Brake master. Cylinder rebuild kit
06-05-2016, 10:49 PM
#2
Team Owner
I know I didnt answer your question
However in the time it takes to mess with old parts you could be finished and not have to figure out why you just pumped 2 cans of fluid through the fresh rebuild and the pedal still feels spongy.
I would not bother rebuilding a brake master cylinder.
NOTE these are made to not be easily taken apart without damaging other parts of the system.
NOTE buy a new ATE cylinder and a fresh liter of ATE Gold fluid and a set of stainless flex lines and restore the brakes to perfect condition.
Put DC 111 on the grommets so the feed bores will not rust.
your old cylinder will have rusted feed bores as well
However in the time it takes to mess with old parts you could be finished and not have to figure out why you just pumped 2 cans of fluid through the fresh rebuild and the pedal still feels spongy.
I would not bother rebuilding a brake master cylinder.
NOTE these are made to not be easily taken apart without damaging other parts of the system.
NOTE buy a new ATE cylinder and a fresh liter of ATE Gold fluid and a set of stainless flex lines and restore the brakes to perfect condition.
Put DC 111 on the grommets so the feed bores will not rust.
your old cylinder will have rusted feed bores as well
06-06-2016, 12:54 AM
#4
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I just looked a brake line write up. I thought you had to replace everything from the master cylinder when doing the lines. It turns out you just replace the ones from the metal lines to the calipers.
06-06-2016, 09:36 AM
#5
Team Owner
yes its the flexible stainless steel lines that are replaced,
they reduce line swell so a firmer pedal is the result.
Roger has them as well
Dow Corning 111 get it on Amazon along with the deoxit 100
DC 111 is a non setting silicone lubricant it will prevent water ingress and preserve rubber when used at the grommet to MC bore feeder ports
they reduce line swell so a firmer pedal is the result.
Roger has them as well
Dow Corning 111 get it on Amazon along with the deoxit 100
DC 111 is a non setting silicone lubricant it will prevent water ingress and preserve rubber when used at the grommet to MC bore feeder ports
06-06-2016, 11:00 AM
#6
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I have the brake line kits for $85.
I have never seen a Master Cylinder rebuild kit for the later MC. Care to share what you are using?
87 & 89 use the same MC.
I have never seen a Master Cylinder rebuild kit for the later MC. Care to share what you are using?
87 & 89 use the same MC.
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission?
George Layton March 2014928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
06-06-2016, 01:19 PM
#7
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When you get the MC apart, you'll see that the pistons include some interesting check-valves that cannot be restored. So unless your kit includes full-assembled piston sections, it's not going to be complete. I've tried stretching new rubber bits on to similar ATE pistons, and end up scratching the piston in the process and damaging those very thin metal reed-valve style check valves.
Bottom line: not worth the risk of failure trying to rebuild these yourself. You can easily damage the check-valve sections, and not know it until you have a single-system failure. Then, the sign of failure is pedal-to-the-floor and the sickening thud and screech of bending metal. Replace with New as Stan recommends. Follow ATE's procedure for bench-bleeding the new MC before installation.
If you decide to replace the rubber brakeline sections with new, take precautions to keep the system full of fluid as you work. Fill the reservoir and put a tight double layer of Saran Wrap under the MC cap so no air will get in while the lines are open. Else risk air migrating into the ABS unit and other local "high spots" in the hydraulic system, and the challenge of getting it out.
Bottom line: not worth the risk of failure trying to rebuild these yourself. You can easily damage the check-valve sections, and not know it until you have a single-system failure. Then, the sign of failure is pedal-to-the-floor and the sickening thud and screech of bending metal. Replace with New as Stan recommends. Follow ATE's procedure for bench-bleeding the new MC before installation.
If you decide to replace the rubber brakeline sections with new, take precautions to keep the system full of fluid as you work. Fill the reservoir and put a tight double layer of Saran Wrap under the MC cap so no air will get in while the lines are open. Else risk air migrating into the ABS unit and other local "high spots" in the hydraulic system, and the challenge of getting it out.