brakes (again) but this time with photos

[ferny]

Background;
Found a flexi house to be dead so replaced all four on the car with Goodrich Stainless Steel Braided ones. Now to me the peddle feels like it has too much free-play. I've taken some photos to illustrate what I'm feeling.



1 - This is when the peddle is at rest



2 - This is the first hint of "feel" in the peddle. A really tiny amount and you don't notice it when moving (I had to move my foot to the right a bit so I wasn't touching the clutch, same for all of the next ones)



3 - This is where the car will just about start to feel like the brakes are on but it's hardly slowly down so you have to push down harder



4 - This is the peddle all the way to the floor, it won't go any more. Just before this is around where I need to push the peddle for the car to slow down properly (in my view, and I tend to brake a little late)



Testing at around 30-40mph showed the car to stop dead straight and if you want the tyres will make that just about to skid noise. But to me it feels like there is too much free-play there. I've certainly no expert and this is the first time I've driven a car like this. It was also pointed out rather emphatically ( ;) ) that this was fine. But I'm not sure.

So, the floor is open. :)



I just tried to show this a bit better. In this one it doesn't look so bad, but I think the camera angle is the cause of that. Either way, you can sorta see the percentages between each stage, so it may help.

Short answer, is this about normal for my car? What should I be feeling and what should be happening?

[heraldcoupe]

There will always be a bit more travel in a disc brake setup than with drums all round, but you should have a very firm pedal with no more than 2-3 inches of travel. If the pedal comes close to hitting the floor, then there is something wrong. Check adjustment of the rear brakes. Front brakes will be self adjusting, though they are affected by any play in the wheel bearings.
Did you carry out any other work when the armoured hoses were fitted? Aged seals will make a system soft, other than that it's a matter of keeping the hydraulics meticulously clean. Old pads and shoes are another factor, as are any seized components in the rear drum setup.
It moay of course be a simple matter of air in the system which needs bleeding.
Cheers,
Bill.

[ferny]

air - fully bled the system and the peddle doesn't "pump up"

rears - should be fine as they were adjusted when the system was bled and it wasn't long ago they were taken apart and everything was good

wheel bearings - wheels feel fine and it just passed its MOT

seals - I was told that the peddle wouldn't go hard if they were knackered?

pads - checked about 600 miles ago (there-abouts, maybe) and they were said to be fine




Not discounting what you say, I plan on going through everything and leaving nothing to chance.

So, you're saying that the peddle shouldn't go anywhere near the floor? I looked at old posts on braided hoses (and read your views on them so I'll save you repeating them ;D ) and also saw you say it shouldn't have more than an inch in free-play. I'll have to measure mine but it certainly feels like more.
I guess an easy thing to ask is, what do you class as free play?



The easiest thing to do would be to push someone elses and see what theirs feels like. Easier said than done though. ;D
May go and try a 948 (or was it a 1200) which has drums all round. Doubt it'll help a great deal as it's hardly a good comparison. But, every little helps...

[Nick Jones]

Few thoughts:

How about pedal shaft bush, or, more likely, wear in the clevis pin or clevis itself?

Master cylinder can sometimes give this kind of result.  They don't appreciate lots of bleeding as they have to move over full stroke rather than the part stroke they are used to.

Are you using the right diameter master cyl. for the car.  If too small you will get longer pedal.

Try readjusting the rear brakes.  If they have been apart, they sometimes settle once driven and need nipping up a bit more.

Nick

What's the history? Is it a new build or were they working properly before?

[ferny]

Had a go this morning and felt that they pumped up. So I'm going to bleed them in a second. Then adjust them.

Went round to look at the Herald. It's a 1200 with disc brakes on the front. It also felt nothing like mine! In other words, his felt right and mine felt like they weren't there. They still work, but there's far too much movement.

Quote:

What's the history? Is it a new build or were they working properly before?

When we got the car, for a reason I can't remember, we took the rear passenger side apart and found it wans't working. Weeks later the rear drivers side got so hot it boiled the fluid and burnt my hand by touching the alloy wheel. The brake was sticking on when using the foot brake but the handbrake was pulling it off. I can't remember what was done to fix it :O but all the fluid was changed etc as well. The car was fine after that but out of the blue the problem came back. Not as bad but was getting worse. So we looked at the brakes, all seemed well. Unclamped the flexible hose which had been clamped to stop the fliud draining away and found that the brakes were solid. The hose was knacked. So I replaced all four and here I am now. ;D


Looking at the guys manual it give a slighty different way to bleed the brakes. So I'm going to try that rather than the way I'd been told to do them.

[ferny]

That's better!

Whilst I was round there I read his manual. Every single one seems to have a different theory on how do bleed them. ;D
It said to slam down the peddle hard and to also nip the nipple on the down stroke. Which is different to what I was told to do.

Loads of air came out of the backs and now the peddle takes up just before half way. Still a bit of free-play, but it's amazing how different they feel and how much more control I have. I'll bleed them again in a few days any also go around and check everything else whilst it's in my head.

Thanks for your replies. :)