Brake Problems - Again!

[Scorpion-gb]

Hi, sorry to raise an old topic (I have searched the forum and read many of the threads).

Just changed front and rear pads on the Rav, didn't encounter any problems, pistons slid back into the calipers okay, no leaks, nothing jammed etc. Tried the brakes and the pedal slowy sank to the floor. Bled the brakes, 3 times, no air coming out of bleed nipples, used 1/2 litre of Dot 4 brake fluid so it's just about flushed the system!

Still have the same problem, read this has happened to quite a few people but can't see a definitive answer as to why. Read a lot of replies from people who said their Rav had always done this, mine never did before the new pads. I can't see how the master or slave cylinders could have been damaged and I've read that a few people changed the master cylinder and the fault remained. Brake fluid reservoir level never alters and I've felt the discs after ging for a 5 mile drive, they're all warm / hot so the pads are in contact with the discs.

Hopefully someone will be able to point me in the right direction, although reading the other posts no-one has ever reposted to say the problem was fixed or how it was fixed.

Any help would be greatly appreciated.

Thanks. Jim.

[anchorman]

Not this old cookie again.

If you pump the pedal with the engine off and it goes rock hard you are OK.

I can assure you that mine goes to the floor with the engine running.

[igormus]

Hello Jim

Check with an actuator vacuum pipe connected with suction manifold --whether it is not blocked partly or so ??

Whether pads repeat the disc shape andd degreased well ?

cheers / Igor

[Scorpion-gb]

Thanks for the replies. Anchorman like I said in my first post the brakes were not like this before, the brake pedal did not slowly sink to the floor before I changed the pads. I'd be crapping carrots if I had to drive a car with brakes this inefficient!

I've been doing a bit more searching and it may be that I have damaged the master cylinder seals by forcing the brake fluid back through the system when I compressed the calliper pistons back in. Don't know why it should happen this time as that's how I've always done it with previous cars?

Looks like my only option is to buy a new master cylinder (ouch) and hope this cures the problem. There's no way I would drive the car at the minute with brakes this poor.

[Davrav]

What happens if you stamp on the brake pedal when moving forward?

[Parts-King]

I doubt you have a problem. This is a phono phononom, condition due to the ABS and VSC where there is a lot of travel in the pedal. IF this is the case, it is perfectly normal

The thing to do is: With the engine OFF pump the brake pedal several times to remove any vacuum. Then still with the engine off, press and hold the pedal down hard. Does it creep? if NO, then you are experiencing the condition and this is perfectly normal. Does the pedal creep? If YES then you have a faulty master cylinder (or leak elsewhere)

This situation crops up time after time, Toyota and VOSA have written it up many times so that cars do not fail the MOT for a problem that does not exist

Kingo

[anchorman]

Does it creep down with the engine off???

[Scorpion-gb]

Does it creep down with the engine off???

No mate, it doesn't. I've think I've read nearly every write up there is on this subject and it seems I may be over reacting to the brake 'problem'.

I took the Rav for it's retest yesterday thinking, 'there's no way it'll pass with the brakes like that', and it sailed through! My wife has driven it and she says she can't feel any difference in the braking. Perhaps it's just me but they still don't feel like they did before I changed the pads.

Oh well if it's good enough for the MOT tester (and the missus) it's good enough for me. Thanks to everyone for all your advice.

[Big Kev]

Does it creep down with the engine off???

No mate, it doesn't. I've think I've read nearly every write up there is on this subject and it seems I may be over reacting to the brake 'problem'.

I took the Rav for it's retest yesterday thinking, 'there's no way it'll pass with the brakes like that', and it sailed through! My wife has driven it and she says she can't feel any difference in the braking. Perhaps it's just me but they still don't feel like they did before I changed the pads.

Oh well if it's good enough for the MOT tester (and the missus) it's good enough for me. Thanks to everyone for all your advice.

For what it's wurff, Jamesy, I picked up a Rav off eBay for a neighbour a few months back. She had never driven it, and was used to a nearly new hire car's overbraked system. She thought the Rav's brakes were bad....until she had driven it for a while.(2004 automatic 5 door.) She now believes me it is the norm.....they really do stop ye, regardless od feel / perception.

Big Kev

[Jamesbelfast]

On cars with ABS systems it is recommended to open the bleed nipple when retracting pistons - the ABS distribution unit doesn't always take kindly to having fluid forced in the wrong direction.

I have came across this problem 3 times over the past 5 years or so. Two of the three resolved themselves after bleeding and the brakes were bedded in - the other (Honda) required a replacement ABS unit.

It should also be remembered that on cars with disc operated handbrakes it is essential to release the handbrake adjustment before retracting the caliper pistons.

[kenny7964]

i have had this strange phenome### issue on several Diesel cars BMW, Golf, Discovery to name some. it always clears up within a few days, spoke to a friend who runs a garage about it and he informed me it is a comon issue to many makes but mainly Diesel cars.

[kencat]

it will bed in in a few 100 miles the pads r siting on the riges worn into the disc ! as you r pressing on the pedal thay r comprssing in to the groves i had this problem years ago on a shogun after a week it went ! if not change the discs 2 !