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!
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.
Hachiroku $B%O%A%m%/(B wrote in news: snipped-for-privacy@e86.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.
"hls" wrote in news:c7Odnd-c84txUVLXnZ2dnUVZ snipped-for-privacy@giganews.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.
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. :-)
Since it's rear shoes it's a wheel cylinder. Cheap to replace. 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.
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...
Actually, it's only been mine for about 2 years, and winter only. What I DO remember is, when I park that car and then take my '89 Mazda for a spin, I almost put myself through the windshield when I hit the brakes the first time!
That makes sense. Car has 2 brake diagonal circuits. RF and LR is one circuit and the LF and RR is the other. You have air in the circuit you didn't bleed. Your brakes will always suck until both circuits are bled. No getting around this.
Hachiroku $B%O%A%m%/(B wrote in news: snipped-for-privacy@e86.GTS:
The later Tercels sold so poorly in the US that Toyota stopped imports after the '98 MY. The rest of the world (including Canada) did get the '99 Tercel.
2000 was the first year for the Echo.
Oddly, even though the '99 Tercel was never sold in the US, the Canadian- market '99 Tercel has a California-certified engine. Figure that one out.
I'm going to try, very gingerly, to loosen the stuck bleeder tomorrow.
Also, the pass side caliper was stuck in the open position, and after an hour with emory cloth, Dremel, Syl-Glide and a Mighty-Vac seems to be working OK. The puck wasn't stuck, the sliders were.
Interesting thing: I beld the brakes the other day, and juice was flowing out, but when I did the pass side caliper the pressure was building and building and all of a sudden there was kind of a SLURP! and the juice started filling the cup. I looked and didn't see anything, but considering I just about completely refilled the cup 3 times the other day, it sure was dirty.
When the pressure builds that way and then just pops loose, the interior lining of the brake hose could be deteriorated. A loose flap from the lining could act as an obstruction, resulting in a spongy feel with poor braking performance. On the wheel in question, if applying the brakes doesn't move the caliper piston and you know the piston and sliders are free, then the hose is suspect.
Hoses are cheaper than calipers - the hose in question would be the flexible one between the body and caliper or wheel cylinder, not the metal brake line from the master cylinder to the flex hose. You will probably need a flare nut wrench to break the connections free. IIRC, you will need a 10 mm wrench on a Toyota, probably the same on a Subie.
I took a look at the setup when I did the other side this morning. Yeah, they join at the inner fender. Doesn't look too tough. I sprayed it with GM Heat Riser Lubricant (IMHO, much better then Blaster...) and the hose is $22 from AZ, but I'll bet it's cheaper from a Suby dealer. Most of the parts I've bought for this have been! (Go figure!)
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