Back to the brakes again...

31st July 2008, 15:23

Chaps,

As many of you might know, I've had issue with my braking for a while now, but I've noticed something which might be useful. I took the car out for a 10 minute spin, and I was really hard on the brakes, and every time, without fail, the car pulled to the left as it dug in and the weight was transfering forward. Anyway, when I stopped the car and inspected the brakes, both rear discs were cold to touch, not even warm, yet the front discs were untochable as they were so hot, even the wheels were hot... I know the rear discs are thinner, so they could cool down quicker, but don't you think they should have at least had some heat to them? If the rears are not working properly, or as strongly as they should, then under heavy braking, the rear of the car would be driving, causing issues which I'm getting. What do you think?

31st July 2008, 15:25

I would have thought the rear discs would be warm atleast..Also if only the front is working then yeah it will unsettle the car quite abit and may cause the pulling to one side..

31st July 2008, 15:30

Not sure what kinda setup you got but on my brothers saxo we tried adjusting the bias valve after it was lowered and it snapped, all the braking force was at the front. Have you checked yours over?

31st July 2008, 15:39

any mot place will be able to test whether the rear brakes are working correctly.

Round silverstone race circuit one of my rear calipers started leaking on one side. The car would give a massive twitch each time I braked heavily.

31st July 2008, 16:06

Quote:

Originally Posted by notime2chill

Not sure what kinda setup you got but on my brothers saxo we tried adjusting the bias valve after it was lowered and it snapped, all the braking force was at the front. Have you checked yours over?

I have the later model of 106 which doesn't have a manual adjustment unfortunately.

31st July 2008, 16:07

check the bias valve in that case

EDIT just seen your last comment. In that case something in the ecu or whatever controls the bias on the ghey 3 plugs has fucked up

31st July 2008, 16:07

Quote:

Originally Posted by KamRacing

any mot place will be able to test whether the rear brakes are working correctly.

Round silverstone race circuit one of my rear calipers started leaking on one side. The car would give a massive twitch each time I braked heavily.

I took it to one about 6 months ago, and they said the left / right braking force was perfect. I'm not sure how exactly they managed to test the rear brakes though...

31st July 2008, 16:08

Quote:

Originally Posted by jpsaxo

check the bias valve in that case

If only I had one...

31st July 2008, 16:09

Quote:

Originally Posted by jpsaxo

check the bias valve in that case

EDIT just seen your last comment. In that case something in the ecu or whatever controls the bias on the ghey 3 plugs has fucked up

Or it could be that putting bigger brakes on the front has caused an inbalance, or even something else.

31st July 2008, 16:16

the fronts do about 75% of the braking, the rears do very little. Its not unusual for the rear brakes to be cold or cooler.

31st July 2008, 16:16

tryed re-bleeding them ???

31st July 2008, 16:23

How low is your car???

31st July 2008, 16:28

Quote:

Originally Posted by Toad

I have the later model of 106 which doesn't have a manual adjustment unfortunately.

Thats weird, i have a 51 reg saxo and my bros is 03 reg.

1st August 2008, 20:33

Quote:

Originally Posted by Andy72

the fronts do about 75% of the braking, the rears do very little. Its not unusual for the rear brakes to be cold or cooler.

Fair enough.

1st August 2008, 20:33

Quote:

Originally Posted by Predator_VTR

tryed re-bleeding them ???

They've been bled many, many times.

1st August 2008, 20:34

Quote:

Originally Posted by KamRacing

How low is your car???

About 30mm lower at the front, and about 40mm lower at the rear.

2nd August 2008, 10:47

Quote:

Originally Posted by Toad

Or it could be that putting bigger brakes on the front has caused an inbalance, or even something else.

So have many other people, and havent had any issues. Rewire to single plug and install a bias valve ftw

4th August 2008, 15:26

Quote:

Originally Posted by jpsaxo

So have many other people, and havent had any issues. Rewire to single plug and install a bias valve ftw

Good idea about the bias valve. Do you know anyone / company fairly apt for such a job?

4th August 2008, 17:03

if its not the brakes themselves then it almost sounds oddily like bumpsteer, though you are not running that low. What suspension do you have? If you are running bilsteins are you running them with bumpstops? I just ask as all yellow bilstein shocks have internal bumpstops and any additional ones would shorten the damper travel.

