Brake System Rebuilding the brake calipers Written by the backyard hack mechanic Sean750 Document history: # 14 Jan 2004 added pictures of rear caliper rebuild kit # 13 Nov 2004 added more pictures while rebuilding other calipers, added different dust seal installation # 17 Jul 2003 added pictures of damaged brake pistons of the front calipers, rewrote some parts # 25 Jan 2003 initial version Problem : Of course you are preventing brake problems. You are changing your brake fluid every 2 year, and checking the dust covers of the pistons on a regular base. I don't, so I ended up with some problems. The last couple of months I wasn't satisfied about the braking power. I had the feeling I had to push the brake pedal a bit to strong to stop the car quickly enough. Like only the front brakes where working, but almost no braking power from the rear. After a long and fast travel across the European highways, I inspected the rear brake rotors visually through the spokes of the wheels. I expected a nice, shiny surface but it was still somewhat rusty. In other words, the rear brake calipers weren't doing their job very good. Time for a rebuild. Models : all. Background : These are pretty simple, straightforward single piston brake calipers. You have 4 of them. Where Mercedes-Benz is using double pistons per brake caliper for their S-series (W126), BMW is still using 1 piston and it does the job adequate, in case you have a small 7 (6 cilinder). The big 7 (12 cilinder) has simply to much weight for these calipers.....whe're talking about 1900 kilogram (4180 Lbs) of German steel.....as an '88 750 owner, I was never impressed with the brakepower of my car equipped with these single piston calipers. Fortunately, BMW got the same impression and changed the 750 front calipers to double piston calipers starting from modelyear 91->. But these calipers aren't mentioned in this story. The procedure shows the rebuild of the rear calipers, but the front calipers are exactly the same. Rebuilding a brake caliper doesn't mean stuff like machining or hone parts. Its simply a matter of thoroughly cleaning parts and replacing inner O-ring and dust cover. Therefore not a big deal. Looking at the photo's, this seems like a pretty extensive procedure. It isn't, and maybe for some Page 1 of 39 BMW 7-- Rebuilding the brake calipers 10/29/2011 http://bmwe32.masscom.net/sean750/caliper/RebuildBrakeCaliper.htm
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Brake SystemRebuilding the brake calipersWritten by the backyard hack mechanic Sean750Document history:
# 14 Jan 2004 added pictures of rear caliper rebuild kit# 13 Nov 2004 added more pictures while rebuilding other calipers, added different dust seal installation
# 17 Jul 2003 added pictures of damaged brake pistons of the front calipers, rewrote some parts
# 25 Jan 2003 initial version
Problem : Of course you are preventing brake problems. You are changing your brake fluid every
2 year, and checking the dust covers of the pistons on a regular base. I don't, so I ended up with
some problems. The last couple of months I wasn't satisfied about the braking power. I had the
feeling I had to push the brake pedal a bit to strong to stop the car quickly enough. Like only the
front brakes where working, but almost no braking power from the rear. After a long and fast
travel across the European highways, I inspected the rear brake rotors visually through the spokes
of the wheels. I expected a nice, shiny surface but it was still somewhat rusty. In other words, the
rear brake calipers weren't doing their job very good. Time for a rebuild.
Models : all.
Background : These are pretty simple, straightforward single piston brake calipers. You have 4 of
them. Where Mercedes-Benz is using double pistons per brake caliper for their S-series (W126),
BMW is still using 1 piston and it does the job adequate, in case you have a small 7 (6 cilinder).
The big 7 (12 cilinder) has simply to much weight for these calipers.....whe're talking about 1900
kilogram (4180 Lbs) of German steel.....as an '88 750 owner, I was never impressed with the
brakepower of my car equipped with these single piston calipers. Fortunately, BMW got the same
impression and changed the 750 front calipers to double piston calipers starting from modelyear
91->. But these calipers aren't mentioned in this story.
The procedure shows the rebuild of the rear calipers, but the front calipers are exactly the same.
Rebuilding a brake caliper doesn't mean stuff like machining or hone parts. Its simply a matter of
thoroughly cleaning parts and replacing inner O-ring and dust cover. Therefore not a big deal.
Looking at the photo's, this seems like a pretty extensive procedure. It isn't, and maybe for some
When installing, I managed to do a very stupid thing with a screwdriver and I damaged the new dust boot....$#@!!!. From that point, I wasn't in a very good mood because the parts seller was already closed. So I fixed the dust cover with some sealant:
Page 22 of 39BMW 7-- Rebuilding the brake calipers