Topic: Caliper emergency! Please calm my nerves...

[ddanz27]

Okay so I picked up a caliper seal tonight for my 350f and wanted to start the rebuilding process on my caliper (hoping I can get by with just a seal and no new piston). I get it off okay and everything looks fine only I can not get the piston or pad out of the left hand side! How do I get this thing out so I can continue?? If it is frozen in there am I going to have to drop a couple hundred on a whole new caliper??? Like always, thanks for your help guys...

[BeSeeingYou]

I take it you disconnected it from the master cylinder?  Hook it back up but don't mount it to the fork, bleed it and use the master cylinder to pump the piston out.

[cameron]

everyone does that the first time.

[scottly]

If you can't pump it out with the master cylinder, the grease-gun method never fails.

[ddanz27]

Yes I did disconnect it from the MC. So I should be able to reconnect and just pump it all the way till it practically falls out? Thanks that makes sense now, looks like I just got ahead of myself. Heres another question for ya, what kind of medium should I polish/clean the cylinder/piston with? steel wool to rough?

[cameron]

hook it back up, bleed it a little.. and use the hydraulics to pop it out. CAREFULLY, or you get covered with fluid.

And fine sttel wool is fine.. but probably overkill. Hopefully it will come out pretty clean, with no surface rust or anything.
Last time I did mine.. i used a paper towel and some windex.

[BeSeeingYou]

Yeah you will have to bleed it to get it to work.  You don't have to do a perfect job.  A cloth and polishing/rubbing compound will do the trick on the piston.  Make sure you clean out the seal groove as junk collects in there and causes the brake pad to hang up.  

And make use of the search function as all this has been posted before as well as just about every other problem you may run into.  A wealth of useful advice is at your keyboard.

[faux fiddy]

I just did a thread on that/ question and advide from an old school  GURU.

Use a softer metal to dig the crud out of the groove the seal sits in.

Homemade tool made of copper, a softer metal won't scratch things up.

http://forums.sohc4.net/index.php?topic=84409.0

And as far as nerves, if beers don't work, maybe hunt down a valium?

Oh yeah, and I hear DO  NOT USE WD-40, DO NOT USE SOLVENT, DO NOT USE PENETRATING OIL. USE ONLY BRAKE FLUID AND DISC BRAKE ASSEMBLY LUBRICANT.

\ Anything else ruins brake seals.

+1 to all of the above.

[Kong]

You might be able to clean up your piston, once your get it out, with steel wool, but what you may find is a rusted ring around it right where the old seal contacted.  Stock replacements are irrationally expensive but a member here crafts composite replacements (using stock Ford (Lincoln) caliper pistons as his base stock) that will last a lifetime.  He charges about half what a stock replacement costs and his pistons are superior.

The best way I've found to clean the caliper itself it to toss it into a can of carb cleaner overnight.  Do that and you won't have to scrape the (aluminum) seal groove with anything harsher than an old tooth brush.

[MoMo]

You might be able to clean up your piston, once your get it out, with steel wool, but what you may find is a rusted ring around it right where the old seal contacted.  Stock replacements are irrationally expensive but a member here crafts composite replacements (using stock Ford (Lincoln) caliper pistons as his base stock) that will last a lifetime.  He charges about half what a stock replacement costs and his pistons are superior.

The best way I've found to clean the caliper itself it to toss it into a can of carb cleaner overnight.  Do that and you won't have to scrape the (aluminum) seal groove with anything harsher than an old tooth brush.

Kong,  does the carb cleaner damage the black finish?...Larry

[Kong]

Larry,

Didn't touch mine.  The caliper cases are apparently powder-coated. 

I'll come back later today and note which brand of carb cleaner I used on them - it was probably the "Gunk" brand, but I'll check.  Whatever it is the stuff was sold at Advanced Auto, I'm sure of that; I bought a gallon of it ($19 if I remember correctly) just a couple of months ago.

[bollingball]

+1 on all others advice. Only if you have to use steel wool use #0000

[ddanz27]

Thanks for all the advice guys. I ended up just reattaching the mc and pumping thr piston out that way. Once I got it out though I noticed some pitting on the piston. Were talking ballpoint pin sized pits. Should I try and reuse or buy a new phenolic?

[BeSeeingYou]

If you are the neat type you can clean them with a sharp pick then fill them with JB Weld using a plastic squeegee made from a milk jug.  Sand smooth with very fine sandpaper if needed.  If you're the type that tend to get more on you that the object being repaired get the plastic replacement.