Brumby brake peddle moves 70% before brakes bite

YouTube · Post by **El_Freddo** » Mon May 19, 2008 11:49 am

Hey guys,

Sunnie the brumby is on the road. One problem I really want to iron out ASAP is that the brake peddle still moves too far down before the brakes work - probabily near 70% peddle movement til the brakes start biting properly. If you pump once they bite where you would expect them to - somewhere near 30% peddle movement.

We've bled the brakes, got a little bit of air outta the rear but still no change. When you use the brakes you can feel where it should bite but it keeps going further - it feels like there's something there thats just starting to pressurise up then it lets go and you end up at the 70% mark.

The brakes work really well, its just the peddle movement that i'm not happy with. Could this be the master cylinder needing an overhaul or the booster?
Can an L series master cylinder and brake booster replace a MY setup? - I've got a parts car at home that has all these bits and it would be the easiest option atm.

Crossbred kit is not an option - $$$ we don't have for a standard EA81

Any info welcome.

Cheers

Bennie

AndrewT · Post by **AndrewT** » Mon May 19, 2008 12:42 pm

Check that the one-way valve in the vacuum line off your brake booster is working properly (I think you probably have one on a Brumby??).
The booster itself could need replacing. I'm not sure how to test one other than swapping it for a known good one.
The is most likely more air in the system. Sometimes there can be an airlock in the master cylinder. You can sometimes fix this by taking it off and manually pooring fluid into the bore and refitting. Sometimes Subaru's require a LOT of bleeding before all the air comes out.
I believe an L series booster and master cylinder can be a replacement. In fact I also believe a few people have upgraded to Liberty units with relative ease (Subarino and Matatak for instance)

steptoe · Post by **steptoe** » Mon May 19, 2008 12:59 pm

and of course you have bled in the correct criss cross sequence ??

Matatak · Post by **Matatak** » Mon May 19, 2008 6:44 pm

El_Freddo wrote: If you pump once they bite where you would expect them to - somewhere near 30% peddle movement.

Any info welcome.

Cheers

Bennie

Sounds like air to me.

AlpineRaven · Post by **AlpineRaven** » Mon May 19, 2008 7:38 pm

Could be three things I could tell you -

Air in the lines that is "stuck" inside the joints
Master Cylinder on its way out
Calipers on its way as well

Cheers
Tristan

EDIT: check if the lines are rusty or not?

YouTube · Post by **El_Freddo** » Tue Nov 08, 2011 4:43 pm

While looking for another thread I came across this old dig ^

Thought I might update what I found and what was done.

Basically the rear brake shoes were completely worn out and no one had adjusted them.

Since Ruby Scoo had the rear discs I shoved her old self adjusting shoe setup, including the backing plate onto the rear of Sunnie the Brumby. After bleeding and some adjusting Sunnie the Brumby is stopping awesome now!

I should probably look at the rear shoe's meat as I remember them being low when I put them on...

Cheers

Bennie

Wagonman · Post by **Wagonman** » Wed Nov 09, 2011 11:16 pm

Even though you've fixed the problem. I'll throw in what I've found. Like Andrew T said Subarus can be a pain the bum to bleed properly. I've had 3 l series do it to me now. Bled them from the master cylinder etc properly and still a crappy pedal. Even threw another master cylinder on and adjusted the rear shoes still no change. I ended up clamping all the lines and getting a ripper hard pedal and took them off one by one after bleeding through and it seemed to work..

rubisubi · Post by **rubisubi** » Thu Nov 10, 2011 10:17 am

Id bet its your rear brake cylinders, 40 bucks each, mine got so bad the brake pedal was nearly to the floor. Any water or mud and they soak them in quite easily, a weak design and quite poor considering it should be suitable for 4wdriving.

YouTube · Post by **El_Freddo** » Thu Nov 10, 2011 9:38 pm

rubisubi wrote:Id bet its your rear brake cylinders, 40 bucks each, mine got so bad the brake pedal was nearly to the floor. Any water or mud and they soak them in quite easily, a weak design and quite poor considering it should be suitable for 4wdriving.

So you didn't read the whole thread then or my latest update?

Job's done, the rear drums were replaced with a set from the L series that are self-adjusting. They go really well compared to what they used to be!

Cheers

Bennie