Having found my PO had reversed the vacuum lines for the power brakes, I want to make sure the brake lines aren't reversed as well.

The master cylinder has two reservoirs for the brake fluid. A large one towards the front and a smaller one towards the rear. Currently the rear reservoir services the front brakes and the front reservoir the rear brakes.

Knowing that the front brakes provide most of the stopping power I want to make sure the PO did not reverse the brakes lines.

So, can someone please verify which reservoir services which brakes.

Thanks

 

Since disk brake calipers and even front wheel cylinders with front drums require more volume than rear wheel cylinders, the larger reservoir is always intended to feed the front brakes.

 

Based on that, I think it would be accurate to say that the PO was a certified moron because he as them ***-backwards!

 

Don't be too quick to pass judgement on the PO...most MCs that I have seen have the front brake section in the back (section closest to the firewall). As for the front brakes requiring "more volume"...there is no basis whatsoever for this statement. Maybe more pressure but definitely not more volume. If anything the rear brakes require more volume since the rear brakes are located farther away from the MC.
BTW - how do you reverse vacuum lines?

 

LOL, I assume he means the check valve was backwards?

It isn't that disc brakes "use" more fluid to apply them, it's that as the pads wear, more fluid is needed to make up for the pistons being further out. Hence they are "almost always" hooked up to the larger reservoir. The amount of fluid that flows to any brake during application is the volume needed to make the pistons move until there is pad/shoe contact, therefore has nothing to do with how far away they are from the M/C.

 

There is no "section closest to the firewall. It's a 51 F1. The brakes are under the floor.

The vacuum hose from the intake manifold was connected to the outlet side of the reserve tank. The line running to the power assist brakes was connected to the check valve, the inlet side of the tank. That's how you reverse the vacuum limes.

 

Without knowing that you have the power brakes in the stock location, we might assume you have hanging pedals, so the firewall reference is not out of line. So the section that would be closest to the firewall is the larger one, and that should be connected to the front brakes. I.e., your brakes are connected backwards.

 

I guess I missed the photo and the description of your vehicle, sorry. I guess I also missed the fact that a 51 Ford F1 came with a reserve vacuum tank, sorry again. My crystal ball has been acting up lately.

 

No basis? Seriously? On my truck, the two front caliper pistons are 3.1" in diameter and the rear wheel cylinder bore is only 15/16". As Ross mentioned, the idea here is to maintain an ample supply of fluid in the reservoir to account for brake lining wear. As the linings wear, the pistons in the calipers and wheel cylinders move farther out in their bores and the space behind them has to remain filled with fluid. It takes a much larger VOLUME of fluid in reserve to keep the disks up front supplied than the little 'ole wheel cylinders out back.

The distance between the master cylinder and the slave cylinders at the wheels has no bearing whatsoever on the volume requirements once the lines are bled. Assuming that the system stays sealed and the reservoirs don't run dry, the lines always stay full. The only volume that changes is that of the cylinders as the pistons travel through the bore. Basic hydraulics 101. Look it up.

I stand by my initial statement - because it is absolutely correct.