Rear caliper brake fluid leak

Maintenance advice to keep your Spider in shape.
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Zoofly
Patron 2020
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Joined: Thu Feb 15, 2018 4:14 pm
Your car is a: 1978 Fiat 124 Spider
Location: Los Angeles, CA

Rear caliper brake fluid leak

Post by Zoofly »

I have a leak coming from inside the rubber boot on the rear drivers side caliper. What would be the likely cause of that? The brake line and hose are fine. The parking brake cable is chewed up and brittle but don't think that is the cause of a leak.

This photo is from the bottom looking up. You can see a bead of brake fluid on the left of the photo where I cleaned it up.

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2020 124 Spider Abarth
2019 Alpha Romeo Stelvio - sold
1977 Triumph Spitfire
2017 Fiat 124 Spider Classica - sold
1999 Jaguar XK8 - sold
1998 BMW Z3 - sold
1988 Pontiac Fiero - sold
DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: Rear caliper brake fluid leak

Post by DieselSpider »

Check to ensure that the bleeder is closed and not seeping. Aside from that its the o-ring seal in the e-brake activator where it goes into the back of the caliper or the piston seals.
18Fiatsandcounting
Posts: 3798
Joined: Fri Mar 15, 2019 11:23 pm
Your car is a: 1969 and 1971 124 spiders
Location: San Francisco Bay Area

Re: Rear caliper brake fluid leak

Post by 18Fiatsandcounting »

Zoofly wrote:This photo is from the bottom looking up. You can see a bead of brake fluid on the left of the photo where I cleaned it up.
I never did see the bead of fluid you were referring to, but I looked again at the photo just now and I think I see it. You're talking about what looks to be a small pool of fluid on the square end of the e-brake lever, right?

Since you have fluid coming out of the rubber boot that covers the e-brake cam and plunger assembly, I agree with DieselSpider that it's very likely that your fluid leak is the small o-ring seal on that plunger, inside the caliper. The solution is to rebuild the caliper with new seals all around. It's not as easy as doing the front calipers, but it's do-able if you're mechanically inclined.

-Bryan
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Zoofly
Patron 2020
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Posts: 129
Joined: Thu Feb 15, 2018 4:14 pm
Your car is a: 1978 Fiat 124 Spider
Location: Los Angeles, CA

Re: Rear caliper brake fluid leak

Post by Zoofly »

You were both correct. It was the O ring on the plunger that was causing the leak. Much appreciated.
2020 124 Spider Abarth
2019 Alpha Romeo Stelvio - sold
1977 Triumph Spitfire
2017 Fiat 124 Spider Classica - sold
1999 Jaguar XK8 - sold
1998 BMW Z3 - sold
1988 Pontiac Fiero - sold
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