mushy brakes -- I'm stumped

On my 95 Legacy wagon (front discs/rear drums) the brake pedal has a long travel and feels very mushy, though the car seems to stop OK. But even my wife, who generally notices nothing, thinks there's something wrong.

 

A couple of weeks ago, I bled the front brakes, figuring that if there were air bubbles in those circuits, that would account for most of the squishy feeling. No difference.

 

So I decided that the master cylinder was the probable culprit. Ordered a new one, which appears identical to the Japanese original (made in Japan, same number, same color cap, same Japanese printing).

 

Installed it after filling w/ fluid (DOT 3) and bench bleeding, then bled the entire system (front and rear) -- something that I've done dozens of times on different cars, including the Subaru. No improvement.

 

None of the lines or fittings are leaking. The front pads are fairly new. I pulled one rear brake drum for inspection, and while the brake shoes will need replacement soon, they're still OK. Brake pedal height and free play are good.

 

So ... I'm stumped.

 

One possibility is that the new m/c is defective. Another is that I really DIDN'T bleed the brakes properly. And a third, that I've heard of but never experienced, is that old rubber hoses can swell when pressure is applied, reducing the amount of pressure to the brakes.

 

All suggestions welcomed.

Sounds like you’ve been pretty thorough, but I would also pull the other drum and check it. Next you can adjust the rear brakes to where they barely rub the drums. The travel it takes to contact the drums could be causing that mushy feeling

I would recommend changing the Brake hoses to something more sturdy/stronger than the factory rubber hoses. You are most likely experience hose expansion, and changing over to a braided steel line will most likely help stiffen up the pedal a bunch.

I'd replace everything on the rear drums, or do a rear disc conversion. If they need replacing soon, and you are having travel issues, just do it now for peace of mind.

 

Also, i recommend stainless lines and a master cylinder brace. Those 2 really tightened up the pedal on my wagon

Thanks for feedback so far. A couple of questions:

 

--re master cylinder brace, can that be purchased or is it a DIY project?

 

--the car is a 1995 model. How long can I safely go before changing the original steel brake lines? (I've done this before on other vehicles, so I know the drill.) It's driven on heavily salted roads in the winter.

 

--the rear drums (or at least the one I pulled) appear to be in good shape, with no scoring, etc. Are they likely to be worn enough to account for long pedal travel and require replacing (vehicle has approx 95k miles -- documented)? Starting in '95, the rear drums became self-adjusting and on the side that I pulled, that mechanism appeared to be working fine. The clearance between shoes and drum was tight enough that the drum took some gentle persuasion to remove.

 

Thanks for the help!

Mushy brakes is also caused by the calipers - the vehicle has floating calipers and it's an indication that the guiding pins has to be taken out and re-lubricated since they have stuck on the caliper.

 

 

Also use DOT4 of 5.1 fluid. Never DOT 5.0. I don't know why people still uses DOT 3. I'm amazed that it's even available to purchase these days.

None of the lines or fittings are leaking.

 

Please double check this, especially around the hardline brackets. Keep the brake pressure up overnight (2x4 on the pedal against the seat or any other way) and check for leaks the next day.

 

--the car is a 1995 model. How long can I safely go before changing the original steel brake lines? (I've done this before on other vehicles, so I know the drill.) It's driven on heavily salted roads in the winter.

 

I don't know what it's like for '95s, but my 4th gen (2007) had hardline failure at 115k miles. I'm in the Northeast/New England.

My wife mentioned the same thing about my 99 Outback. I have the WRX brake upgrade on it, new rotors, carbon ceramic pads, H6 rear brake upgrade, new master cylinder, and I notice the same thing. I am going to be replacing the rubber lines with braided lines and installing a MC brace to see if it improves.