Page 1 of 2

Just bled the brakes.....

Posted: Sun May 28, 2006 4:10 pm
by Gareth
And I think they are worse.
Fluid was black so at least it's now clear but there is a little more travel in the pedal.

I have the SBS pads to change to also but little concerned with the state of my disks.

Brakes going to need bled again or will firm pedal feel without travel come back?

Posted: Sun May 28, 2006 4:21 pm
by tenkfeet
Have you rotated the front calipers? If using an eezy bleed I found if you crack the bleed nipple to get a slow flow press the brake pedal mid travel. I screwed up as I let the fluid level in the resevoir drop I then had to do it to get the pedal solid again.

Posted: Sun May 28, 2006 5:14 pm
by Gareth
Not rotated the front?
I bled each brake about 2 or 3 times each.
I haven't pumped the brakes hard yet while driving.

Posted: Sun May 28, 2006 6:03 pm
by tenkfeet
I read somewhere due to the design of the caliper with the lower transfer tube air can get trapped at the rear.

Posted: Mon May 29, 2006 7:53 am
by robin
Did you remove the pads or press back the pistons? IF not then bleeding out the brakes is probably not going to clear out all the fluid in the pistons. Not that this would cause your sponginess. If you did move the pistons back then you will need to bed the brakes back in again briefly before you get a proper pedal feel again.

Most likely is you have allowed air back into the calipers through the bleed nipples (you can get air going in past the threads if you undo them too much).

I suggest bleeding with a non-return valve at the nipple in addition to the pressure bleader and don't open the nipples more than is required to get some fluid flowing. If you can get someone to pump the pedal then it's worth getting the pedal pumped at the end, opening the nipple for each down stroke and closing it for each up stroke.


But, I would change the pads at the same time - that way the pistons are pushed right back and so the fluid in them is expelled. If you can remove the front calipers you can raise them in the air a bit and also turn them upside down during the bleeding process which helps release any trapped air - *but* make sure you leave something between the pistons at all times otherwise you could over-extend them.


Cheers,
Robin

Posted: Mon May 29, 2006 9:29 am
by offshorematt
I didn't arrive until you guys had finished the brakes Gareth but I thought you had been using the non return valve and pumping the pedal technique? If the brakes felt fine when you were sitting in the car pumping the pedal, I don't understand why they would degrade once the wheels were back on? Did you not check them again after we did the clutch? Don't worry, we'll do it again when we finally put your new pads on... :wink:

Posted: Mon May 29, 2006 10:41 am
by Gareth
Here are my disks after bedding in the pads.
I think they're fooked.
Robin??

Passenger side front:

Image

Passenger side rear (looks fine)

Image

Drivers side front and rear look like below You can see the shiney part of the disk - bottom to middle of disk. Top has is still dirty:

Image

Posted: Mon May 29, 2006 11:21 am
by Uldis
Gareth,

so you changed the pads, did this improve the pedal feel? (the fact that the pistons were pushed and the fluid moved).
Did you remove the heavy ridge that was formed? other wise it takes a while for the pads to wear out that lip and meanwhile this contributes to a mush pedal feel.

If not, you should go back to the standard procedure to bleed the brakes: pumping the pedal and opening the bleed nipple. I works because when you press the pedal the bubbles get smaller and they are easier to move.
You'll waste a lot of fluid though but that's Ok.

As a reference, I also have one of those E-Z bleeders, but just use the old system of pumping the brake. Call me old fashioned.


Now, as for the shiny spots, if this is with the new pads, it's likely that the pads are tilted. Why? don't know. Does the piston inside look flat? is it tilted?
If yes, remove the caliper and see if there is any dirt in the base that would make it tilt.
There must be an easy explanation to this, as the pad is touching first on one edge.

Other than that, once the pad lays flat the pitted surface will wear out, don't worry.

Having see the state of your calipers I recommended (and still do) to remove them and clean them thoroughly with a wire brush, clean the seals and see if everything is in shape.

The only way is to give it a good look.

Posted: Mon May 29, 2006 11:33 am
by robin
If you have a heavy ridge at the top of the disk, then the pad will touch there and near the middle - just like the picture in fact!

Drive it hard for a couple of hours and see if things improve - then rebleed if required.

Cheers,
Robin

Posted: Mon May 29, 2006 10:32 pm
by Rich H
My disks looked like that after rutuning from couple of weeks holiday, a good thrashing sorted them out.

When I changed my brake hoses for braided I had to turn the cliper over, loads of air came out, if you aren't getting any air after pushing the pistons back in (Make sure there is space in the resi or you'll get fluid everywhere!) and don't have a ridge on the disk then try it. Wheel off, pads out, 2 bolts (Cheesy allen bolts!) out, connect the easy bleed and turn them over. My pistons didn't move under easibleed pressure, but keep something between them (Block of wood?) just in case. The Caliper bolts are soft as sh*t and must be treated carefully. clean them out first with a bit of wire, and use a good allen socket. I had to tap mine home with a hammer. They will come out with a bang. Don't forget to re-torque them with some thread lock too.

Rich
(In need of a brake bleed too)

Posted: Mon Jun 05, 2006 2:36 pm
by Gareth
A good run on Sunday cleaned them up a little.
2 are nice and smooth and shiney while the other two are getting that way.

Posted: Mon Jun 05, 2006 2:44 pm
by Shug
What about the pedal feel? Did you sort that?

Posted: Mon Jun 05, 2006 3:17 pm
by Gareth
I would prefer it firmer but never had time this weekend.
Didn't feel too spongy on the Sunday run. 8)

Posted: Mon Jun 05, 2006 3:22 pm
by Shug
Good. If there was air, you'd know about it!

Good hard use (fnurk) and regular 'deglazing' jaunts, they'll be fine! :lol:

Posted: Mon Jun 05, 2006 10:14 pm
by simon
How you finding the SBS compared to the greenies?