Tips on replacing/refreshing brake calipers?

[jhenard]

In addition to Larry's guidance - I did two sets of Spitfire calipers and it is fun to do. In the Triumph world you go to the 7th circle of hell if you split the calipers but you will be ok.

• I am a fan of new pistons if available
• I used a dremel and a brass wire wheel to clean up the bores
• I used red rubber grease in the bores and when repacking the seals
• Tape over the bores if you are going to media blast the calipers
• The piston popper tool saved me filling the recycle bin
• Now is a good time to change bleed valve and chase threads
• This is also a good time if you you are planning a change in brake fluid type if that is an issue (but that is another thread)

[2002]

If you need new pistons, caliper half seal rings, caliper bolts, or other caliper parts they are available at:

 

https://www.wallothnesch.com/en/bremse/bmw-1502-2002-turbo/katalogbild-34-03.html

[tdskip]

Good morning gentlemen, thanks for all of the reply’s and information.

 

i was able to get compressed air on these yesterday and the pistons all responded. The pistons on the same side as the hard lines where snappier but that is kind of expected due to them being closer to the source of air, right?

 

 

[halboyles]

On 7/1/2020 at 9:02 AM, jhenard said:

I used red rubber grease in the bores and when repacking the seals

Natural rubber because regular petroleum grease has the potential to eat at the seals.  Castrol makes a good one.

 

http://www.redrubbergrease.com/

[irdave]

Just to add for the next person, because your compressor goes to 90 or 120 doesn't mean you need to use all that pressure all the time.  Pressure regulators are great.

['76mintgrün'02]

Obligatory brake job recommendation--  These little four inch vise grips are really nice for loosening brake fittings.

Then you can finish the job with a flare wrench.

 

W&N would be a fun place to shop, if not for the cost of shipping. 

 

I bought two new pistons from Rock Auto for $9 each.

https://www.rockauto.com/en/moreinfo.php?pk=4558023&cc=1010822

 

They also sell the pins and clips

https://www.rockauto.com/en/moreinfo.php?pk=2027056&cc=1010822

 

and seal kits

https://www.rockauto.com/en/moreinfo.php?pk=2045640&cc=1010822

 

(I simply reused those parts, since they looked okay-ish).

My brakes were dragging up front, due to pistons not returning, due to rrrrust in the outer part of the bore(s).  I removed the rust and they return just fine now. 

 

Removing the stuck pistons was a challenge and I broke the end of one in the process.  (don't use hammers)  The other piston I replaced had some pitting through the chrome.  I don't see any reason to replace pistons that look okay.

 

In the end, I used the grease gun trick to push the stuck pistons out.  The fittings on my gun have the same threads as the flex lines in the brake system, so that made it easy to connect.  Grease does not compress like air, so there is not a POP when they finally come out and the grease simply fell out of the bore in a big plug, which made cleanup quite easy.

 

Do be careful using compressed air.  Mine POPPED out, making a cloud of vaporized brake fluid and I felt really crappy after breathing it in.  I should have left the shop to let that crap settle out.  Well, I should have used a bigger towel to catch the mist.

 

Tom

 

EDIT-  sorry for all the 'extra' information.  Glad you had such an easy time of it!

Edited July 2, 2020 by '76mintgrün'02

[tdskip]

3 minutes ago, '76mintgrün'02 said:

Obligatory brake job recommendation--  These little four inch vise grips are really nice for loosening brake fittings.

Then you can finish the job with a flare wrench.

 

W&N would be a fun place to shop, if not for the cost of shipping. 

 

I bought two new pistons from Rock Auto for $9 each.

https://www.rockauto.com/en/moreinfo.php?pk=4558023&cc=1010822

 

They also sell the pins and clips

https://www.rockauto.com/en/moreinfo.php?pk=2027056&cc=1010822

 

and seal kits

https://www.rockauto.com/en/moreinfo.php?pk=2045640&cc=1010822

 

(I simply reused those parts, since they looked okay-ish).

