Easy as 1 2 3 Brake Rebuild

[Dale]

I'm ready to rebuild the calipers on my 1750GTV and will be replacing the caliper parts, pads, hoses, and fluid while I'm at it. I all ready have the car on safe jack stands, the wheels are off and I'm ready to get started.

1. Are there any caps available to keep brake fluid from continuing to drip out of the lines once I have the calipers and hoses off?

Someone provided a nice step by step procedure for me to use in the process. Thanks.

[Chsmadden]

Quote:

Originally Posted by Dale 1. Are there any caps available to keep brake fluid from continuing to drip out of the lines once I have the calipers and hoses off?

[UngaWunga]

I used a piece of old fuel line with a bolt blocking off the other end.

Use some fine grit (800) on the caliper pistons when you have them out. Easiest way to get them clean.

[Alfajay]

Dale:

One of the harder parts of the caliper rebuild operation is getting the pistons out of the calipers. Especially when the seals are hardened and things are dirty/rusty.

The "easiest" way to do it (and "easy" is a relative term here) is to use hydraulic pressure to push them out. With the calipers & brake lines still in place, remove the pads, step on the pedal, and push them part way out. Ideally, once they are most of the way out, you can remove them mechanically (ie. yank them out). Don't use vicegrips though - you'll mar the outside of the pistons.

Compressed air is another solution, though few air compressors generate as much pressure as a brake hydraulic system.

It's seldom easy - either a piston will be totally stuck, or else it will come completely out, puking brake fluid and preventing you from applying pressure to the remaining pistons.

Note that when you reinstall the pistons they must be oriented in a certain way. Your manual will have a diagram of this.

[papajam]

Quote:

Originally Posted by Dale ...to keep brake fluid from continuing to drip out of the lines once I have the calipers and hoses off?

[Dale]

Great tips! I'll take some photos as I go through it, then share here. When I removed the wheels something interesting did pop up. Only the driver front hub had the left hand threads, somewhere around 3cm in length.

Should I take this opportunity to change out the lug bolts? Also, with rotors being fairly inexpensive, is it normal to change these out rather than messing with them?

I'm interested in easy inexpensive upgrades of course. The rotors are very nasty and there seems to be uneven wear on a couple as if they are slightly warped. As I spin them, they drag a little then free up, drag a little, then free up at the same points. I removed the pads from the driver front last night but they were a bear to remove.

Thanks again for the tips!

[Dale]

I thought I'd share a few pics of the process. This was the driver rear caliper.

1. Remove wheel
2. Punch both pins through caliper
3. Pull pads
4. Extend the pistons
5. Remove brake line
6. Unbolt caliper

I was able to free the first piston with my fingers, but the other is in tight. I'm going to let it sit tonight soaking in Liquid Wrench.

QUESTION: What is the best way to remove the last piston without leaving marks. I cannot force it out with grease now that the other is free.

[65Sprint]

Dale,

To work the stuck piston out of the caliper, I put the "free" piston back in and limit its travel with a thin piece of plywood, held in place with C clamps. This allows any hydraulic/pneumatic force to be applied to the stuck piston. The wood also serves as a cushion for the piston to hit when it breaks free. I have had good luck using air pressure but its never easy and if a piston is really stuck, persistence and plenty of liquid wrench or PB Blaster will eventually work. If you use air pressure, be very careful. There's a lot of energy in a caliper piston breaking loose with 100 psi behind it.

[Dale]

I'll give that a try tonight.

[Tifosi]

Sandals on the feet under the rotor with the car up in the air, but wearing rubber gloves while touching brake fluid?

F'shame... That's a permamant limp waiting to happen, but at least your hands will be clean when you go scrabbling for nubbins.

(sorry man, stuff like that just creeps me out in a big way)

[Dale]

Tifosi, Let's see....Each stand rated to 3 tons. Jack points are very solid. I put it up there myself. I check it every time prior to starting work. Why so sensitive??? If I can't trust my own work, what can I trust?

[Tifosi]

Quote:

what can I trust

[Dale]

Death and taxes for sure! Truth be told, I usually wear jeans or overalls when I'm in the garage tinkering. You just caught me in a rare moment. You'd never guess I've taught classes in occupational safety! I'll be back at it tonight and should add more photos this weekend.

[Tifosi]

T'ain't a true shop teacher unless there's at least a fingertip missing

Hopefully that soaking you gave the parts will be helpful by now.

[daveydog]

You know, shop safety can be laughed about and usually it's about nothing, but when it comes to your eyes or appendages no not that appendage, one really does have to be careful. A friend of mine was working on his MGA about ten years ago. He had the car up on two scissor jacks on the front, a couple of 4x4's on one side on the rear, and a one and a half ton bottle jack on the other rear. Working by himself at night after dinner he was trying to rotate his tires or do some brake work I'm not sure, but he managed to push the car forwards and to the left side when, you guessed it, the car landed on his right foot. He was screaming so loud his wife heard him from the livingroom and came rushing out. With his somewhat vocal and feverish directions she was able to get the car lifted off his foot enough so he could pull it from under the car. He had bluejeans and running shoes on at the time and once the pressure had been released, he said the pain wasn't so bad but they went down to Emergency anyways. After it was all over it turned out he had a cracked big toe ( no doubt even bigger by now heh heh) and some bad bruising to the whole foot. He was one of the lucky ones.
Be careful out there fellow Alfa nuts!
And if you just can't be careful, then at least have lot's of ice handy...