Author Topic: Master cylinder restoration  (Read 5455 times)

Gambitt

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Master cylinder restoration
« on: February 23, 2009, 02:28:10 PM »
What is the best method to keep the master cylinder looking good?  I have heard that even powder coating doesn't hold up well.  What methods has everyone used and what seems to be holding up well over an extended period of years?

Jerry@CHP

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Re: Master cylinder restoration
« Reply #1 on: February 23, 2009, 03:08:06 PM »
Cast blast or #1613 Krylon, powder coating loses the patina of the casting.  Don't do that.

Jerry

Gambitt

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Re: Master cylinder restoration
« Reply #2 on: February 23, 2009, 10:23:17 PM »
Do either of these hold up?  It seems almost impossible many times to not get a little bit of brake fluid on the outside of the master cylinder.  I've been told not to use silicon brake fluid by several people I know that are very solid mechanics.

fireZ

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Re: Master cylinder restoration
« Reply #3 on: February 24, 2009, 01:58:58 AM »
Are they black or cast? Thanks  ???
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LIC # RPO Z28

RamAirDave

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Re: Master cylinder restoration
« Reply #4 on: February 24, 2009, 05:20:28 AM »
Are they black or cast? Thanks  ???

Ive seen them restored both ways.  From what Ive read, they were painted with a low-quality black that didn't last too long.
"Build them how the designers and engineers envisioned them to be"

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Pex68

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Re: Master cylinder restoration
« Reply #5 on: February 24, 2009, 12:41:10 PM »
Do either of these hold up?  It seems almost impossible many times to not get a little bit of brake fluid on the outside of the master cylinder.  I've been told not to use silicon brake fluid by several people I know that are very solid mechanics.

Nothing will really hold up for long with glycol based fluid.  Early formulations of silicone had a tendency to swell/soften rubber hoses/seals-that issue is long gone and a lot of us use it in our cars with no problems.  Only issue is putting it a system that has had glycol in it, they just don't mix well (at all) and any remnants will cause issues (sludge), best used in a fresh/new system with a pre-flush of the restored master on the bench.  Entrained air can also be an issue in silicone fluid but once it's gone it's gone.
See this also:  http://www.camaros.org/forum/index.php?topic=4945.0

Chris P
1968 Sequoia Green SS 396/325 M20

Gambitt

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Re: Master cylinder restoration
« Reply #6 on: February 24, 2009, 01:09:19 PM »
Maybe it was the earlier formulations that was used.  My system will be completely new, so I wouldn't have to worry about the sludge problem. 

Pex68

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Re: Master cylinder restoration
« Reply #7 on: February 24, 2009, 05:50:59 PM »
Maybe it was the earlier formulations that was used.  My system will be completely new, so I wouldn't have to worry about the sludge problem. 

Just remember to thoroughly flush the master on the bench as their usually assembled with glycol fluid and be sure to let the fresh silicon fluid sit in the master over night after bench bleeding, or replace it with fresh, so your not filling the system with air entrained silicon fluid.  Also bleed more than normal at wheel cylinders/calipers to flush them also.  I may be exaggerating the point, but it is harder to get air out of the system with silicon fluid if youíre not careful with itÖanother reason why every day mechanics donít like it! (I used to be one)  Do it right and you'll never have any problems with it!

Gambitt

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Re: Master cylinder restoration
« Reply #8 on: February 24, 2009, 08:16:34 PM »
Thanks for the tips.  I will probably go with the silicon after hearing all of the postive remarks.  It doesn't look like silicon is a perfect solution, but I guess it is the best there is for classic cars for now.

JohnZ

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Re: Master cylinder restoration
« Reply #9 on: February 24, 2009, 08:24:03 PM »
Note: It's siliCONE, not siliCON - siliCON is sand.  :)
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Pex68

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Re: Master cylinder restoration
« Reply #10 on: February 24, 2009, 09:46:36 PM »
Note: It's siliCONE, not siliCON - siliCON is sand.  :)
Ha ha, I had it right in the eariler posts!  :o :-[  Thanks John! ;)

Gambitt

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Re: Master cylinder restoration
« Reply #11 on: February 25, 2009, 04:17:07 AM »
I wondered that when I was spelling it earlier.  So what do you run in the green Z John?

