This should really get the purists here all wound up…
The caps on my brake/clutch reservoirs have given up the ghost. After ~22 years, the VERY thin aluminum “screw” part of the caps has literally just about turned to dust, so they barely screw onto the bottles, and the whole plastic/aluminum float assemblies are no longer connected to the screw caps. Amazingly, the float assemblies and plastic parts appear to be just fine. But, given that the “correct” replacement bottles/caps available STILL seem to be quite expensive, and of marginal quality at best, I’m seriously thinking of forgoing originality, and replacing them with something far cheaper, far more functional, and more readily available. I came across these:
Being an old BMW guy, this has a certain attraction. This one bottle provides fluid for both brake masters, and the clutch master. It is baffled, so the two brake masters each have their own fluid reserve, and the clutch connection comes off nearer the top of the bottle, so, while a brake leak will starve the clutch, a clutch leak cannot put the brakes at risk. A single float switch covers all three systems.
Doesn’t matter, since the bottle and cap are a matched set.
I’ve ordered both, should be here later this week.
(Author of the Book, former owner of an '83 XJ-S H.E.)
Over on the XJ-S list, we’ve been replacing the OEM garbage remote reservoir with one from a Mitsubishi for years. There are actually two different Mitsubishi items that will work, one round and one rectangular. Either has a vastly superior level sensor involving a magnetic float, and either has a diaphragm over the fluid to keep moisture out. They have two outlets; the XJ-S has two reservoir connections on the brake master cylinder and no clutch.
The thing I’d worry about is mixing the fluid from my clutch with that from the brake circuits. The fluid in my clutch reservoir turns dark and eventually black over a period of months. The brake fluid does not. This phenomenon doesn’t appear unique to my car - you will find several references to it in the archives, and if you Google “black clutch fluid” you will get a large number of hits for a wide range of vehicles, whereas “black brake fluid” seems much less common. I have never experienced any downside to the black clutch fluid (I still replace it every 1-2 years), but I would be wary of having it mix with the fluid used to stop the car!
Happy to report I received the new reservoir and cap/float assembly today, and the quality appears to be really excellent. The plastic is very thick and strong, it is all beautifully made - FAR better than the Jag bottle ever were, and a fraction of the cost. The cap fits perfectly, screws tight, and seals perfectly. It even has a little rubber “button” on the cap you can push to force the float down, to test the light. This seems to me a perfect solution for those not overly concerned with originality.
I removed the old bottles yesterday, breaking two of the plastic nipples off in the process. Mounting these should be a piece of cake - the bottle has two slotted mounting holes. The only minor issue I see is the nipples are sized for a larger hose than the normal hard lines, but that should be easy enough to work around. It should mount with no irreversible mods, other than re-forming or replacing the hard lines to the master cylinders, and suitable new lines are available from any auto parts store around here.
I’ll post pictures once it’s mounted. I just designed a very simple milled mounting bracket, that let’s it mount to the heat shield using the existing bolts. If I get energetic, I’'ll get it fabricated later today.
The nipples are not a problem at all - they measure just about 5/16", so the standard 1/4" hose slips over them easily. The fit to the heat shield, and how it all lines up to the hard lines appears near-perfect, though I’m sure the hard lines on my car are not bent in quite the “factory” shape.