Brake service 87 M6

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Bhart
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Brake service 87 M6

Post by Bhart »

Finally getting around to servicing the brakes on my M6. I freed up the brakes enough (by working the pads !?!) to get my Mechanical fitness (yes, it's that easy in Ontario Canada) but it needs attention.

I'll post this in pictures and they tell a tale of little or no maintenance over 149,000 miles.
fortunately there were no stuck bolts or brake lines
fortunately there were no stuck bolts or brake lines
Rear start.jpg (266.82 KiB) Viewed 9260 times
pretty gooey with a burnt toffee smell.
pretty gooey with a burnt toffee smell.
rear sludge.jpg (299.8 KiB) Viewed 9260 times
Had to clamp them as they worked loose. Last one took 120psi of air to free itself from the caliper.
Had to clamp them as they worked loose. Last one took 120psi of air to free itself from the caliper.
4 stuck pistons.jpg (303.08 KiB) Viewed 9260 times
Attachments
plenty of crud
plenty of crud
Sticky piston.jpg (233.66 KiB) Viewed 9260 times
Last edited by Bhart on Mon Jul 10, 2017 7:32 pm, edited 1 time in total.
01/1987 M6

past Bimmers;
1970 2800CS
1988 325is
1985 325E
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Bhart
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Re: Brake service 87 M6

Post by Bhart »

One little tip - rather than pinching the hose closed with Vise Grips or other clamping device, I found these little caps at http://brakequip.com/.
BrakeQuip caps.jpg
BrakeQuip caps.jpg (160.07 KiB) Viewed 9259 times
Worked a treat and didn't leak for a whole week, while I fought with the calipers.
BrakeQuip cap.jpg
BrakeQuip cap.jpg (256.2 KiB) Viewed 9259 times
I did however replace the hoses but I will use the caps whenever I have to remove a caliper, rather than clamp.
old hoses.jpg
old hoses.jpg (312.94 KiB) Viewed 9259 times
01/1987 M6

past Bimmers;
1970 2800CS
1988 325is
1985 325E
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dwcains
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Re: Brake service 87 M6

Post by dwcains »

Tagged. I've got a set of SS lines I need to install on mine, so I'll learn from your progress. In.ce thread so far, Thanks.
Dean
Lutz, FL

'85 635 CSi Euro #9402254
'87 Spider Veloce
'92 Spider Veloce
'08 350Z

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jcburk
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Re: Brake service 87 M6

Post by jcburk »

I am just wrapping first stage of brake overhaul on my 87 M6 with similar miles. So stage 1 was rebuild front and rear calipers, new front pistons, new seals all around, SS brake lines and rotors. I just need to put the rebuilt caliper onto rear passenger side to wrap up. Stage 2 will be master cylinder and bomb. I have an excel file with parts, costs and links to websites if you are interested.
John,

1987 M6 the project
1999 323i it needed a home
2002 Honda Insight (technically my son's)
2014 Fusion basic transportation
2014 Cmax energi
2017 C43 AMG
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Bhart
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Re: Brake service 87 M6

Post by Bhart »

jcburk wrote:I am just wrapping first stage of brake overhaul on my 87 M6 with similar miles. So stage 1 was rebuild front and rear calipers, new front pistons, new seals all around, SS brake lines and rotors. I just need to put the rebuilt caliper onto rear passenger side to wrap up. Stage 2 will be master cylinder and bomb. I have an excel file with parts, costs and links to websites if you are interested.
- yes, I'd be interested in getting a copy of your excel file.