Jerry@CHP

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Re: Master cylinder restoration
« Reply #12 on: February 25, 2009, 01:46:05 PM »
I would use the silicone fluid.  I have used it in all my race cars and show cars.  I've never had any problems.  And think of all the stopping I do at over 120 mph.
Jerry

JohnZ

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Re: Master cylinder restoration
« Reply #13 on: February 25, 2009, 05:26:26 PM »
I wondered that when I was spelling it earlier.  So what do you run in the green Z John?

Regular DOT4 fluid (Castrol LMA), and I change it every three years.

Jrschev

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Re: Master cylinder restoration
« Reply #14 on: February 27, 2009, 02:27:29 AM »
This may seem irrelevant but I use DOT 4 in my race bikes (motorcycles) and it works fine. DOT 5 (sliicone) is great so long as you can afford it and want to start fresh. The only reason for it's existence is because of the need for higher boiling points to meet the demands of modern braking systems. It was never intended to be used in the resto business even though it has worked out well in that regard. Half a dozen to one and six to the other. DOT 4 will never be a problem with taking on water if you live in the west (dry climate). If you live in the rain forest up here in NY the constant cycling of temperature causes excessive condensation and evaporation. This is where the water comes from in the brake fluid. Almost can't be avoided as the system is vented purposely. Throw in some heavy braking and more temperature cycling of the brake system and the problem is exagerated even further. I think in most of our old cars this is rarely a problem as they are stored nicely and not usually driven hard.

DOT 5 Silicone fluid does not enhance in any way the braking effectiveness of your system. It is a fluid and simply transfers motion. You could actually use water, oil, or even grapefruit juice to do the same job but it goes without saying the ancillary problems would be significant.

Anyone who has ever handled brake fluid noticed the unique texture and feel of this fluid. It's the glycol (basically sugar) that gives it this property. At the same time it's also why it is soluble in water. Not much different from conventional anti freeze. This is where it gets it's raised vapor point from. A double edged sword.

Silicone is synthetic (man made) from chemicals that are not organic. This is where it gets it's rasied vapor point as well. Keep in mind also that the violet color is a dye added to the fluid to identify it to the observer so that you do not add conventional fluid to a silicone system.

Just my ramblings for the evening.
1969 Z11 Pace Car (05A) 350/300 L48 4-Speed

MRPENNYPKR

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Re: Master cylinder restoration
« Reply #15 on: February 27, 2009, 02:43:00 AM »
Just my 2 cents.   I have used silicone in several restorations over the past 10 years with excellent results, and would highly recommend it for all installations (with proper precautions for glycol conversions).  The satisfaction of wiping up a spill from the inner fender and not removing all of the paint canít be beat!  Why risk it?

1968RSZ28

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Re: Master cylinder restoration
« Reply #16 on: February 27, 2009, 02:49:37 AM »
DOT 5 Silicone fluid does not enhance in any way the braking effectiveness of your system. It is a fluid and simply transfers motion. You could actually use water, oil, or even grapefruit juice to do the same job but it goes without saying the ancillary problems would be significant.

Trust me, you don't want to use grapefruit juice.  The pulp causes havoc in the brake system!     :D

Paul

Gambitt

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Re: Master cylinder restoration
« Reply #17 on: February 27, 2009, 02:57:08 AM »
So living in Kentucky and keeping my car in and insulated garage...would I be okay with silicone brake fluid.  This thread has been very informative:)

Jrschev

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Re: Master cylinder restoration
« Reply #18 on: February 27, 2009, 12:42:41 PM »
DOT 5 Silicone fluid does not enhance in any way the braking effectiveness of your system. It is a fluid and simply transfers motion. You could actually use water, oil, or even grapefruit juice to do the same job but it goes without saying the ancillary problems would be significant.

Trust me, you don't want to use grapefruit juice.  The pulp causes havoc in the brake system!     :D

Paul

Oh, no problem. Go to the market and get the "without pulp" type juice. It costs more but then you won't have the pulp plugging everything.

Your car would be fine with Silicone living in the Blue Grass state or any state for that matter. Go for it!