rdroe

Just buttoned up the front end. New upper / lower a-arms, shocks, springs, all new ball joints, tie rod ends, cross drilled rotors, steal braided line, etc. AND new factory stock calipers. Power bled the brakes with no more than 15PSI in the official power bleeder. Forget what the device is called, but the one everyone recommends with the MC top held on by chains. Sort of looks like a small garden sprayer. Did not even take it out of the garage but 10 ' to *seat* the bushings. Then removed the right front wheel and noticed a small puddle of brake fluid! Arg. Not coming from the line fitting into the caliper. Not coming from the EZ bleed fitting. Dripping from the bottom of the rotor. I have only 2 guesses.

1. The 2 halves are not torqued to spec from the rebuilders of the calipers, or ..
2. One of the 4 pistons are leaking. I suspect that since they are factory replacement (Advanced Auto) that they are edge seal and not o-ring.

Tearing it down later this weekend and going to take out the pads and put small wooden spacers in to simulate the pads. That way I can *see* the pistons.

Any bets? THoughts? It is a small thing I know, but it just PISSES me off!

gbvette62

Once you pull the caliper, you should be able to see if a piston seal is leaking.

O-ring or lip seal, it doesn't make any difference, they can all still leak. The main advantage to o-ring calipers, is that they are less likely to leak when used on cars that don't get driven much.

Rebuilt calipers have been known to leak. Sometimes it's a problem with the installation of the seal, sometimes it's because the caliper has been sitting around to long and the seals have dried out. Years ago, before everyone was sleeving calipers, freshly rebuilt calipers would occasionally leak because of pitting left behind in the cylinder bore.

As I'm sure your aware, $$it happens! I hope it's an easy fix for you.

Peterbuilt

You have to install the pads evenly, if one side goes down first the lip seal can get out of position and leak.
Picture is NOT a C-3 caliper but you get the idea.

rdroe

hmmmm.... using your diagram above, in concept, are you suggesting to just remove and re-install the pads to fix? I can do that really easily....

Shark Racer

I think he's saying if you **** the piston when installing the pad you run the risk of pulling the piston seal out of its seat.

Fixing this would require reseating the seal.

rdroe

Ok, thanks. I will take the wheel off, then the pads and peek inside. should be obvious what is leaking. Then use some wood blocks the size of the pads to keep the pistons in place and have my son apply the brakes to see what is what. Always something. RIght before I rip into the back end with the *plan* for the winter.

Shark Racer

When I first started driving, every time I came into some $$ (bonus check, birthday gift), I swear one of the calipers on my 78 started leaking. (It was my first car and drove it through HS and college)

rdroe

And here is the bad thing. I painted the calipers so if I have to return it, I can't. Not that big of a deal, but ....

Another question to the experts: Using the stock caliper bracket, what are my options for 3rd party performance calipers? Meaning I would love Wilwood, but can't afford them. Are there some moderate calipers? Maybe aluminum?

drwet

I had a similar problems when I replaced the calipers on my 79 a couple of years ago. Pulled in to Minneapolis on a road trip and discovered the right front was leaking. Had the wheel off a couple of times to figure out where the leak was. tough to tell because there was fluid everywhere. Tightened the line fitting a couple of times and kept adding fluid. Finally my buddy was convinced I wasn't getting it tight enough, so HE put the wrench on it and pulled a lot harder than I was comfortable with. Solved the problem. I just wasn't getting enough torque on the bolt to crush the copper waher enough to seal. I was convinced it wasn't the connection that was leaking, but it was. Check carefully, and don't be afraid to get it really tight.

rdroe

You know, that may be it. it is above the point of vertical. I was afraid to go overly tight. And if I bugger it up, I can always replace the hose. I will try it tonight. Easy fix and easy test! Thanks.

One of the mottos that I live by is that "if someone else built it, then I can fix it". I try not to fall into that feeling of "Oh Sh*t, now what" and panic. I can buy another part, and I can use my mind to fixit!

rdroe

I just checked the leak without touching a thing. Its coming from the 2 halves on the upper side where they join together. SO I re-torqued the bolts to 130 as per spec, and .... still leaked! Arg ... maybe Wilwood after all. So much for standard Advanced Auto calipers. I now begin the hunt.... Zips, Corvette Central, etc.....

Anyone use the WilWoods that bolt to the standard caliper brackets?

mds3013

You could split the caliper. Sand the mating halves and install new o-rings between halves. Front calipers use two o-rings, rears use one. mike...

rdroe

That's what I'm thinking. I guess who ever rebuilt them, forgot the o-ring, and luck would have it, I found the issue. Better now then riding down the road.

I am still going to focus on maybe a good deal on Wilwood D8's. So far, the best deal is $1000 from CC. $1100 in red. Anyone seen any better? Where are those coupons when you need them!

drk1313

I just fixed the same problem with my '71 thanks to this thread. Two lousy o-rings is all it took! After I re-bled the brakes, they are better than ever. You can't beat an easy fix.

rdroe

I know that I should fix it that way..just can't get Wilwoods off my mind! Talk me down from the Wilwoods ledge! Help me! Got checkbook in hand for some sweet aluminum calipers!

sly vette

If you want to impress people visually,get the Wilwoods.
If you want to save some big cash and have brakes that will handle anything you can throw at them on the street,replace the O-Rings.
Yes...The stock units are much heavier but in most instances you will not appreciate the weight savings with a street cruiser.