Brake Line Question

[Russell J]

1972 F100 manual brakes...
I’ve been having an issue when I’m at a red light, I can feel the brake pedal slooooowly drop as I’m holding it down. I’ve inspected my brake lines and can’t seem to locate the issue. The odd thing is that when I check the master cylinder every now and again, there doesn't seem to be a loss of brake fluid?? If anything, the smaller reservoir is just a tad low.

I’m considering replacing a section of front brake line but this particular line has what appears to be coiling around it? It runs between the frame and the steering gear box. Is this some sort of special brake line since it has the coiling? What’s the coiling for? Can I replace with standard brake line? If not, where can I find ONLY that section without buying the whole line replacement kit?

Thank you!!

[hillcountryflt]

Coiling of the brake line is used to absorb the vibrations between the cab mounted components and the frame mounted brake distributor. The cab is attached to the frame with rubber dampners to absorb vibrations. You can create a reasonable coil by using a can, say soda size, and wrap your line around that two or three times.
Brake lines are tedious to make, but I was pleasantly surprised at the fact that none of mine leaked after replacing all brake lines on my 71 after converting from front drums to power discs. You need a flaring tool with the adapter for double flaring, the ability to read instructions or follow you tube videos and some/lot of patience.
The smaller reservoir supports your rear brakes (or it should, unless some previous owner mixed things up).
Have you tried bleeding your brake lines - starting at the passenger side rear wheel, then driver's side rear wheel, then passenger side front finishing with the wheel closest to your MC.

[tnlprt]

The spiral coiling around the brake line is to protect from abrasion

Not really needed

[ultraranger]

If your MC initially holds pressure but after a few seconds the pedal starts sinking towards the floor, you have a bad MC and need to replace it.

The fluid is leaking back through the compensating port(s) in the bottom of the fluid reservoir(s). Instead of the MC building pressure throughout the brake system and holding it, the fluid is leaking through the compensating port and right back into the reservoir. This is why you don't find any fluid leaking from the system.

[AZf100]

[Russell J]

Nice! Thanks for the responses folks!!!!

[Russell J]

...and Holy Cow! Master Cylinders range from $130 for new to $30 for Cardone remanufactured...

Suggestions anyone?

[ultraranger]

...and Holy Cow! Master Cylinders range from $130 for new to $30 for Cardone remanufactured...

Suggestions anyone?

Rebuilt MCs generally have a high failure rate. If you like changing rebuilt MCs every 6 months to a year, buy remanufactured. If you'd like the MC to have a better chance of lasting for several years of service, get the new one.

Brakes are the most important system of any other system on a vehicle. For me, I don't buy rebuilt MCs. I think my life, and my family's lives, are worth spending $130 bucks on, for a critical vehicle component.

What MC are you looking at and from where?

I have a (brand new) 'modern' MC on my truck and it was under $90.00 dollars. ....it wasn't a direct bolt-on (metric bubble flare ports) but, I'm just sayin'.



My old conventional cast iron MC the modern MC replaced.

[Russell J]

OK, my NEW Wagner master cylinder came in the mail just now. I'm familiar (via YouTube videos) on the process of bench bleeding. But my questions is this...
The new master cylinder came with two different length "push rods" that I assume attach to the brake pedal arm. One is short, one is long. I have manual brakes.
Question....should I replace my push rod with one of these new ones? No directions came in the box.
Thanks!