1989 Suby GL Coupe, AWD.

Spongy brakes. I did the obvious and flushed/bled, but it didn't help a
lot.

I got a set of pads and waiting for the weather to clear. This car has
disc fronts and drum rears. When I did the flush/fill I was unable to
loosen the bleeder on the left rear backing, and didn't want to snap it
off, so that one is not flushed, but what came out didn't look too bad,
anyway.

One thing; the car has been siting since April, and the rotors were rusty.
After just a few miles the driver's side rotor came clean, but the
passenger's side just has a 1" stripe in the middle of the rotor. I'm
going to have a look at that caliper and see if it's stuck open, scuff the
rotor with a wire brush and install the pads and see what happens.

Too bad the rest of the car didn't stay as nice as the motor and
tranny...they're great.

And parts are becoming scarcer than parts for my Supra!

"Hachiroku ãƒ�ãƒ�ãƒ*ク" <Trueno (AT) e86 (DOT) GTS> wrote

At some time or the other, you are going to have worry that bleeder valve
free (or snap it off in the caliper assembly). Usually, but not always,
you
can make them yield. I have snapped one off only one time in my life.

Since you havent replaced the pads yet. maybe you should free up everything
when you put your new pads on. If the old pads are sort of welded in by
rust, then wire brush everything when you put it back together to be sure it
is taught, but moving. I have seen new clean pads that had to be adjusted
to
the caliper mount.

Most calipers are not that hard to rebuild. If I were going to do it, I
would
do both sides. I would emery cloth the pistons and cylinders, wash them
out with methanol, and reassembly with new elastomers and seals. Then
flush like crazy.

Whether your old discs (rotors) are worn unevenly or warped will have to
be evaluated.

=?iso-2022-jp?q?Hachiroku_=1B$B%O%A%m%=2F=1B=28B?= <Trueno (AT) e86 (DOT) GTS>
wrote in newsan.2009.10.09.22.46.24.990948 (AT) e86 (DOT) GTS:


Spongy brakes can mean a lot of possible problems. In no particular
order...

1) Air still in the lines. It can be difficult to budge stubborn bubbles
in the calipers without removing them from their mounts and using the
"turn and tap" method.
2) Aftermarket pads that are too hard. Requires excessive pedal pressure
to make them function.
3) Seized pistons somewhere. Makes the ones that do slide well work
extra hard.
4) Flex hoses that expand when pressure is applied. This happens when
fluid is not changed in a timely manner.
5) Other parts not moving properly, such as pads, pins, etc.
6) Rust buildup anywhere in the caliper assembly components. A Dremel,
Sil-Glyde, aluminum anti-seize, and 50-grit emery cloth are your
friends.





Then you have a sticky piston.

Here's a trick: Eject the piston far enough that you can get a Vise Grip
or set of Channel Locks on the piston lip. You do NOT want to span the
piston, but grip it at one spot between the outer and inner surfaces.
Now clamp down hard and turn the piston. It will probably be mightily
difficult to turn the piston, and the Vise Grips will probably slip and
gouge the metal, so clamp HARD. And have a file handy to clean off the
burr that will surely be created.

Then you need some silicone grease. AGS's Sil-Glyde will do. Then you
need a plastic syringe from a woodworking store, with a really big
nozzle. You clean off the rubber boot with brake cleaner spray, eject
the piston an inch or so, then inject Sil-Glyde under the boot with the
syringe. Now work it round and round, in and out, repeatedly.

Chances are good the piston will free up really nice. Unless it's choked
with rust and gum, of course. Eject the piston, pinch the boot, and look
inside to see how clean the piston is.




Don't scuff the rotor. Free the piston, then let the brake pads do the
scuffing for you.



That's one big problem with owning older cars that aren't considered
"collector" cars. I'm even running into parts unavailability for certain
trim components with our '99 Tercel.


--
Tegger

"hls" <hls (AT) nospam (DOT) nix> wrote in
news:c7Odnd-c84txUVLXnZ2dnUVZ_qydnZ2d (AT) giganews (DOT) com:



Hachi's seized bleeder is in a rear drum cylinder.





Then you don't live in a place that has significant snow each winter.
Leave them for a few years in that case and permanent seizure is a
definite possibility.





That's true for the fronts. Rear calipers that incorporate parking brake
meachanisms are wildy complicated and a lot more difficult to restore.





Agreed. To make sure both sides end up with equal characteristics. I'd
NEVER rebuild or replace just one on an axle set.




I would not. Run your fingernail down a brand-new piston. Does it hang
up or catch anywhere? No. Now run your fingernail down a surface that's
been emeried even with fine cloth. /Big/ difference. Any roughness will
result in a sticky piston, plus it will wear the hydraulic seal very
quickly. Emerying the cylinder bore is somewhat less objectionable,
provided it's cleaned thoroughly afterwards.

Clean off any gum on the pistons with solvent. If rust remains or if the
cleaned surface catches your fingernail anywhere, replace the piston.



--
Tegger

Hachiroku $B%O%A%m%/ wrote:
My guess is that you'll have to replace that rotor as well as the pad
and it would probably be a good idea to replace that caliper too. I once
had the caliper lock up on my 84 GLC wagon. This occurred after doing a
hard stop. The steering wheel got yanked out of my hand when I tried to
accelerate. That was weird.

As I recall, the parking brake was on the front wheels and in order to
change the pads you'll have to screw the caliper piston clockwise to
retract them - you can't push them in. Now that I think about it, new
calipers might be on the expensive side.

My Subaru had the hill-holder feature which was pretty nifty. This
system will retain brake line pressure when you push in the clutch while
braking. It gets activated when your car is on an uphill slope. You
should learn how how to adjust it cause when adjusted correctly, the
darn thing works great. My guess is that not many people would be able
to adjust these so you're better off learning how to do it.

The timing belts on the car had a service life of 60K miles. One of them
snapped at 61K miles. I'd say that's pretty remarkable engineering in
anybodies book. :-)

On Fri, 9 Oct 2009 18:53:11 -0500, "hls" <hls (AT) nospam (DOT) nix> wrote:


But I've sometimes just bled at the line connection instead, and
had no sponginess. And people define sponginess differently.
Sometimes it's normal pedal travel.
But it's his car, so he knows how it should feel.

--Vic

On Fri, 09 Oct 2009 15:12:24 -1000, dsi1 wrote:

Yeah, calipers are too much. The car was $400, and is rusting. The thing
is, it runs so darn well!

I'll have a look at the caliper and see if it can be resurrected. It's not
leaking, at least...

The automatic does all that...automatically!
Too bad it's only a 3-speed...4,000RPM on the highway!

Snapped just about a year ago. Never done one before, and it couldn't have
been much easier!

On Sat, 10 Oct 2009 00:03:01 +0000, Tegger wrote:

Got 'em all! Learned on the Supra.

On Sat, 10 Oct 2009 00:03:01 +0000, Tegger wrote:

Thanks for the tips on the piston.

Running out of parts for a '99?!?! (did they *MAKE* a '99? I thought it
ended in '98 and the Echo took over. )

On Fri, 09 Oct 2009 18:53:11 -0500, hls wrote:

Thanks.

The funny thing is, the other day there was a LOT of push-back on the
pedal, but as I surmised, it must have been rust, because the pedal is
smooth as silk now...