Way OT -- brake fluid

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I've got a 1952 MGTD. When I put her to bed last fall, the brakes were fine. Now the peddle goes down to the floor. First step is to add brake fluid, but I don't know what's in there now. Have seen plenty of cautions about mixing fluid types. Any way of figuring out what's in there now?
TIA
Larry
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Purge and replace.
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Robatoy wrote:

First of all, is it really low? If so, and it's only sat there over winter it's got enough of a leak need to find and fix it first.
That there's no pedal resistance indicates probably developed leak in master cylinder over the winter most likely problem imo.
Had early postwar (exact vintage unknown/lost in time but it had odd bits and pieces that indicated it was kinda' cobbled together very shortly after while production shortages were still a problem) TC.
Unfortunately had to sell it to keep living to get thru school... :(
--
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TD Driver wrote:

This means you probably have a leak, right? The problem with just adding fluid after a leak is that there is probably air in the lines. Air has a funny way of working its way through the line to cause a failure at an inopportune time, like when you want to stop. :-) That means you have to bleed the lines, anyway. If you're going to bleed the lines, you might as well find the leak and fix it. I'm assuming you want to keep that classic in shape. :-)
If the leak isn't apparent, I would say you could add the recommended fluid just to top it off so you can pressurize the system to find the leak. Evacuate all the fluid. Fix the leak. Refill with recommended fluid. Bleed the lines. Enjoy a drive.
--

-MIKE-

"Playing is not something I do at night, it's my function in life"
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DOT 3 and 4 *will* mix with water so take a little out of the master cylinder and add it to a container containing a little water and shake. If after sitting it separates then you have DOT 5.
DOT 5 is usually purple or blue while 3 & 4 are honey colored. Unfortunately they all turn a dark brown after a while.
You are correct, do not mix 3 or 4 with 5.
DO NOT spill DOT 3 on anything you like, it will either destroy paint or rust bare metal.
As was already said you most likely have a leak or a bad master cylinder. The seals in a master cylinder can go without showing a leak. Top off the fluid and *gently* pump the pedal to see if you get improvement. If you don't get improvement start looking for leaks. If it is one of the wheel cylinders (drum brakes) quite a bit of fluid can leak inside the drum before you can see any w/o removing the drum.
good luck.
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As was already said you most likely have a leak or a bad master cylinder. The seals in a master cylinder can go without showing a leak. Top off the fluid and *gently* pump the pedal to see if you get improvement.
A 'bypass' leak of the internal cups in the MC will cause the described symptoms. Instead of pressurizing the lines/cylinders it will simply cause the fluid to re-circulate within the MC.
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You can most often hear it squishing in there as well. The medical people would call that a bruit.
I don't know what the big deal is. in college I drove one of my Minis a week with just a parking brake till a part came in.
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Robatoy wrote:

I did that with my ugly MustangII.
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-MIKE-

"Playing is not something I do at night, it's my function in life"
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-MIKE- wrote:

until you pushed the button on the end of the lever. I miss that.
--
Gerald Ross
Cochran, GA
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Every one pretty much has given you good advise. But if the pedal goes to the floor now, adding fluid may not solve the problem if it is low. If you applied the brake pedal to a low MC you probably have air in the lines as previously mentioned.
Look under the car around the bottom of the tires and see if there is any fluid leak from a leaking wheel cylinder.
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TD Driver wrote:

25000 hits. One seems like a book you should have. Look at (Amazon.com product link shortened) . Might be of interest if a bit pricey (new at $46 and used at $93 (?)). I am a bit envious of you and your TD. Oh well.     mahalo,     jo4hn
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It is most likely DOT3 but I would advise flushing the complete brake system and replacing with fresh fluid.
If you want to determine whether it is glycerine based brake fluid (DOT3 & DOT 4) take some of the old fluid and see if water mixes with it; Silicone based fluids (DOT5) do not mix with water.
:wq
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with the average voter. (Winston Churchill)
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In the past 50+ years it may have been mixed or changed, at least. Good chance it is DOT3 or at least can take it. If the pedal goes to the floor after just sitting, most likely you have a bad seal or a brake line corroded through and the fluid should be flushed after the repair anyway.
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Thanks for all the good advice, guys. I'm a woodbutcher, not a mechanic, and the only time I spend with the MG is when I'm behind the wheel, not under the car. Bad form, I know, but I'd rather be making sawdust than tinkering with the car. I'm gonna take your advice and see if what's in the car mixes with water and then fill 'er up. I just want to run her out to the mechanic for a full brake inspection and let him get to the root of the problem.
TD Driver wrote:

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Keep in mind that 1952 cars did not have the dual master cylinders If you have a corroded line, you will have no brakes at all. I just replaced the line on one of my cars last Saturday and it is only 8 years old. If in doubt, call the truck with the hook.
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Edwin Pawlowski wrote:

sure that they have a name).
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Norvin wrote:

Tow dolly.
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Jack Novak
Buffalo, NY - USA
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Nova wrote: ...

What does Dolly say?
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Hello?
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dpb wrote:

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