Outer Limits 4x4 Board

Help me out guys, I am not sure I've got my thinking right.

I swapped all four brake lines on a vehicle and screwed everything together, background is that the master cylinder has been sitting on a bench for maybe a year but the rest of the brake system had fluid in it. The brakes worked before but the booster was removed and rebuilt as they felt off and there was a hiss when you pressed the pedal.

Trying to bleed the brakes, first on a rear and then on a front, I couldn't get a drop of fluid at the wheel end. No movement in the reservoir level, nothing. This is with a vacuum type brake bleeder. Pressing the pedal I got bubbles and big burps in the reservoir but nothing else and no drop in fluid level.

Given that it's all steel brake lines except the new hoses the only thing I can think of is that the master cylinder has crapped itself from sitting on a bench dry..?

The other thing I tried was disconnecting the brake lines at the master cylinder and blanking off the holes with bolts. This made the pedal super hard, which then makes me think the master cylinder is okay.

I am just trying to think wtf could make brakes so unbleedable. It's not the vacuum kit because I bled a clutch with it yesterday no probs.

I wondered if it could be a leak somewhere else but the fact that front and rear act the same even though they are separate brake circuits makes me think that's wrong.

I will probably end up pulling the master cyl and getting it rebuilt but I feel like I might be missing something obvious.

did you bleedmaster cylinder first ? eg at the unions on the side of the cylinder , make sure you crack them and bleed all the air out of the cylinder before you try bleeding the brakes ..
can take a while to bleed after this if the long lines have been emptied .

micka1

micka1 wrote:did you bleedmaster cylinder first ? eg at the unions on the side of the cylinder , make sure you crack them and bleed all the air out of the cylinder before you try bleeding the brakes ..
can take a while to bleed after this if the long lines have been emptied .

micka1

Hmmm, sounds like something to try, thanks.

thats ok .

just try cracking each union at a time and bleed like normal , you'll notice air bubbles coming through .. just bleed till they stop then onto the next union .. once done try bleeding at the wheels .

should do the job ..if the cylinder is still ok

I hate it when I have something good to try and it's ten o'clock at night

If I were still single I'd be out there giving it a try right now, sadly it is no longer acceptable.

chimpboy wrote:I hate it when I have something good to try and it's ten o'clock at night

If I were still single I'd be out there giving it a try right now, sadly it is no longer acceptable.

Don't we all know that feeling!!!

micka1 wrote:can take a while to bleed after this if the long lines have been emptied .

Thanks, I think this was the only issue really. I did as you suggested and cracked open each joint to get fluid up to that joint, then got things happening at the brakes themselves. Took ages but it worked.

Then my vacuum bleeder thing broke, it's only two months old so I was a bit cut, but the vendor has said he'll send a replacement straight away. So for now I'll just leave the job half done , at least I am not stressing about it any more though.

dude get your self a length of clear hose the right diameter to fit on your nipples. crack bleed nipple and attach hose. put other end in bottle or up high. keep an eye on the level and sit back. when no air comes out tighten nipple and move onto the next wheel. hope this helps. ray