Bad to worse

[45acpJr]

Ok so I had a small leak on my driver side front brake hose, which I have been putting off. I took the truck to a detailer to have the engine and undercarriage steamed. After fighting water in the distributor cap and cauterizing my thumb on the headers I get on the road. Stop to fill up the tank, when I come back out my small brake leak is a bigger leak. I get it home, open up the hood to let it cool down faster and there is brake fluid underneath the hood and everywhere else. I'm assuming it just sprayed upwards from the hose, but my concern is it looked like it was leaking from the master cylinder resivoir also. What would cause that kind of pressure to make it do that if thats the case?

 

[str8axle55]

Put some fluid in it, and have someone pump the pedal while you look for the leak. Why would you put off fixing a leaking brake line?

 

[big dan]

Why would you put off fixing a leaking brake line?

x2That could get dangerous real quick.

 

[badmix]

x2That could get dangerous real quick.

X3...I wasnt going to say anything but since we have a dog pile going. lol.

I would say that is some screwy priorities, more concerned about clean motor than actually being able to stop. , too me, there is no such thing as a "little" brake fluid leak.

 

[Fordum]

Well, I don't guess I get to play. I have driven vehicles with single master cylinders with one line busted and hammered flat to keep it from leaking.

But in my defense, I was a lot younger, it was in the swamps, and if it blew loose I could always hit a small tree or drive off in the ditch to stop.

It was fairly common to snag a line on my old Jeep driving through heavy brush and lose all the fluid.
I would just slide under, hammer the broken line flat against the axle tube with a fold and then refill the master with the can I kept under the seat.

Sadly, I just remembered that I also drove it home that way a few times on the highway so I could replace the line in a dry area.
But, I was careful not to get in a situation where I had to depend on the brakes right that instant.
I would slow down way in advance and be ready to gear it down in a hurry if I had to.

Of course, my idiot cousin drove his Chevy all over town for 6 months with the right rear hammered because he forgot.
Remembered it just as he hit the building while parking........

And getting back to the original question, when you hit the brakes you develop hundreds to thousands of pounds of pressure, so with a small hole, it can spray anywhere. Just because you see it on a long way from the line does not mean a thing.

 

[45acpJr]

In my defense

The truck only gets driven maybe three times a week and probably only two miles at a time. Anyways.....the line has been replaced, but it still looks like I have some seepage from the cover of the master cylinder. The gasket was replaced already......suggestions?

 

[45acpJr]

And getting back to the original question, when you hit the brakes you develop hundreds to thousands of pounds of pressure, so with a small hole, it can spray anywhere. Just because you see it on a long way from the line does not mean a thing.

I understand the spraying from the broken line, I'm a little baffled from it leaking from the master cyclinder. I can see it on the side of the master cylinder and also the six little holes on the top where the gasket attaches

 

[Fordum]

Oh, OK, thats easy. You have an air bubble in the lines.
I see it a lot.

Turn the truck off, pump the brakes a couple of times to release all the boost.
Take the cover off the master. Have someone really stand on the brake pedal. Hold it for a couple of seconds then release it quickly.

There will be a geyser of brake fluid out of one or the other of the two chambers. That is the one with the air in the lines.

You can do it with the boost, but the geyser will be a lot bigger, and there is no need to get too messy.
Remember, on most of the masters, the front brakes come off the rear chamber, and vice versa.

What happens is, a system with no air does not move much fluid when pressed, plus there is very little movement back when the pressure is released. A set of drum brakes out of adjustment usually give the most return fluid. In that case, there will be a little spout of fluid, usually not enough to do much.
But, when you have a lot of air in the system, it compresses and when released causes the fluid spew back like a water hose.

Chances are its the side that had the bad line.

Of course, this will not work with the newer masters with only one hole, but they have caps that would not let the fluid leak out anyway, so I assume you have the older type.

 

[45acpJr]

Thanks for your input.....worked like a charm

 

[Fordum]

Glad to hear it. How high did it squirt? I had one hit a low ceiling one time when I had the booster on.
BIG bubble......