how to keep brake cylinders from rusting?

Question

ok, this really is metal related, right? I've got a car I'm parting out (an

87 porsche 944S if that matters to anyone) - and the brake master cylinder, and clutch master and slave cylinder are in good condition - If I just put them aside, they will be worthless in a year because the brake fluid is hydroscopic and I'll just have a corroded mess. I could pump a little DoT 5 fluid (a silicone oil) through them, but I'm not convinced that will really stop the corrosion because some of the dot 3/4 fluid may remain to cause trouble. I can disassemble, but then they will probably not work right upon reassembly (and kits are not generally available at a reasonable price).

There must be some reasonable way to protect these cylinders during storage - any suggestions?

Nick Mueller · Accepted Answer

Zip-bag with silica gel?Nick

Newshound · Answer

and flush them through with fresh fluid first?

Jim Chandler · Answer

You could try putting them in plastic bags or containers and drawing a vacuum on them. Maybe even put some dessicant bags in with them to absorb any moisture that might remain.Jim Chandler

Don Foreman · Answer

Flush with new fluid, then put in a container backfilled with argon from the TIG. Welding gas is very dry. Ziplock bags are better than nothing, but polyethylene is slightly permeable to water vapor. I like those cheap 1-gallon styrene or PET wide-jars with screw-top lids found at Wal-Mart.

Carl Byrns · Answer

Just about any plastic is permeable to water- that is why homebrewers use glass for lagering (slow fermentation).-Carl

Dave Hinz · Answer

On a related note, why can't we make functional copies of said cylindersout of stainless?  Is there a good reason the OEM parts aren't, otherthan the 27 cents each of cost savings?

Anthony · Answer

Dave Hinz  wrote innews:     The extra $5 each in machining costs.

William Noble · Answer

I have had some cylindes on one of my older cars sleeved with brass - by a company called "white post restorations" - good folks, by the way - they said that SS was too hard and would not form a good seal.  I've seen a service to sleeve older Corvette calipers with SS, but not drum brake cylinders or master cylinders.SS is also brittle sometimes, that may be part of the problem.

how to keep brake cylinders from rusting?

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