[vintagemilano]

very good point about cleaning out the calipers if you use the grease method, so splitting the calipers, new square cut O rings required etc.
The bolt heads are "ribe" head...best use a ribe tool or you will mangle them, and they are nigh on impossible to find
(of course you can use something else)

Do you happen to know what size ribe is needed?

 

[alfaloco]

I've never used a grease gun for this procedure, because by the time you guys get finished cleaning up all the grease out of the drilled passages and bores of your calipers, I can have new seals installed, calipers back together and brake pads in place.
Good grief Charlie Brown! Grease has its place, but it's a mess to clean up. 😁😁

 

[Gubi]

Yeah, that's kinda my take. Also if the caliper's gotten to the point where grease is the only way to get the piston out then you should probably just replace the caliper at that point.

 

[spiderserie4]

Do you happen to know what size ribe is needed?

presuming front and rear have the same size bolt heads, then
Ribe is 'R5' in this good rebuild thread by PMB

https://www.alfabb.com/threads/restoring-some-105-115-rear-calipers.145700/

and confirmed here as well:

https://www.alfabb.com/threads/brake-caliper-bolts.197237/?post_id=8837553#post-8837553

 

[Gubi]

The first time I took a set apart a long while ago I didn't realize they were ribe head and used my impact driver with a Torx bit, lol. They must be really good bolts because the R&R went without any damage, but I would definitely not recommend doing what I did

 

[andylarry]

Even with the added labor, sometimes rebuilding the originals yourself is better than purchasing (perhaps) poor quality rblts online.

 

[goats]

Very Important Pro Tip. When removing the caliper RIBE bolts, do NOT turn the ribe end. Loosen via holding the RIBE end steady with the correct RIBE bit (for a while there, front and rear were different sized but I think Alfa eventually went to a single size) and only turn/ loosen the NUT. Use Kroil or other favorite liquid wrench type stuff as well.

 

[Gubi]

Very Important Pro Tip. When removing the caliper RIBE bolts, do NOT turn the ribe end. Loosen via holding the RIBE end steady with the correct RIBE bit (for a while there, front and rear were different sized but I think Alfa eventually went to a single size) and only turn/ loosen the NUT. Use Kroil or other favorite liquid wrench type stuff as well.

Okay, so that's another thing I don't think I did

Any reason why? Normally it shouldn't really matter.

 

[goats]

Normally -- and always -- it matters. Removing the nut itself needs to overcome only the friction / bonding forces of the nut against the thread. Turning the bolt head has to overcome the same forces, PLUS the forces imposed by any corrosive bonding to the body of material that the bolt passes through. Always easier to remove just the nut from any precision fit / corroded / potentially seized assembly when possible. Another PRO TIP. You're welcome!

 

[andylarry]

^^Agree

 

[PSk]

Grease gun method works but is a mess to clean up

Which is hardly a big deal compared to ruining a caliper piston by trying to grab hold of it physically. Just drop the calipers in to kerosene, and you should be washing them anyway.

And please can we stop the "must not split the caliper bollocks". Every brake caliper rebuilder just splits the calipers. There is the world's most simple seal in between the caliper halves.


This thread is an example of where the internet is NOT the best place to get advice. A mechanic will have used a grease gun, split and cleaned the caliper halves, put new seals in and assembled in no longer than 30 minutes for both calipers
Pete

 

[Gubi]

And please can we stop the "must not split the caliper bollocks". Every brake caliper rebuilder just splits the calipers. There is the world's most simple seal in between the caliper halves.

My guess is that's a holdover from when the internal seal was rather hard to find. I know I had a heck of a time getting some when I rebuilt my Milano calipers but that was like fifteen years back.

From a rebuilder standpoint (where they won't accept split calipers) I'd also guess some of that that stems from the fact that the fasteners are ribe, as you noted, and the rebuilders assume that the hoi polloi are going to mung them up if they try splitting them at home.

 

[PSk]

Amazing.

I'll stop talking as I cannot come up with anything constructive to say
Pete

 

[goats]

Which is hardly a big deal compared to ruining a caliper piston by trying to grab hold of it physically. Just drop the calipers in to kerosene, and you should be washing them anyway.

And please can we stop the "must not split the caliper bollocks". Every brake caliper rebuilder just splits the calipers. There is the world's most simple seal in between the caliper halves.


This thread is an example of where the internet is NOT the best place to get advice. A mechanic will have used a grease gun, split and cleaned the caliper halves, put new seals in and assembled in no longer than 30 minutes for both calipers
Pete

30 minutes for both calipers? Not a chance. Nowhere, no how for quality work. I'm a mechanic and I dont -- unless its court of last resort -- introduce grease into hydraulic lines and assemblies. I;ve had to clean that junk up and I dont wish it on anyone. Using air and a rag is my preferred method. And you do you. If you like the grease route go for it.

 

[Gubi]

Amazing.

I'll stop talking as I cannot come up with anything constructive to say
Pete

Who took the jam out of your donut, Pete?

If it was not clear: I agree that splitting calipers is perfectly fine, and was trying to hypothesize reasons why the "don't split calipers" advice had been provided. Centerline (or IAP? I don't remember) used to warn that they would not accept cores that had been split, for example.

 

[andylarry]

Time is different down under.
I never had a problem reusing the caliper half seals. Just keep them submerged in DOT 3 while they are removed.

 

[Gubi]

Yeah, I've reused them too. It's just that fortunately they seem to be more readily available now. Like Centerline has them, BK480.

I bought a set of rebuilt Milano rears like 15 years ago and they left one of those out Finding another one (at the time) took a bit of work.

 

[002]

I can also join in on the grease idea. I had a very stubborn caliper that was freed with grease. A bit messy to clean up afterward, but at least you don’t have to buy a new caliper…

 

[powerdoc]

On old, neglected caliper that have been static for years, I cut a brake line/or hose fitting, drill and tap it for a zerk (grease) fitting. Install it in the caliper and use a grease gun to hydraulically remove the stuck piston. This method is only need after lubing w/kroil and attempting to break the rust bond by working it in and rotating the piston with adjustable pliers as the grease technique makes a mess you must block the piston that frees up first to get the second to free up.

I've used this on my Norton Commando motorcycle; just have to clean out all the gunk in passages

 

[ADoherty]

Have any of you tried drilling a hole in the stuck piston and pull/prying it out? Right now I am stuck - cannot budge the piston to do a rebuild

All good advice so far on various ways to skin a cat. But note from my reading of the thread that it hasn't been mentioned yet that the piston may be slightly c0cked in the bore, and jammed enough to not come out. Generally it seems the reason pistons don't readily come out is either corrosion or being c0cked a bit. You may have a look and see (if youre caliper is off the car) if the piston looks unevenly seated in the bore. If so, 'persuading' it to even with a vice grip C-clamp, ping the piston with a hammer and piece of wood etc may free it up. Spray some kroil, lithium grease spray or something around the circumference first. Just rebuilt the calipers on my Spider in the Fall, and one of the fronts was a little jammed. They are a pretty tight fit in there, though can get c0cked. I think mine got c0cked from a cheap ebay pad spreader--the spreader wasn't pushing the pistons back evenly. Calipers had sat for a year, so were likely not moving that great to begin with. Good news is, the ATE rebuild kits are easy to find. Pretty rewarding job. Good luck