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Brake fluid?

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RickB

RickB

Yoda
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I'm planning on bleeding the brake and clutch on my Mk2 Sprite this weekend.

When I went to the auto parts place I found lots of DOT 3 synthetic. Is that going to work well in my old system?
 
Always a hot topic!

My choice is Castrol GT/LMA - pretty much what they came with.
 
I've used the same as Mickey. Castrol CT/LMA
 
I'm racing with the DOT 3 / 4 sythetic. Mostly due to conveniece. Works fine and easy to get.

Any DOT 3, 4 or 5.1 fluid (marked "sythetic" or otherwise) is fine in your car. They will all mix easily.

The Castrol LMA is good stuff and meets the same DOT 3 / 4 specs (it has a slightly higher boiling point than most fluids and is supposed to absorb moisture less quickly).

The important thing is <span style="text-decoration: underline">NOT</span> to mix DOT 5 (silicone) fluid with any of the others. You should only use silicon brake fluid after a total flushing of your system.

One slight problem is that some folks mix up <span style="text-decoration: underline">DOT 5.1</span> fluid with <span style="text-decoration: underline">DOT 5</span> fluid.
 
DOT 3 here too. I put a speed bleed type nipple in my slave last time. It made bleeding SO MUCH easier. I got the right one off the shelf at Advance Auto for $8 for 2. (same as front brake calipers) SB3824, 3/8" 24 thread as I recall.

Here's the thread on it.
 
So for my 64 Sprite they should be 3/8 x 24 for clutch and brake bleeders?
That sounds like it would really beat the pants off of having a helper push down... up... (repeat xx times)...
 
Yes, front brake and clutch slave 3/8 24, on mine: rear cylinder 1/4 24 (but they're not original rear cylinders, this is what Jim wrote in that other thread:

Speed bleeder sizes:
Clutch (all spridgets) 3/8 x 24
Disc brakes 3/8 x 24 front drum brakes 3/8 x 24
Rear brakes (1 piston 1/4 leaf springs) 3/8 x 24
Rear brakes (2 piston wheel cylinder, semi eliptical leaf springs) 1/4 x 28
 
Well I haven't looked at my rear cylinders yet so I don't know what size they take.
I bought the 3/8 x 24 bleeders, at least one will fit in the clutch if not anywhere else. So with two only I'm thinking one goes in the clutch and one goes in the right rear and then I just bleed the other brakes as normal?
 
Someone who owned the car before me used some sort of DOT3 or DOT4 that sucked up a bunch of water and rust pitted my master cylinder. After a dangerously large diameter hone job, I'm running the Castrol DOT4 LMA stuff and it's not leaking.

I'll be bleeding the brakes once a year to fight the water issues. It doesn't take too long. I did it tonight in an hour including the clutch.
 
Dot 3 fluid of 30 years ago absolutly DESTROYED british brake systems. I'm still leary of anything but Dot4 LMA or complete system flush and Dot 5.
 
Just for reference, I would recommend that all of you look at the brake fluid cap on your master cylinder.

The cap on all three of my Brit-roadsters ('69 MGB, '73 Midget, '78 Midget) says "Use DOT 3 fluid".

All glycol-based fluids (DOT 3, 4, 5.1 or Castrol LMA) will absorb moisture over time....that's usually what causes the problems.

Just saying...... :wink:
 
I use DOT 4 only, drained and flushed every two yrs. Brakes are hard and firm...
 
Well why I opened my mouth and swallowed my foot by getting in on this topic I can't say!! When a young pup and fooling around with a great deal more brit cars than now it always seemed that when someone with hoses swollen shut and master cylinder cups swollen till they covered the bleed back holes had been using good ol american dot 3 fluid. Maybe we were wrong, not saying otherwise. I now use nothing but dot 5 in a completely flushed system. Ever heard of Lockheed Crimson? My first brit car called for that.
Any way, thats my story and I'm sticking to it!
KA
 
nomad said:
Well why I opened my mouth and swallowed my foot by getting in on this topic I can't say!! When a young pup and fooling around with a great deal more brit cars than now it always seemed that when someone with hoses swollen shut and master cylinder cups swollen till they covered the bleed back holes had been using good ol american dot 3 fluid. Maybe we were wrong, not saying otherwise. I now use nothing but dot 5 in a completely flushed system. Ever heard of Lockheed Crimson? My first brit car called for that.
Any way, thats my story and I'm sticking to it!
KA
Click to expand...

Well, now, I'm old enough and and an Englishman, and Girling was Crimson and Lockheed was clear, back then,and despite the maker's claims, they were indistinguishable. That was proved when independents came on the market selling brake fluid for either type!
 
You're right, it was Girling, and now I know my mind must be going!! But thats what a TC was suppose to get, right Roger. Can you back me up on dot3?
KA
 
Found a sealed metal can of Castrol LMA among the things the PO sent along with the car. Consider the question answered. :wink:
 
Don't mean to introduce trouble where it may not exist, but a metal can? Do you have any idea about how old that might be? Like Nial (aeronca65t) said, "Just saying..."

When was the last time Castrol put their brake fluid in metal containers? Sealed or not, I'm not sure I'd use it...

Just saying...

Mickey
 
mmm... fresh & clean Castrol LMA in a sealed can...

The question is moot now that it's in there.

No matter what I'm sure it is better than what's been sitting in the lines for years.

NOW - I wanna talk to whoever had the great idea on that clutch slave bleeder location!!!! You have to be kidding me right???

I think I lucked out, the line was flexing visibly when my kid would push on the clutch pedal so I looked at the connecting pin and it seemed pushed back.
I tapped it and pushed the slave back in and then the kid pressed down & up and the clutch slave cup went in & out. I think it was just stuck there from too much time sitting.

Ok - I know I'm engaged in some wishful thinking but hey it could be OK right?

I guess the next thing is to charge up the battery & get some gas in there!
 
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