4th August 2008, 17:18

Quote:

Originally Posted by KamRacing

if its not the brakes themselves then it almost sounds oddily like bumpsteer, though you are not running that low. What suspension do you have? If you are running bilsteins are you running them with bumpstops? I just ask as all yellow bilstein shocks have internal bumpstops and any additional ones would shorten the damper travel.

I'm using a Koni sports suspension kit. All the mounts and stops are standard.

I was driving down a fairly steep hill the other day, and there was no traffic anywhere, so I thought I give the brakes a good testing. When I brake firmly, but not too hard, the car seems fine, it slows down fairly well, and nice and evenly. But if I apply more pressure to the brake pedal, so you really get the brakes to bite hard, the car seems to go into an immediate slide to the left. It's quite scary, and you have to let off the brakes for fear of having an accident. I tried this hard braking 3 times in a row down the hill, each time the same left sliding movement. I'm fairly sure the road camber was even as well.

12th August 2008, 20:04

Quote:

Originally Posted by Toad

Chaps,

As many of you might know, I've had issue with my braking for a while now, but I've noticed something which might be useful. I took the car out for a 10 minute spin, and I was really hard on the brakes, and every time, without fail, the car pulled to the left as it dug in and the weight was transfering forward. Anyway, when I stopped the car and inspected the brakes, both rear discs were cold to touch, not even warm, yet the front discs were untochable as they were so hot, even the wheels were hot... I know the rear discs are thinner, so they could cool down quicker, but don't you think they should have at least had some heat to them? If the rears are not working properly, or as strongly as they should, then under heavy braking, the rear of the car would be driving, causing issues which I'm getting. What do you think?

I've got gti-6 brakes. Standard rears. MK2 vts ie no bias valve or whatever, also lowered around 50mm. Just driving at 30 through town and parking up my rear discs are pretty much to hot to touch after a second or two of touching. After heavy braking you can't touch them at all. For yours to be cold seems very odd! Only difference is you've got no weight in the back. I was told when my rear discs were low that how many miles they lasted would also depend on how much weight was in the back (MOT).

13th August 2008, 08:51

Quote:

Originally Posted by bytor

I've got gti-6 brakes. Standard rears. MK2 vts ie no bias valve or whatever, also lowered around 50mm. Just driving at 30 through town and parking up my rear discs are pretty much to hot to touch after a second or two of touching. After heavy braking you can't touch them at all. For yours to be cold seems very odd! Only difference is you've got no weight in the back. I was told when my rear discs were low that how many miles they lasted would also depend on how much weight was in the back (MOT).

Thanks for the info. That's interesting, as it does confirm my thoughts about not getting enough braking at the rear... It makes sense, as the car feels really skittish under heavy braking, which could effectively be the rear steering the car, as there's not enough braking in that department. I'm looking into getting a bias valve fitted.

13th August 2008, 10:45

I don't know much about this but you could put a load of weight in the back and go for a drive. If the rears are warm then, alteast you know its because theres no weight in the back and nothing wrong with the brakes, assuming they warm up that is.

13th August 2008, 11:09

Quote:

Originally Posted by bytor

I don't know much about this but you could put a load of weight in the back and go for a drive. If the rears are warm then, alteast you know its because theres no weight in the back and nothing wrong with the brakes, assuming they warm up that is.

There are no sensors to detect how much load is at the rear, so it won't make any difference to the braking force applied. I think the garage you took your car to are confused with the older model which has an adjustable valve on the rear axle. The ride height of the rear, changes the valve / spring position, and this adjusts the rear braking force.

13th August 2008, 11:09

Quote:

Originally Posted by bytor

I've got gti-6 brakes. Standard rears. MK2 vts ie no bias valve or whatever, also lowered around 50mm. Just driving at 30 through town and parking up my rear discs are pretty much to hot to touch after a second or two of touching. After heavy braking you can't touch them at all. For yours to be cold seems very odd! Only difference is you've got no weight in the back. I was told when my rear discs were low that how many miles they lasted would also depend on how much weight was in the back (MOT).

the 3 plug cars do have a bias valve, but its electronic. it uses EBD.

13th August 2008, 11:14

Yeh, i was just implying i have the same as Toad, not a valve you can simply adjust.

14th August 2008, 08:58

Defo something fooked with my brakes / ABS. This has happened a couple of times now, and happened yesterday: While applying the brakes normally / gently, an alarm buzzer sounds goes off from my ABS area, and the brake pedal goes stiff and then vibrates for about 3 seconds.

While it vibrates, the car seems to pull left a bit... Hmmmmmmm.

