After a lengthy battle with caliper bolts (torx heads turned into round heads through a previous owner jamming in a hex key and turning) I got my calipers off and replaced my pads. During this happy fun time I noticed the e-brake cable wasn't hooked up to the actuator, probably because, as I found, the nut that is supposed to retain the lever on the back of the caliper won't on the shaft. The whole shaft will turn, which causes it to move in or out drastically, and when it moves inwards it starts spewing brake fluid. WTF?

There are supposed to be rubber seals there, if it is spewing fluid out, your caliper's seals are shot... get a re-build kit or get a new caliper.

I am doing rear brakes on my 86 right now...

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AL' Owner of:

88 Coupe (crashed)

87 GT V6 (crashed)

86 Sport I4 (Needs Rr. Brake job and fuel pump)
(January's project)

85 SE V6 (Needs trans. flush and fuel pump)
(Febuary's project)

see ogre's cave - top o page

You turned screw in w/o lever and nut?
It's normal.

Not normal if you turn screw out and seal won't seal again.

And note... you have to bleed that caliper.

Yes... see cave, brake service and rear brake.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 01-18-2011).]

It seals again when I turn it out. Thanks, guys.

Not quite sure from your wording but is the nut that holds the lever on missing? If so then it will surely leak since that nut also holds the seal tight.

No, the problem is that that nut was put back on without the lever being installed, and now it won't come off-there isn't enough space to get on the smaller nut or bolt head under it with a normal box end, and the cheap one that I ground down to fit snapped off when I tried that. :P

Seal and plastic washer you can see is just a dust boot.
2nd seal in actuator/case interface keeps fluid in. Turn actuator in and seal will leak. Nothing prevent actuator from backing out except lever and nut.
See cave, rear brakes, how it works link at top of page.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

[This message has been edited by theogre (edited 01-18-2011).]

quote Originally posted by theogre: Seal and plastic washer you can see is just a dust boot.

That's not correct. The "dust boot" is a thrust washer, and your e-brake will not adjust properly without it. The thrust washer keeps the play in the shaft and lever to a minimum. Too much play in the shaft, and the e-brake won't adjust.

quote Originally posted by Formula Owner: That's not correct. The "dust boot" is a thrust washer, and your e-brake will not adjust properly without it. The thrust washer keeps the play in the shaft and lever to a minimum. Too much play in the shaft, and the e-brake won't adjust.

That dust boot/seal/whatever does nothing to seal hydraulic pressure in and air out and function? I left out allot of things that doesn't matter to problem at hand. Hell I left stuff out in my Cave on purpose...

Thin plastic washer is there so seal won't get stuck to lever and tear up. Thickness of dust boot/seal/etc keeps dirt out, takes up slack and gives room for thermal cycles. (Al caliper and steel actuator & lever.... Different metal needs different thermal property, IE needs room to grow/shrink.)

Seal has a indent for washer that fits in. Goes on actuator in order... seal with indent toward lever, plastic washer, lever, nut.

Important to overall caliper health and needs to put back it...

back to question...

I reread the first post again... Nut allows actuator to back off? Nut was tight?

Did actuator have the parking brake lever and/or dust boot seal? actuator can't back off enough with lever, or maybe dust boot seal, is missing to. You needs all the pieces... dust boot/seal, lever, nut, cable spring, etc, even if you cut/remove parking brake cable. See cave, rear brake. This will happen again if you lose lever or boot seal.

Did you also have dust boot/seal and plastic washer?
No? Get a seal kit or get a rebuild caliper.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Well, I finally got it apart-I do have the 'dust boot' and plastic washer etc. Now I have another problem (of course )

Well, I don't know if it's a problem or not. I have it all back together correctly as far as I can see. Now-when I turn the parking brake actuator with the attached lever, it pushes the brake piston outwards so as to lock the caliper against the rotor. Should it visibly retract when I turn the actuator the other way? It does not, currently-I think something inside the piston is turning along with the shaft instead of pulling the piston back in. Is this normal, or is my piston fubar?

In normal operation the piston will not be retracted noticably. The guts of the piston that the parking brake assembly screws into is designed to act like a one-way clutch. It slowly creeps in as the pads wear so that you don't get too much slack between the pads and rotor surface. When you release the brakes (parking or pedal, either way) the piston is slightly retracted by stiction in the caliper pressure seal, and also by normal runout in the rotor itself. If the caliper seal is old and stiff then the pads may drag the rotor slightly, resulting in a slight increase in wear and decrease in gas mileage.

