Some help please (brakes related)

[Andrade]

Yesterday the brakes got jammed while driving, I pulled to the side of the road and the brake pedal was rock solid. I jacked the car from both front and back, and both front and rear wheels couldn't turn, so it was like the brake pedal was being pressed.

 

I disconnected the servo vacuum as I thought there's something wrong there, gave it a few knocks while a friend was inside pressing and releasing the pedal but it was still jammed.

 

At the end I took off a front wheel, opened a bit the bleeder to let some hydraulic out and it did the trick. The car is driving normally now but i am assuming the fault is still there and I just hid it.

 

Any ideas what it could be?

[sambo]

was it both calipers stuck or just 1?

 

Could be the piston sticking? but unlikely to be both sides simultaneously?

[Andrade]

was it both calipers stuck or just 1?

 

Could be the piston sticking? but unlikely to be both sides simultaneously?

 

Both front and rear brakes were applied (and the handbrake was down). I would think it's something central like the master cylinder, however if that got stuck it wouldn't work normally after releasing some hydraulic?

 

Perhaps someone injected more hydraulic into the lines when i wasn't looking lol

 

The things i know are a bit tatty are the flexible brake lines that connect to the struts, but i can't see how these will make the pedal stiffer?

[Andrade]

Ok, so i have changed the master cylinder rubbers however it was still getting stuck so i decided to buy a new one, and it's now in place.

 

The problem is that the brake pedal is now really soft (with the engine on) like theres lots of air trapped in the lines. I bled the front and rear 3 times and no air is coming out. I have changed the flexible brake pipes front and rear too while i was at it.

 

Any ideas what it could be? the rear self adjusting shoes mechanism is working fine, the master cylinder was topped up to the full when bleeding and no air went in. there seem to be no leaks anywhere..

[over_head_cam]

If the pedal goes hard when the engine is off and soft when the engine is running then I would say that is normal. As long as you have some movement left for the pedal once the brakes are on (e.g. space under the pedal when you put it down hard) then it should be fine

[Andrade]

If the pedal goes hard when the engine is off and soft when the engine is running then I would say that is normal. As long as you have some movement left for the pedal once the brakes are on (e.g. space under the pedal when you put it down hard) then it should be fine

 

thing is that to have some brakes i have to push the pedal as far as it goes, and it reacts very strangely. usually you'd feel the pressure and you can apply it accordingly, but as soon as i start feeling pressure its like you stepped on it as hard as you could. i keept slamming into the seatbelt

[livewire7116]

are you running any type of servo?

[Andrade]

are you running any type of servo?

 

yes standard capri one, to be honest i have my doubts about it, but i had ran the capri with it disconnected before and brakes were fine only a bit stiffer. now with it disconnected the pedal is stiff but brakes dont start working until i push the pedal to the floor :S

[Andrade]

just came across this article:

 

http://autorepair.about.com/od/troubles ... brakes.htm

 

Brake Pedal Goes Too Far Down to Stop. If you step on the brake pedal and it feels like it's going too far down before you start to slow, you might have the following problems:

 

Low Brake Fluid Level: Check your brake fluid. If it's low, top it off to the mark on the side of the reservoir.

Contaminated Brake Fluid: Even though your brakes operate in a closed system, contaminants can still work there way into the works. Air can enter the system through the smallest hole, and you can end up with water in the system from condensation and other means. There's not really any way to check for this, but bleeding your brakes will remove the bad stuff and replace it with new fluid.

Worn Brake Pads: Your brakes should never wear low enough to cause your brake pedal to feel low, they'll scream at you before then. But if they do get very low, you might have this problem. Replace your brake pads as soon as possible. Of course, this can be avoided with regular brake inspection.

Bad Brake Power Boost Unit Finally, if your brake booster goes bad you'll have low brake pedal issues. Most brake boosters are vacuum controlled, so a special vacuum measurement device that connects to the brake booster is needed to check it. If it's bad, you'll have to replace the boost unit.

