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| Caliper Leak (Page 1/2) |
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Notorio
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DEC 18, 05:54 PM
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As many of you know I'm putting my 88GT back together after some engine work with 18 months flying by. I noticed that the driver rear suspension looked a bit greasy. Thinking it was some engine cleaner that hasn't evaporated I took the brake apart and notice much oily muck that looks like it has been flung out from a small leak. The black paint on the back of the inboard pad has been softened up and eaten away, clearly the work of brake fluid.
In this picture there is a large gash in the boot and a small drip exuding from the small seal. Guess this means the piston inside is leaking a bit. AFAI recall from 18 months ago the brakes seemed to be working fine. Looks like I'm going to need to get a rebuilt caliper for this.
In this second picture I'm deeply suspicious of these two large washers going in between the two halves of the caliper. Without taking the other side apart it looks like this is a rig from a prior owner. Can anyone confirm these washers don't belong here?
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theogre
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DEC 18, 06:49 PM
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1. Leaking thru dirt boot anywhere = main "o-ring" behind it is "bad" and can be fixed...
If that's top of the boot, boot is likely full of crap, water, and brake fluid. Main O-ring leaking can be any where and not = same bad spot in a boot.
But...
2. Leaking thru front "vent valve" = piston is bad. More specific Inner piston and Seal you never see have failed.
See my Cave, Rear Piston notes etc. because most of 88 is same rear brake design as older Fiero.
Be Warned that Any "method" to "fix"/"rebuild" a bad piston often fails again and when does can cause pad drag and other problems leading to brake failure or even a fire.------------------
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
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theogre
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DEC 18, 06:55 PM
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And yes... the washers are signs of a moron working on brakes.
Likely idiot can't retract bad piston and new pads won't fit so made more clearance then sold the car.
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Patrick
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DEC 18, 07:13 PM
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| quote | Originally posted by Notorio:
In this second picture I'm deeply suspicious of these two large washers going in between the two halves of the caliper. Without taking the other side apart it looks like this is a rig from a prior owner.
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Wow, some people should not be allowed to work on cars... especially brakes!  That's scary.
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Notorio
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DEC 18, 07:24 PM
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Thanks Ogre. That is such an excellent write up on the rear brakes! I'm glad to see the caliper can probably be saved, since only Autozone appears to have a rebuilt caliper available (nada on O'reilly, Advanced Auto, Rockauto, Napa, and The Fiero Store). Looks like I will need to order parts, a piston is available, and also include this find by Silicoan86 specifically for the 88 ...
1988 Rear Brake Caliper Internal Piston Seal Found
| quote | Originally posted by Patrick:
Wow, some people should not be allowed to work on cars... especially brakes! That's scary. |
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Eons ago when I lived in New Jersey I used to drive past this auto shop with a sign out front on top of which was an upside-down small import car, and a motto claiming 'We stand in Front of Our Brake Jobs.' This PO washer guy, not so much. Please don't remind me there may be other goodies in store ...  [This message has been edited by Notorio (edited 12-18-2019).]
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cvxjet
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DEC 18, 11:05 PM
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You can send your caliper to Centric and they will rebuild it- but that inner seal is a problem; I rebuilt mine with that seal from Centric that Silicoan86 came up with- they seem to work fine, but I agree that they were not designed to be rebuilt.
There are only two alternatives when inner seal fail; Park it.......Or convert to other brakes. There is absolutely no source for new calipers or even pistons.
I have picked up 3 sets of 88 calipers from the JYs in the area for the Golden Gate Fiero club- I suggest everyone grab the 88 calipers out of junked Fieros- never allow them to go to the crusher!
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Notorio
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DEC 19, 10:56 AM
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| quote | Originally posted by cvxjet:
There are only two alternatives when inner seal fail; Park it.......Or convert to other brakes. There is absolutely no source for new calipers or even pistons.
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The devil is truly in the details ... the pistons on Rock Auto are all for FRONT calipers. Can front and rear pistons really be different? Also, the rebuilt rear driver side caliper on Autozone shows as available to 'ship to home' but once you put it in your Cart and check out the system reports they don't have it. [This message has been edited by Notorio (edited 12-19-2019).]
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cvxjet
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DEC 19, 11:37 AM
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I went thru a similar situation a year or so ago; Tried to find a right rear and everywhere I went they no longer carried them, "No stock" or "Unavailable".....Called the technical support line at Centric and the guy went down and found the parts and had one built up for me. Obviously, that is not going to be repeatable- they are OUT of spare parts.
Installing a front piston in a rear caliper- don't know if you can do that, but I know some people have installed FRONT CALIPERS in back; The one problem being you then have no parking brake (The rear Pistons are critical to parking brake function) Supposedly, they have add-on parking brakes out there.....But you have to come up with a way of mounting them, etc....
 [This message has been edited by cvxjet (edited 12-19-2019).]
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Larryinkc
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DEC 19, 12:38 PM
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Notorio
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DEC 19, 01:59 PM
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That is a great find on the rebuilt calipers. Unfortunately for me I don't think my caliper will qualify for a Returnable Core, which raises the price to $175. Turns out there is a large gouge on the piston outer surface. The inner piston retaining ring looks like it has been beat to hell and the bearing is in pieces
Ogre called it on the sludge ... check this out
The brake fluid that drained out of the piston was also dark brown ...
Looks like I will head over to the Mall and see if anyone is able to sell me a caliper ...
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