When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
In the Bendix master cylinder (see photo) the forward most reserve of fluid slowly empties. I can't find a leak anywhere.
I don't know too much about these things.... could it be leaking into the Brake Booster? Do I have one??? Is it behind the firewall under the dash????!
How do I deal with this? Can I somehow shove a tube and suck out the fluid collecting in the Brake Booster that is hiding in he dash? Is this a thing? These manual breaks.
You have manual brakes with no booster. If by forward resevoir, you mean the one on the front, closest to the radiator, start pulling brake drums for you have a wheel cylinder leaking or a leaking brake line.
If you mean the reservoir at the firewall side, look inside where the pedal rod enters the firewall and check for leaks and fresh brake fluid. If none is present, do as earlier, check wheel cylinders leaking by pulling brake drums and trace all brake lines, including the rubber lines to each front wheel and to the rear axle from the hard line from the frame.
So for 3 years I have had the same thing happening on my 69 Camper Special , but it does have power brakes . Happens when it sets for a long time . In that 3 years I have never found a leak - Had the brake drums off - never leaking under the truck - just disapears ! You can fill it up - drive it around - check it when you get back and it never looses a drop . But after it sets a while it will be low again . ??? So I hope someone has a solution .
Think about it!! Where can the fluid go? Well its either leaking into the inside of the firewall or down thru the lines or out the wheel cylinders, could be the brake shoes are soaking it up if its just a small amount at a time. The only way to find if the wheel cylinders are leaking is to pull it apart.Do you have a firewall mat or carpet? Pull them back and look for signs of fluid.... it's going some where.
Another one here!! I have the same problem with my '69 F-350. If the truck is parked for a length of time, the front reservoir empties. I've looked and looked and cannot find a leak anywhere. There is usually a tell-tale sign somewhere, like fluid leaking down on the inside of the tires or in back of the Master Cylinder as mentioned, but there is always nothing. The only thing I haven't done yet is to pull the Front Drums, but being a Wrecker just used for Yard Work, I just keep filling it as well as bleeding the brakes when necessary. Strange though, this last time and for the first time since the problem first started, it only emptied half way. It must be sealing itself up somewhere.
Yup. Exactly what the other owners said here. If I'm using it, never leaks. But if it sits for a long time, unused, the front reservoir empties right out.
All drum breaks, I haven't pulled them apart yet, but I've otherwise looked and looked. Still no sign of fluid.
The fluid is most likely inside the truck. The only other option is the park it inside with cardboard under the truck and wait to see where the leak is. If it's not in the master cylinder it is in the drums, on the ground on under your floor mat. Those are the only three options!
2X most likely inside the truck. But also check around the brake distribution block. Which looks like a proportioning valve. It is mounted to the left frame rail under the firewall.
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
Break fluid disapears!