 

and also this one

 

http://wiki.answers.com/Q/What_is_the_c ... d_and_bled

 

If the brakes work fine, but just seems like the pedal is too soft...or even too touchy, look at the brake booster, vacuum lines to the booster, and the vacuum connections on the booster. A bad booster can make the brakes feel too touchy or soft. These are just ideas from things I've run into on my own 64.

 

Sound like the booster is gone, I have new master cylinder, new braided flexi lines, bled the system three times, new pads and shoes adjusters are working fine (got them checked by a local mechanic friend too to confirm)

 

The booster does make an air noise when I press the pedal but it was always like that even when the brakes were functioning normally. When it does the air noise the engine revs more.

[JP.]

In my experiance.......if the servo is gone the pedal is harder en de engine stops running when pressing the brakes on idle.

Normal if a servo is leaking internaly it won't assist like pressing the brakes with the engine not running.

 

Next one.......did you replace the Capri type master with a new ATE one ?????

Cause ATE stopped making them more than 20 years ago. All you can get now is old stock. Internal rubbers are gone now as they won't last by sitting 20 or so years on a shelf.

Had lots of the same issues you have with those so called new ATE masters in Holland so we contacted ATE in Germany which insured us the stopped making them in the mid '80s.

 

If you have a ATE master best thing is to put a rebuild kit in it cause those aftermarked rebuildkits ar most of the times new made.

 

Next an ATE related tip. 20mm and 22mm ATE masters are not intechangeble on the servo. Putting a Capri 2.8i 22mm ATE master on a Capri 1600/2000 ATE servo will get the brakes on even when not pressing the pedal as the internals have not the same dimensions to match.

[escort21]

Brake master cylinder is to large

[Andrade]

Brake master cylinder is to large

 

We measured the bore of the master cylinder and it matches the old one. Also both old and new master cylinder have a red plastic ring around them.

[Andrade]

In my experiance.......if the servo is gone the pedal is harder en de engine stops running when pressing the brakes on idle.

Normal if a servo is leaking internaly it won't assist like pressing the brakes with the engine not running.

 

Next one.......did you replace the Capri type master with a new ATE one ?????

Cause ATE stopped making them more than 20 years ago. All you can get now is old stock. Internal rubbers are gone now as they won't last by sitting 20 or so years on a shelf.

Had lots of the same issues you have with those so called new ATE masters in Holland so we contacted ATE in Germany which insured us the stopped making them in the mid '80s.

 

If you have a ATE master best thing is to put a rebuild kit in it cause those aftermarked rebuildkits ar most of the times new made.

 

Next an ATE related tip. 20mm and 22mm ATE masters are not intechangeble on the servo. Putting a Capri 2.8i 22mm ATE master on a Capri 1600/2000 ATE servo will get the brakes on even when not pressing the pedal as the internals have not the same dimensions to match.

 

Not sure what the master cylinder is, will have a poke this evening. Thanks for the guide!

[Yeomans22]

i had this kinda thing on my capri when i changed the master cylinder a couple of months ago, it turned out the master cylinder was full of air, so loosen each pipe 1 at a time off the cylinder slightly and press the pedal the air will be removed from the cylinder then bleed the brakes as normal, worked fr me, brakes are perfect now.

[Beakster]

How are you bleeding the brakes? I put a new master cylinder on one of my Capris last year and had the same issue. I'd bled about 2 litres of fluid through the system using a Gunson EZbleed but the pedal was still going to the floor. Bled them manually stamping really hard on the pedal and a load more air came out that must have been trapped somewhere and that sorted it. I think using air pressure from a tire just isn't enough to clean some airlocks.

 

Also worth making sure the rubbers in the new MC are good if they are actually very old. And check the rod length on the back of the new MC is the same as the old one.

[Andrade]

Have been running the car with the vacuum off the master cylinder (put a bolt in the pipe). Pedal is a bit stiff of course but it works and brakes respond as soon as I start applying pressure, so I am eliminating airlocks from the equation. Will try to source a new servo unit from a local store first, if I cant find one I'll go for a second hand one.