) on your brake resorvoid before u bleed 4 brakes...this prevent from air get back in your brake lines when fluid is LOW.

[xtremeskier97]

When bleeding...start with the wheel furthest from the booster, which would be RR, to the closest. So order would be RR, RL, FR, FL. Make sure that the fluid level doesnt go low or you will have to start all over again.

Has the fluid ever been replaced? Wouldnt be a bad idea to replace it all since you will be bleeding the whole system anyway.

[1996camry]

lets us know if bleed your brakes would do the job (fixed)....

[Hajoca]

Check the master cylinder to see if it is leaking ( at piston seals)

[jaswasup]

Originally Posted by Hajoca

Check the master cylinder to see if it is leaking ( at piston seals)

Is this a visual check only ?
I will bleed the lines ths week end and do a system visual as i checked the reservoir today and fliud is down near to the sensor but the light on dash has not come on yet so perhaps there is a small leak aswell
I will further the investigation and advise on findings

Thanks

[Hajoca]

With car engine off, push the pedal down and hold, does it keep sinking, and repeat several times to see if that happens as you loose vacuum assist.

[1996camry]

if your brake reservoive goes down below the minimum mark or below the MAX mark on your reservoive, then i refill brake fluid (follow what brake fluid to put in your car...consult your car manual)...(the spec. what brake fluid should put in your car...look at the last pages for spec brake fluid....

if the reservoide brake fluid go down a lot, the air could get in your brake line...when you do the bleeding..check the brake cables for crack or demage... follow the above INSTRUCTION to bleed...you need 2 people to do this..
have the car turn OFF
have some in the car push the break down like you would try to stop the car ( try to several times) until the brake can't go down any more... Ask that person to hold the brake,
now you use 10mm wrench to loose the brake (should behind your brake drums or dis rotor)...you can tell...you need to take that cover rubber off before you loose the nut (10mm wrench)...when you loose the nut..ask the person hold the brake...and when the fluid go out....ask him to push the brake all the way down....now, you need to tight the nut back tight..and try 1 more time again...then tight back it tight..(you done one side now)...go to next one (bleed).

[daveart]

could be air but i would make shure your sliders are free and remove the inner shim on the pads if they look rotten,this will help,also adjust the rear brakes but shave the edges of the shoe linnings(top and bottom not the sides)this will prevent noise,

[jaswasup]

Do you mean GRIND the surface of the steel that goes into the clip ?
Or the pad lining itself ?

[daveart]

no i mean the shoe linnings itself,you say pads you have disc in the back also?if so to adjust that you need to take the rubber plug off the disc and rotate the hole till you see the sdjusting wheel(bottom of the system)turn it upwards till the wheel locks then back it up 2 turns ,do this to each side,and you dont have to shave the pads in this case,just lubb the slider good and make shur the rubber boot goes over and covers as water can get in and seize everything,

[marc780]

How about your calipers, how many miles on them - they could be sticking and weak and you'd never know it by looking at them.
This car is a 92 and plenty of miles on it nou doubt, do you know if or when the calipers were ever replaced? If you dont know its a safe bet they never have been replaced or even come apart. So i'd at least remove the calipers and take them apart for a cleaning and inspection. You need compressed air to carefully blow out the caliper piston (through the brake hose hole) but after that it is not too hard to take them apart.

You'd be looking for a scratched piston bore, very dirty piston bore, scuffing and other wear on the cAliper piston. Work the piston up and down in the bore, a sticky piston is bad of course. If you have any doubts about the calipers condition and you can afford it right now, i'd just change them out, at least the fronts.

Caliper rebuild kits are cheap but hard to find anymore - and usually a waste of time anyway; because if the caliper is worn badly enough to leak, the rebuild kit (usually just a couple of neoprene seals) is usually not going to do much good.

If you have rear drums, dont forget those either - maybe your return springs are weak (available in a hardware kit) or drum contact surface is worn or, brake cylinders are worn inside or very dirty. Like brake calipers, wheel cylinders dont have to leak to be worn out, a caliper/cylinder can be plenty worn inside and never show a leak.

Also dont forget, a rotor can look good on a cursory inspection, but actually be bad - unless it is smooth, has no wear ridges (the wear ridge on the outer edge of the rotor tells the tale of how much wear it has) - the rotor is suspect as worn rotors can also be a problem when diagnosing weak brakes.

[Kep]

Page BR-7 of the 1995 on-line manual gives 10 checks for a "Hard pedal but brake inefficient". You might want to go through those. One thing that you mentioned was the booster. From your description I can't really tell if your brakes feel spongy or hard. If you have a vaccuum leak or the booster mechanism is damaged you would experience a working brake but one that you really had to press down hard on.

There are two tests for the booster described on BR-9 of the 1995 Camry Manual:

BRAKE BOOSTER OPERATIONAL TEST
1. OPERATING CHECK
(a) Depress the brake pedal several times with the engine
off and check that there is no change in the pedal
reserve distance.
(b) Depress the brake pedal and start the engine. If the
pedal goes down slightly, operation is normal.

2. AIR TIGHTNESS CHECK
(a) Start the engine and stop it after 1 or 2 minutes.
Depress the brake pedal several times slowly. If the
pedal goes down farthest the 1 st time, but gradually
rises after the 2nd or 3rd time, the booster is air tight.
(b) Depress the brake pedal while the engine is running,
and stop the engine with the pedal depressed. If there
is no change in the pedal reverse travel after holding
the pedal for 30 seconds, the booster is air tight.

Hope this helps,
Kep