engine and drivetrain Electrolytic Frozen brake caliper rust removal project

[2002Targa]

Hey all,

thought I'd share a project I'm working on. First of all, let me try to describe exactly HOW frozen these calipers are and my goal. These things are SO stuck that driving the car, I spin the back tires on a gravel road just trying to turn the front wheels after pushing the brakes. Once I get going a bit, it it will gradually free up a bit, but I still can't get going without slipping the clutch. At this point, I'm fully expecting to buy a set of rebuilts, but if this works out, I'll be a happy camper.

I got the calipers off and tried to blow the pistons out with air, 185PSI and not one of them even budged. I tried getting a pair of channel locks in there and grabbing the lip of one of the pistons to try to turn it and NOTHING.

I'm not going to go into the mechanics of ERR, just google electrolytic rust removal and you'll find plenty of info and even a few videos. But here's a couple of links on it:

http://myweb.tiscali.co.uk/andyspatch/rust.htm

http://www.instructables.com/id/Electrolytic-Rust-Removal-aka-Magic/

Here's where a guy did a whole trailer:

http://antique-engines.com/trailer-electrolysis.htm

[2002Targa]

(nt)

[2002Targa]

I actually started this last night, I just couldn't wait any more to check them.

They're back in the tank now, hanging as you see in the last pic. I'll let them soak like this for a day and then flip them over and let them soak upside down for another day. From everything I've read, the magic is line of sight, I'm hoping that enough magic will happen between the pistons and the cylinders to free them up.

If not, I'll try rigging a piece of rebar as an anode coming directly up between the calipers and somehow mount them to a piece of wood or something.

Will repost again tomorrow night with results.

TK

[AlaskaMike]

Holy cow!

TK you should come up to Wasilla and help me dunk my 1974 Turkis 2002.

What did it do to the brake lines?

[AlaskaMike]

Wow seriously that trailer dunking is insane. Is a 1600 gallon electrified tank in your yard a liability? Now.. you could build a tank large enough to put HALF an '02 body in, and then raise it back up and lower the other side in...

[2002Targa]

(nt)

[Kidasters]

I was doubtful before - but you are having great results! Can't wait to see the finished product.

Ken

[AlaskaMike]

Yum! , that looks like a cappuccino with a nice froth.

I look forward to your final results.

[Kidasters]

If they are done with being in the bath - you might want to paint them with something to keep the rust away. If I remember right - the factory lines come with a coating on them.

If it were me, I would rustoleum....

Ken

[Guest Anonymous]

You say the charger is as old as the hills, it looks like maybe you ought to dunk that too! I am curious though, if you upped the amperage with a larger capacity charger, would it speed up the process? How much is too much? Would a 6volt charger take twice as long as a 12Volt'er?

Its not clear to me whether you left the pistons in or not. Since they are the wearing surface, and they are typically chromed or polished, I would think it was not necessary to immerse them. Any issues with the brake lines and purging them of air?

Thanks

[bobthomas]

I haven't this yet on any really large parts. I've seen speculation that as long as the part is kept moist,perhaps covered with a cloth kept wet with electrolyte solution,this method would work for large parts. Seems a kiddie pool would be big enuff for lots of stuff. OP is correct. Line of sight is very important.

[Guest]

Read the caution on hydrogen embrittlement in the link shown. You might want to bake out parts before using??

[2002Targa]

Well, I'm making some progress. The first two pics are from pulling it out of the bath this morning. Unfortunately, all 8 pistons were still frozen in the cylinders. I spent the entire day hooking the calipers back up to the car/bleeding and pumping the pistons out. If anyone ever goes through this, use an old brake hose and put it between the fenderwall pipes on the passenger side to block that whole side off and just do both calipers on the drivers side. I didn't figger this out till the very end. Saves a lot of running back and forth.

Kidasters: Yup, it's all going to get a good coat of black rustoleum.

Ignacio: From everything I've read, long and slow is the process. Kind of like grilling a nice rack of ribs.

Turkis: I was reading that about the embrittlement. It's probably going to be a few weeks before the car is on the road. They'll sit on top of my hot water heater in the meantime.

[2002Targa]

Here's a couple shots of the Anode. I think that next time, I'll just make a full wraparound cage out of the expanded metal.

[zippy500]

I am really impressed with what you have done here, Its funny cos I just bought a small kit off good ol ebay, to do exactly the same with the brake calipers.

was the chrome on the pistons OK, cos it says that the kit will strip chrome

When I bought my 02, the calipers where given to me a bucket in pieces one off the calipers still has 2 of the pistons stuck in (diagonal).

Can someone tell me how the pistons are linked, do the pistons work on opposites of each or diagonal ?