No brakes

[maton_acoustic]

I've changed my brake hoses all around and a few lines. New master cylinder and I've bled the system 3 times and I can't get any brake pedal pressure what so ever. I didn't bench bleed the cylinder because I couldn't get a bench bleeding kit here so I did it on the car. I did both reservoirs at the same time probably around 100 pedal pumps each time. No visible air what so ever left including at each wheel. Am I doing something wrong or missing something obvious here?

Thanks

[Zed Head]

Not sure what changing hoses and lines all around means, but did the brakes work before? Is it a factory stock system or modified? No pressure even with pumping or the pedal goes straight to the floor every pump? You've given not much at all to work with.

Check the orientation of the bleeder screws on the front calipers.

[EuroDat]

Did you try bleeding the master cylinder at the side bleeders? The piping comes out at the bottom of the cylinder and air can still get trapped in the top section.

I always start there and then go to the wheel cylinders and calipers.

Chas

[maton_acoustic]

I took tubes from the side bleed nipples on the master cylinder straight back into the reservoir. Pedal travel decreased after the rear brakes were bled. I take it that it can only be air in the master cylinder if none of the brakes are being applied?

I changed 4 hoses plus the lines going into the hoses because the nuts were badly corroded.

Factory stock system and they did work before

Edited November 2, 2013 by maton_acoustic

[Zed Head]

Z brakes are generally hard to bleed. What method are you using? Do you have someone helping, one in the seat and one at the bleed screw?

I installed speed bleed screws on my rear cylinders so that I could easily push a lot of fluid through the lines. I've also developed a one-man system using a broken shovel handle on the brake pedal. But using vacuum at the wheels, or pressure at the MC reservoir would probably be easier. It can take a lot of time and brake fluid to get it done. Eurodat's implication is right, you need to start with a good methodical step-by-step plan and get each step right. One bad step can allow air back in.

And your car looks modified. Even though they worked before, if you have one of the brake "upgrades" on the front or back, that will add a lot of difficulty to the bleeding (ha ha, that's a UK double entendre pun) process.

[black gold man]

Rear shoe adjustment is very important . Cylinder will overextend and pedal will feel soft.

[maton_acoustic]

Ok thanks. I think I'm going to have to invest in a vacuum pump.

[nsanow]

I chased a problem like this in my 12/70 240z. I changed everything. Ended up being a bad brake booster. Didn't make sense since I literally had new everything from lines, calipers, drums, etc. That fixed the problem. My issue was no pressure and then brakes would grab at the last second before the pedal hit the floor.

[EuroDat]

Zed Head is right saying Z's are hard to bleed. Comparing it to the Escorts and Holdens I had. It also took a while to get it back to what it was before I rebuilt the brakes.

Sounds like you have changed a lot of stuff in the brake system and air pockets can be a right bugger to get rid of. A vacuum system will make it easier for sure, but that air lock in the master cylinder might still be a problem.

Using pressure on the master cylinder is something I nether thought of:stupid:.

Thanks for that Zed. I dont have a vacuum bleeder. Ill try that next time.

Black gold man's point is also one to check. The rear brake can be simplyy adjusted by using the hand brake. Every time you pull it it will adjust the rear shoes. Some people prefer to do it by hand but the factory manual says use the hand brake.

Thats what so good about this forum, your always leaning something new:)

Chas

Edited November 3, 2013 by EuroDat

[black gold man]

[malibud]

i had a brake shoe in the back **** eyed and could never get my brakes to work maybe worth a check