Brake fluid bottle & cap

[Colin McA]

Hi guys,

What is the fix for a rust fluid bottle cap? Is there an alternative or is it just find a better second hand one?

Mine has a jubilee clip round it which I don't like much. The bottle is a metal one.

Colin

[Warwick (Ozcoupe)]

I have the same problem on a newly acquired car. The float is still functional but it just hangs through the remains of the metal screw-cap. Air, moisture and dust can get in. Not good.
I've temporarliy solved the problem by removing the float and old cap and using the cap off a can of paint stripper. (It was on hand and almost empty).

I would expect they are probably the same in the UK. It's from those 500mL through to 4-litre or 1 gallon cans of everything from paint thinners to methylated spirits. Usually has a red plastic cap with a child-proof function that requires you to press down when opening. They have the same thread as the reservoir, since it too is essentially just a can.

If you carefully use side-cutters or wire cutters to snip the edge of the plastic cover, it can be broken up and removed leaving a tin-plated steel screw cap.
Use an awl or tiny drill bit to put a small hole through the metal cap without puncturing the plastic or cardboard washer/seal underneath. Then use a needle to put a very small hole in that seal from beneath, but not opposite the other hole. This will allow the reservoir to breathe enough to stop a vacuum forming.

That will keep it clean and reasonably moisture-free until you can either get a new cap or use another can cap to fit the float through.

I haven't got to this stage yet. It will be tricky cutting a large neat hole in such a thin piece of steel. But it might be possible to find a suitable all-plastic cap with the same thread.

[stantondavies]

Replacements are available but there are alternatives. There is plenty of information in previous posts if you search.

[harvey]

Personally I like the look of the later plastic reservoir and cap which was fitted to the P6 as well.

[Phil Nottingham]

Its fitted to other cars too like Land Rovers and I think its safer as larger see through capacity. If the bean can type must be kept that can loose its meagre fluid through pinhole corrosion, then many plastic caps with floats of all sorts of cars actually fit quite well.

[Colin McA]

So the p5b and the p6 has the same plastic bottle?

I will probably have one of these. I must say that I was never happy with the rubber hose to the master cylinder. My p6 (2200tc) had a weaping hose and there was a mysterious fluid loss.

Cheers
Colin

[Phil Nottingham]

The tin bean can reservoir was a standard Girling item on many cars from the early 30's It was on all hydraulic braked with or without level cap Rovers until approx 1970 when the plastic version was fitted, this superceded the tin can on many other cars from that date as well.

The rubber hose does loose its grip when it ages - it has just done so on my Land Rover but then that's 34 years old!

This means the level cap version was used on late P4's, all P5's and quite a few P5B's

[Welsh Warlock]

There is a plastic cap that will fit the metal master ctlinder. I picked one up at the NEC a few years ago which I used until I bought the cast version from Scott's Old Auto Rubber in Austrailia. Expensive but VERY good quality and worth it.

[Ken Nelson]

I also bought a cast brake cap replacement from Scott's Old Rubber in Australia and it was excellent quality and worked well. My cork float had turned into an anchor, so I fashioned a new one from a wine cork. Seems to work well, and the wine wasn't bad either. Ken

[Allan NZ P5b]

I also have a cast brake cap replacement from Scott's Old Rubber in Australia and it is excellent quality and worked well. My cork float had also turned into an anchor, so I did the same as ken all works fine now. Last time I checked Scott's no longer did the cast caps.
Just looked now and can't see it on his web site any more. might be worth an email to check if you are interested though. I do have a later plastic reservoir and cap which was fitted to the P6 as well, in case I need it in the future.

Regards