They are clearly (from their condition) an aftermarket part. They don’t have the cork float, or alloy cylinder around it. Instead, the float consists of an inverted plastic tube which traps an air bubble as it is lowered into the fluid. At the top of the tube is a shaft which passes through a circular metal disk and then through a hole in the cap. Two contacts in the cap are connected by the disk if the float drops below the required level. It is similar in many ways to the cork float system, but the plastic is so light that the disk exerts very little pressure on the contacts when the float drops. As a result, the slightest build up of dry brake fluid on the edge of the disk is enough to prevent a circuit being made. Neither of mine worked until I thoroughly cleaned them, and I suspect that they will not work for long. Does anyone recognize them and their source, so I can avoid getting them if I order replacements?
I recommend you purchase a bottle of wine with an artificial cork, cut it in half, and you end up with two corks that will not deteriorate and will last forever. I did that some years ago, and they are still perfect!
Plus… the bottle of wine is a bonus!!!
LLoyd
“Prediction is very difficult, especially if it’s about the future.”
On my 3.8 the floats had sunk after being saturated with brake fluid. I was not sure if an artificial cork would disintegrate in brake fluid so I used a natural cork and coated it with marine epoxy. My fuel sender float had also been replaced with a wine cork which had sunk so I did the same there except I used a champagne cork for a little bit of class:). Both have worked well for years. This does not help David as his type of cover is a totally different design. Sorry but I I do mot know the source of your cover David.
Thanks Lloyd. That works fine with the original float system, with the cork float on the end of a piece of piano wire. Unfortunately, some PO (a teetotaler?) must have replaced that style with the plastic type shown in my photos. Before I opened them up, I was looking forward to being “forced” to buy a bottle of wine, but no such luck. Has anyone here bought new cap assemblies recently and received the good old type?
Yes, I bought a pair from SNG. They’re like the originals, though I’m not so curious about their floats to be inclined to take them apart. When the corks in my old caps saturated and sunk I replaced them with fresh wine bottle corks. Real corks made from the inner bark of the cork oak (Quercus suber). I don’t think it’s a good idea to use a plastic cork immersed in brake fluid, though Dot 5 might not affect the material.
The subject of the plastic corks came up years ago. I put some in brake fluid, nothing happened so I put them in reservoirs after the second set of real corks sank. No longer have the car but they were fine when I sold it and just spoke to the current owner yesterday, nothing has ever been said about the plastic corks sinking.
pauls
They were originally cork, likely for a reason. I’d be more concerned about junk leaching out of the plastic and messing up the brake fluid, given how the stuff attacks most organics, like paint f’rinstance. The first time I tried substituting heavy black rubber tubing under the reservoirs I learned about Dot3 compatibility issues - the hoses soon started to sweat fluid and black crud accumulated in the master and booster.