I have kept my pistons since they were all just superficially gunked up, no rust. The rotors are like new but with some corrosion on the non-contact area. I know the car sat for a few years and have no history on service. Once all that has been replaced and tested, I'll work on cosmetics. Booster line to master will be done when I remove the intakes for some new throttle shaft needle bearings.... along with coolant lines that hide under there, starter and anything else that will be hard to access.
01/1987 M6

past Bimmers;
1970 2800CS
1988 325is
1985 325E
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Bhart
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Re: Brake service 87 M6

Post by Bhart »

So, the bleeding was a more involved process than I thought. Got my assistant to pump 12 times between bleeds (had to show them the manual to prove I wasn't kidding) and I used almost 2 pints of DOT4 to get a nice clear stream and firm pedal. But the next morning, the pedal went down further so I had to convince my assistant to return and give it one more try. All 6 bleeders gave one final burp of air on the initial bleed and then were fine after that.

My years of working with computers have taught me patience to go back as many times as needed to sort an issue....... without getting (too) frustrated.

It's a nice clear day today so I'll go out and do some panic stops from speed.
01/1987 M6

past Bimmers;
1970 2800CS
1988 325is
1985 325E
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dwcains
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Re: Brake service 87 M6

Post by dwcains »

If you haven't used a pressure bleeder on the brakes, you're missing out on one of mankind's greatest inventions. Assuming the system hasn't been allowed to drain fully, I can do a bleed on all 4 calipers in just minutes, and I don't have to involve my "assistant". Typical fluid flush takes less than a pint, and because it's so easy I do it annually.

https://www.amazon.com/Motive-Products- ... B000Q6SL2W

One caution with this product, though. It seems the vinyl tubing it comes with it somewhat soluble in brake fluid (at least it is with the ATE Typ 200 or old Super Blue). I discovered this the hard way when the hose burst while I was bleeding my 350Z and brake fluid sprayed all over the left front fender. Luckily there was so much wax on the car I was able to quickly wipe off the fluid before any paint damage occurred. The tubing slowly turns a milky-gray color over time, and my method now is to just replace the tubing after every few uses - Home Depot/Lowes sell a 25-foot roll for just a few dollars, so it's not a big expense to be safe. Also, no need to pump the system up to a high pressure during a bleed. 5 to 7 psi is more than enough to move fluid through the lines, and at higher pressures I worry about blowing out the seals between the fluid reservoir and MC.
Dean
Lutz, FL

'85 635 CSi Euro #9402254
'87 Spider Veloce
'92 Spider Veloce
'08 350Z

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Bhart
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Re: Brake service 87 M6

Post by Bhart »

dwcains wrote:If you haven't used a pressure bleeder on the brakes, you're missing out on one of mankind's greatest inventions.
Yes, I have thought about this especially with the potential issues caused by draining the ABS if you don't keep the reservoir topped up. Seeing as how the second bleed has worked and no air effects are felt in the pedal, I'm set for the foreseeable future. Fortunately, my wife's still a good sport about pumping the brakes for these projects.
01/1987 M6

past Bimmers;
1970 2800CS
1988 325is
1985 325E
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Landsnark
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Location: Seattle, WA, USA

Re: Brake service 87 M6

Post by Landsnark »

Hi -

Just getting going with my 1987 M6 project, and I keep finding little clues about the car's past :D

Question about the brakes: Did these cars come with the 2 piece rotors, or was this a change someone made to mine? I know these are old... hat... now, but didn't think it was very common back in '87. Just curious.

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Bryan
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1987 M6
2009 128i
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jps635
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Re: Brake service 87 M6

Post by jps635 »

Pretty sure they will be custom made, and quite costly if making from scratch.

Might be hard to find replacement rotors. Any idea what they are? If you can find the same again, then I would stick with them (assuming no issues) as will be lighter and have better heat dissipation than stock.
'85 635csi JPS (RA2-66)
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Landsnark
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Re: Brake service 87 M6

Post by Landsnark »

I'm pretty sure this is a Frank Fahey upgrade, as I have a receipt that shows him charging a previous owner $650 for rotors and hats, circa 1994. They appear to be in good shape, I'm just curious if a) this is std equipment and b) if not, are they from another model BMW... :-k
Bryan
-----------------
1987 M6
2009 128i
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