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I've been doing the bleeding the conventional way having a helper push in on the brake pedal. As for the master cylinder, I "bench bled" it on the car using the vacuum to pull the fluid through till there were no more bubbles.

What I think was happening on mine is because of the angle, air floated to the top while fluid dropped and was pushed out. I think an air pocket was still present near the piston. I had to almost turn the thing upside down and get the outlets on the upper side so air could exit.

I've little experience with automotive brakes, but on aircraft often the preferred method is to pump fluid up from the brakes to the reservoir, pushing the air out in reverse. Is that possible on car brake systems? We use a pressure pot, but you can do it with an oil can and a hose to the bleeder fitting at each brake.

If you're not able to get the pedal somewhat firm with a proper vacuum bleed, then there's a leak in the system. The system is closed from the master to the wheel cylinders, so for the pedal to go down, either fluid goes out or it's not completely full of (incompressible) fluid (i.e.air in = spongy usually). When pedal pressure is released, then back flow occurs as the springs release. So leaks in can happen on that part of the stroke as well.
Fluid can bypass the master back to the reservior and not be observed. If you're getting air leaking in, then you'll get water at some point. I'd look hard at those corroded areas and determine why. You may have to replace some parts to get a firm pedal as the fluid to metal seal can be compromised with pitting.

Hey Jim,

The two things I did that started this whole "fiasco" were: letting some fluid out of the passenger side rear wheel cylinder and, loosening the connection of the hard line to the rear brake hose because the rear hose was twisted. Once I did those things I bled the rear brakes to remove any air from the system. After doing those things is when I noticed the brakes had become soft.

So... Being that I replaced those leaky rear wheel cylinders with new ones; I think those can be ruled out. So then the question moves to the brake hose. Did I compromise its integrity by allowing it to be twisted? I will say this, I did notice a tiny bit of fluid around the connection between the hard line and hose a week or so ago. But that seemed to be fixed by tightening it up a little more.

This is one of the most perplexing problems I've had with this car. Should I try getting a new brake hose?

Thank you,

Should I try getting a new brake hose?


No, you should be getting 3 new brake hoses!! Never take a chance on a questionable or old hose, especially if it was kinked.

Hey guys,

Okay I'm very confused and at a loss. I've looked up the rear brake hose for my car at Napa, O'reilly, and Autozone. Each website has the length of the hose listed at 17.625" inches. However, the actual physical size of each of those hoses is 16.5" inches. WHAT GIVES!?!?!

The measurement of the hose I had on my car is over 17.5" inches; as the sites have indicated. The hose I have was supplied by Kanter. What part number's do you all have that work? I pulled the NAPA part number from the parts X-Ref.


Thank you,

An inch or so one way or the other makes no difference in the performance of the brakes as long as the hose doesn't bunch or get cramped with the suspension fully upwards, and is long enough to remain free and unstretched/unrestricted when the suspension is fully downwards.

Here are a couple photos of the rear brakes prior to any mileage; with the Raybestos wheel cylinders that I had to replace. Ross

-Garrett

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The only explanation that makes any sense to me is that, one way or another, a large amount of water got into the system. One the fluid reaches it's limit to absorb water (which isn't much), any remainder will form a separate component and since it's more dense that the brake fluid itself it will end up residing as a separate layer at the lowest portions of the system, the wheel cylinders and perhaps the lowest static portions of the master cylinder.