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disappearing brake fluid???

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mtlman8

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Hi all, so I drove the car a few days ago and had no trouble with anything. Tha car sat in the driveway for three days and got in and tried to drive to the store, but when I got to the end of the driveway I had a very low brake pedal.I opened the hood and checked the master cycinder and it was empty! I rebuilt the entire brake system about 4 months ago.I pulled all four wheels off and not a trace of fluid anywhere. no leaks under the car or at any line connection or bleeder valve. any ideas???
 
You don't happen to have a brake booster fitted, do you?
 
John, I don't know what you're driving, but if it's TR6 or TR8, Randall pretty much told you where the brake fluid is going.
 
TR3driver said:
You don't happen to have a brake booster fitted, do you?
Click to expand...

...that's where mine ended up!
 
John has a TR4A.

The fluid had to have gone somewhere so odd that you don't see any evidence. Did you pull the rear drums in addition to the wheels? Did you rebuild the original components and if so any signs of pitting especially in the master cylinder and rear wheel cylinders (More likely to fail than calipers)?

Scott
 
mtlman8 said:
Hi all, so I drove the car a few days ago and had no trouble with anything. Tha car sat in the driveway for three days and got in and tried to drive to the store, but when I got to the end of the driveway I had a very low brake pedal.I opened the hood and checked the master cycinder and it was empty! I rebuilt the entire brake system about 4 months ago.I pulled all four wheels off and not a trace of fluid anywhere. no leaks under the car or at any line connection or bleeder valve. any ideas???
Click to expand...
Some thoughts:
1. How far has the car been driven in the four months since the brake system rebuild?
2. When was the last time the fluid level was checked?

I'm wondering if perhaps the fluid was a bit low after all the rebuild and bleeding and such, and maybe it continued to drop as the front pads started to wear down...to the point where it emptied the reservoir. It's possible that there's no leak at all and that you might only need to top up and bleed and possibly check front pad wear and rear brake adjustment again (to be safe).

It doesn't seem all that likely, especially given the size of the reservoir on a TR4, but maybe....
 
Did you even fill it up? Not trying to be funny. It happens.
 
thanx for all the advise. I didn't pull the rear drums.yes i'm sure I filled it, because I used silicone dot5 at 26 dollars a quart.I like what andrew said and it makes sence.
 
mtlman8 said:
Hi all, so I drove the car a few days ago and had no trouble with anything. Tha car sat in the driveway for three days and got in and tried to drive to the store, but when I got to the end of the driveway I had a very low brake pedal.I opened the hood and checked the master cycinder and it was empty! I rebuilt the entire brake system about 4 months ago.I pulled all four wheels off and not a trace of fluid anywhere. no leaks under the car or at any line connection or bleeder valve. any ideas???
Click to expand...

John: In the future, when you report a problem, please tell us the model and year of your TR. You will get faster and more accurate replies that way!
 
I've found that if you refil the mc tank (I know, $26 a quart but it doesn't take a lot) and then stomp on the brakes a few times while in the drive or garage, the leak becomes obvious (at least in the absence of a booster). Tom
 
I scrubbed the driveway down and powerwashed, then I bled and refilled so after stomping on the brake a few times still no leak. maybe i'll see somthing in the morning. sorry frank I always forget. 1967 tr4a.
 
Whenever someone doesn't list what car a question refers to, I always look in their profile. If only one is listed, which is the case most times, I assume that's the car in question.
 
Just another 2 cents worth. When bleeding DOT 5, never get in a hurry! Never stomp the brakes or pump them fast while bleeding as silicone will get bubbles in it and give a false reading and later as the air works it's way to the MC, if it does, the volume might drop some. Just something else to look at. PJ
 
martx-5 said:
I assume
Click to expand...
And we all know what that does, right?
grin.gif


I did the same thing, but I believe a booster was optional on the 4A, and some folks have modified their cars; hence the question. And there are a few folks on here that work on cars not listed in their profiles.
 
So I can blame the wife! she is one who helped me bleed them the first time.This time I was very sure to tell her to depress the pedal slowly so I could look for air, I got a small amount of air out of the passenger side front, but still no leak and a nice tight pedal.
 
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