'Sweating' brake fluid reservoir

[mrtask]

Probably this has only to do with disuse, i.e. my not having finished my project and begun driving it yet. Be that as it may, what is for certain is that my fluid level has dropped whilst the car has been standing dormant. It glistens around the lowest 'ridge' of the white plastic Lockheed bottle, and beads on the new hose down into the master cylinder, where the silver paint is bubbling. The hose clamp(s) is(are) tight, I don't want to further tighten the top one for fear of crushing the out spout from the reservoir. Can brake fluid creep upwards against gravity? Or could there perhaps be a hairline crack in the reservoir, that I for the life of me cannot locate? Any helpful hints would be most gratefully appreciated.
Are the fluid reservoirs available new? Dosh waiting, who's got one for me?

 

[Tor]

Hi Al,

Moisture on the outside of the reservoir and beading on the feed hose can be unrelated, as they were on my car. The hose was the easy fix - replaced for one that is brake fluid capable, not just fuel line. 6mm (inner diam) hose fits snugly on the MC inlet and clamps nicely around the reservoir exit nipple. The reservoir is harder, as it's not fully airtight due to the design of the level warning sender. It has however got better with use, no idea how except maybe that it dried up from engine heat.

 

[colnerov]

Hi, change the hose, it has degraded and gone porous. Use oil or silicon hose.
Resevoir is probably OK.

Colin

 

[j_radcliffe]

How humid is the air where you are this time of year. If the air temp raises quickly and the dew point raises quickly, due to warm moist air moving in suddenly, there can be a thermal lag with the brake fluid temp. If the brake fluid temp is below the dew point of the air temp, then the reservoir will sweat with moisture from the air. I would have thought that this should stop pretty fast within a day or so though as the brake fluid temp should equilibrate to the air temp.

A good brake specialist should have some fluid resistant hose. I replaced mine about 5 years ago. Since I only needed 3 inches or so, they did not ever worry about charging me for it.

The reservoirs do come up on ebay from time to time. You might want to see if you can find a brand of dot 3 brake fluid which is colored. Then you will know if you have a hairline crack.


James.