930 caliper recon - what to use for cleaning, and then lubricating on reassembly -JW?

[dickster]

i have my 930 calipers stripped to the bare bones, and pistons removed.

i have the rebuild article thanks to "Thom" which states alcohol should be used to clean them, without lint cloth, and a caliper rebuild paste used on reassembly.

but i wonder what you guys are using?

i guess this applies to any caliper rebuild - what are your techniques for this operation?? i want to weigh up my options.

don't wanna waste a good drop of alcohol unless really necessary! (i wouldn't know where to get hold of this stuff).

any tips appreciated

[ttweed]

Denatured alcohol is readily available here in any grocery store as "Rubbing Alcohol" and it's cheap. I use 3M nylon scrubbing pads with it to take off any residue on the pistons and cylinders and then reassemble with synthetic caliper lube like Permatex Ultra Disc Caliper Lube.
HTH,
TT

[dickster]

thanks tom,

i read in another thread that someone had used steel wool - seemed a bit TOO abbrasive to me!!

[AirCooledExcellence]

allright dickster!!??

When I rebuilt mine last year I used steel wool, works great, just make sure you get a very fine grade.

Have a good weekend!

Cheers,

Tim.
____________
1983 SC Targa

[dickster]

aahh tim hi,

how are you?

did you use alcohol?

have a good weekend yourself

[Mike Feinstein]

I used plain-old brake cleaner spray, a scotch-brite pad, and some "Sil-lube" (as recommended in Wayne's article on caliper rebuilds) from the local Napa store. Worked great.

I'd be tempted to avoid steel wool for fear of leaving tiny steel bits in the bore which could damage your new seals.

[AirCooledExcellence]

dickster,

Like Mike, I used brake cleaner as well (about 2 cans!). Breath enough of it in and you'll be high for the rest of the day! (or end up in hospital)

Cheers,

Tim.
____________
1983 SC Targa

[Superman]

A can of alcohol is a must in any respectable garage. It is one of the few solvents that leave no residue and I use it all the time, particularly as a final rinse. Nevertheless, I squirt brake parts with brake cleaner as a final rinse. Brake cleaner also leaves no residue, and the cans push out a fairly strong spray.

Another thing I keep in my garage is very very fine sandpaper. I've got some 2000-grit stuff that is so fine it feels like bunny fir. That's what I used to clean (polish, really) the tiny bit of rust I found on my pistons.

I have always used brake fluid as assembly lube for calipers, but they tell me silicon grease is at least as good or better. I'll use that next time.

Whatever you use, alcohol or brake cleaner, the parts must be absolutely completely clean and free of particles, lint, residue, everything.

[AirCooledExcellence]

Originally posted by Superman
I've got some 2000-grit stuff that is so fine it feels like bunny fir. That's what I used to clean (polish, really) the tiny bit of rust I found on my pistons.

Supes, You've felt some funny bunnies then!

Cheers,

Tim.
____________
1983 SC Targa

[arcsine]

Denatured alcohol and rubbing alcohol are not the same things. Denatured alcohol is ethanol (what we normally think of as alcohol) diluted with something to make it undrinkable (kerosene or jet fuel often times). The ethanol content is ususlly 95%. Rubbing alcohol is isopropanol diluted with water. The isopropanol content in rubbing alcohol if I remember correctly is around 15-20%.

Having said that, either one will work as a solvent to remove gunk from a caliper and be relatively safe for the user.

[dickster]

as always, thanks guys

[911nut]

Scotchbrite pads are an excellent subsitute for steel wool.

[Emission]

This sounds crazy, but I re-built my 930 calipers about a month ago and used a different approach to cleaning the calipers. They were covered in grime/dust so I called a Porsche nut and asked him. On his suggestion...

I filled a large bucket with hot water and laundry detergent (stronger - more lifting agents - than dish detergent). I mixed it really well then dropped both calipers into the mixture. Hours later, they emerged pretty clean. I used an old toothbrush to get off any other residue then rinsed them with lots of clean, fresh water. I dried them with towels and them put them under lamps to speed the process.

The detergent didn't harm the painted surface, rinsed off easily (as it is designed to do), and didn't leave any residue. Best of all, it was safe (non-flammable), and non-toxic (like brake cleaner).

I'd do it again in a second.

P.S. - I used Permatex Ultra Disc Caliper Lube during reassembly.

[Superman]

Aircooled, perhaps the thread is gone forever, but once Leland told a story about how he scared a bunny to death, and then someone else told a hilarious story about a dead rabbit that was bathed and dried and returned to its hutch. They didn't want the owner to know that her dog had killed it (an assumption of theirs). The owner returned and wondered why anyone would dig up a properly buried pet, bathe it and put it back in a hutch. I wish I could've found that and posted the link.

[dickster]

emission

i suppose you tend to worry about corrosion, but its alloy and if you dry it off properly it will be fine i guess. i'll use air on mine to dry them.

i've got some real strong detergent for my m/bike (off roaders use it) that i may try your method with. its completely safe to use on just about anything.

and it takes most of the work out of it which has to be a bonus

i'll give it a go.............

[Bill Verburg]

Don't use ss pads, they leave tiny bits of steel behind which lodges everywhere, PIA to get rid of it all.

[diverdan]

Nix on the steel wool! I learned the hard way! Way too much trouble to get it all off and dang, should you get water involved, the rust process is instant! Lots of streaks of that tiny rust steel dust!. The water is fine without the complication of steel wool. Yes, on the Scotch Brite! Brilliant stuff.

Diverdan