Caliper Leak

Post by **Sluggo** » Fri Dec 14, 2007 10:36 am

Two days ago I noticed my brakes started to get squishy. Took a look at the brake fluid reservoir and it was empty. Looked under the Bus (which was slightly painful because I'm still recovering from that accident) and noticed fluid all over the back of the right front tire.

Upon further inspection I saw that it was all over the inside of the rim and rotor too. I checked and it's not the hoses or solid lines.

So I am assuming this means I need a new caliper.

Problem: I can't do this right now. My shoulder is still a little messed up. I could do it and work through the pain but that would probably make my shoulder worse. Plus if anyone saw me I could ruin my case with the other drivers insurance company.

I wish Colin was around.

And before anyone says it, the brakes were fine and worked great the day of the accident. This started more than a week later.

RSorak 71Westy · Post by **RSorak 71Westy** » Fri Dec 14, 2007 2:24 pm

It would be very strange for a caliper to just start leaking out of the blue. I'm not saying it's not possible, just very very rare. If it's not leaking too fast you can just keep the fluid topped up and keep on goin. Ideally calipers should be replaced in pairs.

Post by **Sluggo** » Fri Dec 14, 2007 4:00 pm

RSorak 71Westy wrote:It would be very strange for a caliper to just start leaking out of the blue. I'm not saying it's not possible, just very very rare. If it's not leaking too fast you can just keep the fluid topped up and keep on goin. Ideally calipers should be replaced in pairs.

I think it may have happened because of the accident. It's not too far back from the impact point. Maybe the jarring from inpact did it.

I figured it should be done in pairs. I should probably do the pads too because they've been coated in brake fluid.

RSorak 71Westy · Post by **RSorak 71Westy** » Sat Dec 15, 2007 8:42 am

yes the pad that's fluid soaked is trash. And I can't see the accident causing this either....Calipers are very simple and very robust.

Post by **Amskeptic** » Sat Dec 15, 2007 11:04 am

Sluggo wrote:
I think it may have happened because of the accident.

Entirely possible if you really stomped on the brakes. If your torsion arms did a quick jerk into the stops, you might also want to run your 11mm wrench over each connection just to make sure that they are snug, You can develop hairline fractures if they are already too tight and the line took a torsional yank.
What I would do if I were an injured you is merely check connections and hoses and replace the pads. Are they worn?
Just by having fresh pads with the pistons retracted to a different spot, you may discover that the leak is gone because the seals are in a different location in the bore. Clean everything thoroughly at replacement time. Keep a close eye for a subsequent leak. If one shows up, yank the new pads before they get contaminated.
Colin

hambone · Post by **hambone** » Sun Dec 16, 2007 2:02 pm

Do front disk brakes require periodic adjusment like drums do?

Westy78 · Post by **Westy78** » Sun Dec 16, 2007 2:11 pm

hambone wrote:Do front disk brakes require periodic adjusment like drums do?

Nope, it just takes more fluid to press the pads into the rotor as they wear. Or more correctly, presses the piston into the pad then into the rotor.

hambone · Post by **hambone** » Sun Dec 16, 2007 2:25 pm

No wonder people love disk brakes!

Post by **Sluggo** » Sun Dec 23, 2007 11:15 am

Went & saw Linda Costa (Bob Costa's Widow) and got some calipers. Installed them (with one arm, using my legs for torque) and now I can stop. I got a few questions though.

1. Piston Indentation:
There is an indentation in the lip of the pistons on the calipers. The old calipers had it on the bottom, the new ones have them on the top. Before you say switch sides, they were marked right & left. Were the old ones on wrong or are the new calipers marked wrong?

2. Brake Pad Backing Plate:
There isn't one. Do I need it? Didn't come with the new calipers or pads.

3. Brake squeal:
I got it. How do I get rid of it?

Westy78 · Post by **Westy78** » Sun Dec 23, 2007 1:22 pm

Sluggo wrote:

3. Brake squeal:
I got it. How do I get rid of it?

Get number two. Two tabs on the plates should fit into the indentation on the pistons. If not the pistons will have to be rotated for the tabs to hold the backing plates in the proper position.

Post by **Amskeptic** » Sun Dec 23, 2007 1:53 pm

Sluggo wrote:Went & saw Linda Costa (Bob Costa's Widow) and got some calipers. Installed them (with one arm, using my legs for torque) and now I can stop. I got a few questions though.

1. Indentation:
2. Brake Pad Backing Plate
There isn't one.
3. Brake squeal:

Amazing how this stuff is interrelated isn't it?
The (1) indentation of the pistons at the leading edge (bottom) is what prevents (3) squealing, the (2) shims locate the piston indentations correctly. (!)

Post by **Sluggo** » Sun Dec 23, 2007 1:58 pm

Amskeptic wrote:Amazing how this stuff is interrelated isn't it?
The (1) indentation of the pistons at the leading edge (bottom) is what prevents (3) squealing, the (2) shims locate the piston indentations correctly. (!)

So basically, I have to pull the calipers again, switch sides (The bags and calipers were marked opposite apparently), and hope Linda didn't return the cores yet so I can get my old backing plates back.

What could happen if I leave them as is for a week?

Post by **Amskeptic** » Sun Dec 23, 2007 2:03 pm

Sluggo wrote:
Amskeptic wrote:Amazing how this stuff is interrelated isn't it?
The (1) indentation of the pistons at the leading edge (bottom) is what prevents (3) squealing, the (2) shims locate the piston indentations correctly. (!)
So basically, I have to pull the calipers again, switch sides (The bags and calipers were marked opposite apparently), and hope Linda didn't return the cores yet so I can get my old backing plates back.

What could happen if I leave them as is for a week?

The calipers have different size bolt diameters. They can only go on one way. Just rotate the pistons so the indentations are facing down with a little tilt to match the arc of the rotor. If you can view a picture of the pad shims on some vendor site, you can see exactly what the angle is. Rotating the pistons is a little annoying, be careful of the dust boots, but I do it at almost every Itinerant Air-Cooled stop and only the totally frozen pistons are impossible.
Colin