I think I'm going to get the ABS unit completely removed!

14th August 2008, 09:19

i had same problems as you toad, just d/c'd the abs sensors etc.

14th August 2008, 10:11

I think there may a bigger problem with the actual ABS unit, in the way it deals with the braking when it's functioning.

14th August 2008, 10:36

You need the ABS for the MOT Toad, so don't go doing something you can't undo for the test.

On a plus side, the brakes are a lot better without the abs, the pedal is harder and you have a lot more feel than you do with abs working.

14th August 2008, 10:47

Quote:

Originally Posted by bytor

You need the ABS for the MOT Toad, so don't go doing something you can't undo for the test.

On a plus side, the brakes are a lot better without the abs, the pedal is harder and you have a lot more feel than you do with abs working.

Nah, don't need abs for an MOT. If I had ABS and the system was faulty, then there would be an issue. But as I won't have an ABS system, there's no issue.

14th August 2008, 10:59

You may have a point!

14th August 2008, 11:04

Quote:

Originally Posted by bytor

You may have a point!

I would have thought the light on the dash will go out when you remove the system too, so an MOT tester would not even realise there wasn't any ABS.

14th August 2008, 12:41

mine passed mot with abs sensors disconnected and abs light on.

14th August 2008, 13:16

Quote:

Originally Posted by williamsvts

mine passed mot with abs sensors disconnected and abs light on.

Nice to know.

But I think you may have gotten a little lucky there.

14th August 2008, 15:55

Quote:

Originally Posted by Toad

I would have thought the light on the dash will go out when you remove the system too, so an MOT tester would not even realise there wasn't any ABS.

Problem is, they are supposed to check for the abs light as if its working it will flash sometime during startup, and must go out within a certain time from when the engine is started.

Whether it means if you have abs and it doesnt work then you fail, or your car *had* abs from the factory but it has been removed, so its not not working effectively, its simply not there so it passes?

The mot test on abs changed recently and abs now has to be working for it to pass.

14th August 2008, 16:03

Quote:

Originally Posted by Toad

Nice to know.

But I think you may have gotten a little lucky there.

wasnt really luck, was more like 1 of my best mates was the tester

18th August 2008, 10:15

Quote:

Originally Posted by bytor

Problem is, they are supposed to check for the abs light as if its working it will flash sometime during startup, and must go out within a certain time from when the engine is started.

Whether it means if you have abs and it doesnt work then you fail, or your car *had* abs from the factory but it has been removed, so its not not working effectively, its simply not there so it passes?

The mot test on abs changed recently and abs now has to be working for it to pass.

I would be surprised if there was a specific rule which states that if a car came out of the factory with ABS, it must still have the ABS system installed.

18th August 2008, 10:16

Quote:

Originally Posted by williamsvts

wasnt really luck, was more like 1 of my best mates was the tester

Does your mate do mobile work?

14th September 2008, 21:39

Yes but we took the abs fus'es out so it wasn't working full stop. i still reckon its a damper failiure mate. you said you have had the brakes tested countless times. but the only way is to start replacing parts as funds come availible. i take it you have decided to keep the car then

16th September 2008, 12:52

Yeah, still got her.

I think it's the calipers or the ABS system myself. I was doing about 5mph going into my driveway the other day, and just for interest, I slammed the brakes has hard as I could, and the car just jumped sideways to the left...

16th September 2008, 13:40

You sure your suspension is ok?

Wishbones could be shot, causing the wheel to pull backwards under heavy braking and effectively steering the car.

If the pads and discs are ok all round i find it hard to think there is uneven braking distribution.

16th September 2008, 14:44

Quote:

Originally Posted by ryhornvtr

You sure your suspension is ok?

Wishbones could be shot, causing the wheel to pull backwards under heavy braking and effectively steering the car.

If the pads and discs are ok all round i find it hard to think there is uneven braking distribution.

In theory, that's absolutely right. But I've had measurements taken and all shows up as being gravy.

16th September 2008, 15:43

Have you checked the calipers for the piston on the calipers being stiff nearly seizing, that could be your problem when it comes to braking really hard and pulling to the left!

And the brake bias problem can be fixed by peugeot!

16th September 2008, 15:51

Calipers have been checked, it was the first thing I did. The bias is apparently correct, a RR has proven this. Odd thing is though, if you brake firmly, but not too hard, it's absolutely fine. It's only when you brake really hard that it all goes tits up.