My brakes were dragging up front, due to pistons not returning, due to rrrrust in the outer part of the bore(s).  I removed the rust and they return just fine now. 

 

Removing the stuck pistons was a challenge and I broke the end of one in the process.  (don't use hammers)  The other piston I replaced had some pitting through the chrome.  I don't see any reason to replace pistons that look okay.

 

In the end, I used the grease gun trick to push the stuck pistons out.  The fittings on my gun have the same threads as the flex lines in the brake system, so that made it easy to connect.  Grease does not compress like air, so there is not a POP when they finally come out and the grease simply fell out of the bore in a big plug, which made cleanup quite easy.

 

Do be careful using compressed air.  Mine POPPED out, making a cloud of vaporized brake fluid and I felt really crappy after breathing it in.  I should have left the shop to let that crap settle out.  Well, I should have used a bigger towel to catch the mist.

 

Tom

 

EDIT-  sorry for all the 'extra' information.  Glad you had such an easy time of it!

 

 

Super info - no apology needed!

[AustrianVespaGuy]

A bicycle pump can also work nicely for popping out the pistons if you don't have an air compressor.  Also allows you to work them out more slowly/controlled than even regulated compressors, albeit with more elbow grease!

[tdskip]

For those of you that use grease to pop out the Pistons how do you clean everything after words to make sure there’s no contamination

['76mintgrün'02]

A combination of wiping/brake cleaner/compressed air.

[tdskip]

Got half the piatons out, easily. The others - not so much.

 

Ideas before splitting the calipers?

 

EDIT -  just noticed that the seal kit does not have the critical seal that goes between the calipers so definitely not gonna split these until I know that those are available and good quality. Oops.

 

EDIT #2 -  Block off the openings where the pistons have been removed and time to use grease? 

 

 Thanks!

Edited July 2, 2020 by tdskip
Clarity and because I’m a moron

[NYNick]

The pistons you removed have to be put back in to create an air seal for the other pistons to be pushed out. They're loose now anyway so they'll come back out after you pop the other ones out. 

 

You need to secure them with a C clamp or something so they don't pop out again while you're working on the other ones. Also, protect them from damage from the other ones popping out, with force, with a piece of wood.

 

I had to bang the calipers strategically with a BFH to get the stuck pistons to move. I also sprayed them with PB blaster and used a C clamp to see if they would push IN at all first, just to see if there was any movement. Once they budged, I knew I was going to get them out. A little out, a little in etc.

 

Good luck.  Nothing is easy anymore. I had 8 frozen pistons in the 911. EIGHT!

[tdskip]

32 minutes ago, NYNick said:

The pistons you removed have to be put back in to create an air seal for the other pistons to be pushed out. They're loose now anyway so they'll come back out after you pop the other ones out. 

 

You need to secure them with a C clamp or something so they don't pop out again while you're working on the other ones. Also, protect them from damage from the other ones popping out, with force, with a piece of wood.

 

I had to bang the calipers strategically with a BFH to get the stuck pistons to move. I also sprayed them with PB blaster and used a C clamp to see if they would push IN at all first, just to see if there was any movement. Once they budged, I knew I was going to get them out. A little out, a little in etc.

 

Good luck.  Nothing is easy anymore. I had 8 frozen pistons in the 911. EIGHT!

 

Thanks Nick - and ouch, sorry the 911 put up a fight.

[Conserv]

4 hours ago, irdave said:

Just to add for the next person, because your compressor goes to 90 or 120 doesn't mean you need to use all that pressure all the time.  Pressure regulators are great.

Like horsepower, Dave...

 

Just because your ‘02’s got 98 horses on tap, doesn’t mean you need to use them all.

 

Oh, wait, bad analogy there... ???

 

Best regards,

 

Steve

 

 

 

Edited July 2, 2020 by Conserv

[tdskip]

The Pistons are out. The C-clamp worked a treat.

 

Thanks  for the ideas and tips,  you all have been exceptionally supportive of my digging in to try to get this thing back on the road.