Sweet. Thanks again.

quote Originally posted by Tyrfin: The emergency brake even works perfectly-put it in neutral on a hill and it just sat there at a 20 degree angle.

Well, that's half the battle. Make sure it releases properly as well.

I checked that before I drove it. Having to replace a destroyed rotor because of someone's idiocy once was bad enough without it being my OWN idiocy.

quote Originally posted by theogre: Seal and plastic washer you can see is just a dust boot.

quote Originally posted by Formula Owner: That's not correct. The "dust boot" is a thrust washer, and your e-brake will not adjust properly without it. The thrust washer keeps the play in the shaft and lever to a minimum. Too much play in the shaft, and the e-brake won't adjust.

quote Originally posted by theogre: That dust boot/seal/whatever does nothing to seal hydraulic pressure in and air out and function?

The thrust washer doesn't act as a seal, but it does allow the existing seal to work properly. Without this washer, the shaft will travel too far into the caliper, and the surface of the shaft that SHOULD be in contact with the seal will then only be barely in contact. The result won't be a huge leak. On mine, the missing thrust washer caused a drop to seep out every so often. The back of my caliper was wet with brake fluid, but there was never any fluid on the ground. Oh, and my e-brake wouldn't adjust properly until I replaced that washer.

quote Originally posted by theogre: Thin plastic washer is there so seal won't get stuck to lever and tear up. Thickness of dust boot/seal/etc keeps dirt out, takes up slack and gives room for thermal cycles. (Al caliper and steel actuator & lever.... Different metal needs different thermal property, IE needs room to grow/shrink.)

There are no plastic washers on the calipers on my Formula. Only a single metal washer with a rubber (or maybe silicone) coating, which fits tightly between the caliper and the park brake lever. Tight enough that there's no room for another washer, so I'm fairly confident that my calipers don't use any additional washers there.

Guys,

I am going to be replacing the rear calipers on my 86GT.

Is there any Walk through with pics or videos I can reference?

This will be my first time replacing calipers and from what I have read the Fiero calipers are quite involved...

Let me know.

Thanks

Is the actuator supposed to fit over the lower nut?

quote Originally posted by theogre: Seal has a indent for washer that fits in. Goes on actuator in order... seal with indent toward lever, plastic washer, lever, nut.

Sorry Ogre, but I've got to question this. I'm presently working on the rear calipers on my '86 GT, and when I took the levers off, I discovered that the lever seal (#10) and plastic anti-friction washer (#9) are reversed from what you've stated (unless I'm misunderstanding what you posted). I checked the service manual, and sure enough, the thin anti-friction washer goes against the caliper body (not the lever) and then it's the lever seal (with the indent towards the washer and caliper body) followed by the lever itself and then the nut.

Is the service manual wrong regarding this? I know that this is possible, as the brake bleeding sequence mentioned in the manual is incorrect for a Fiero.

Comments?




[Edit to add] Interesting looking return spring (#25) shown. Did Fieros ever have that style?

[This message has been edited by Patrick (edited 10-01-2012).]

Both of mine went in this order..
Little metal ring thingy
Dust boot
Actuator
Nut

Got my leak fixed it was just loose and the shaft was too
Deep in the caliper..
I read the stuff in ogre cave but still can't get my parking
Brake to work?
I turned the shaft out clockwise as far as it goes
Put it all together, bled. No park brake
Did the pedal pumping and pulling e brake thing a hundred times
It moves the actuators but not far. Tightened the whole way
Lots of slack..

Save some money and just swap to grand am calipers and rotors, super cheap, direct fit, better stopping!

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86 Fiero GTX project soon to tear up the street, My build thread! 3800sc, interior, wheels and more! https://www.fiero.nl/forum/Forum1/HTML/089483.html

quote Originally posted by Patrick: Sorry Ogre, but I've got to question this. I'm presently working on the rear calipers on my '86 GT, and when I took the levers off, I discovered that the lever seal (#10) and plastic anti-friction washer (#9) are reversed from what you've stated (unless I'm misunderstanding what you posted).

See 87 SM... GM finally corrected the rear.

Yes... I reread 87 SM and you're right...
I read

quote 9. Reinstall anti-friction washer (7), lever seal (6) (sealing bead against housing), lever (2) and nut (1) (Figure 2). [Page 5B8-1]

and I flipped info my post above and didn't see it. I think I missed bead and read "seal against" not "seal bead against."
Away sorry...

quote Originally posted by theogre: Away sorry...

Dave, no need to apologize. It just goes to show that an Ogre is indeed... human.

"The ogre"

Come fix my Fiero. Thank you.

[This message has been edited by Kenn07 (edited 10-01-2012).]