7 replies to this topic

[miller 666]

Just bled the brakes on my mini, all standard apart from some minifin drums on the back. Ive bled the system as ive just rebuilt the car and fuild was coming out but the brake pedal still goes straight to the floor. Its a servo system and i used to have a non servo system and i could just pump it up to get it firm. The pedal feels firm to push down but just goes to the floor. Haven't had a chance to test if theres any brakes at all yet. Is this normal?

[Surfbluegarage]

hhmmm strange.. 100% all nipples and linkages are tight? jack the car up at the back end and try pressing the brake while sumone spins the wheel.. if it doesnt do anything or very little.. adjust the back brakes as if youve fitted cheap minifins the castings arent brillinat nor are tollerences and could be too big... i.e shoes not going out far enuff to bind.... but saying this that shouldt cause the pedal to go to the floor especially on a servo aquipt system..
check your master cylinder aswell and make sure youve put the clevis pin in the pedal to master cylinder hahaha easy mistake..

[miller 666]

nope there the proper mini fins, the handbrake works alright. Will try jacking up there rear and see what we can sum up. Just seems a little weird.

[dklawson]

What else have you done with the brakes? New or rebuilt calipers perhaps? Are their bleed nipples pointed "up"? Have you fit new shoes under the Mini Fins? If so, did you put the shoes on in the right position? (Yes, there is an order).

The metal backing of the shoes will have a relieved area NOT covered by friction material at one end... and the friction material will go almost all the way to the other end of the metal. When you're looking at the brake shoes with the drum off, the relieved area will be at the top of the front shoe and bottom of the rear shoe. If you have a decent manual, there will be a picture of this. If the shoes are on in the wrong position you MAY find the pedal is squishy no matter what you attempt to correct it. Not everyone reports this problem though.

Brake shoe adjustment is critical to getting a full, firm pedal. Proper drum adjustment is not "loose". With the parking brake off, you should be able to spin an elevated wheel by hand and and hear faintly a bit of scraping or drag. When you release the wheel after spinning it by hand, it should stop in about one revolution. If the wheel spins and spins, the brakes are too loose. When the rear brakes are out of adjustment you will get excessive pedal travel on the first pump of the pedal and on the second pump the pedal will be higher and firmer.

[miller 666]

What else have you done with the brakes? New or rebuilt calipers perhaps? Are their bleed nipples pointed "up"? Have you fit new shoes under the Mini Fins? If so, did you put the shoes on in the right position? (Yes, there is an order).

The metal backing of the shoes will have a relieved area NOT covered by friction material at one end... and the friction material will go almost all the way to the other end of the metal. When you're looking at the brake shoes with the drum off, the relieved area will be at the top of the front shoe and bottom of the rear shoe. If you have a decent manual, there will be a picture of this. If the shoes are on in the wrong position you MAY find the pedal is squishy no matter what you attempt to correct it. Not everyone reports this problem though.

Brake shoe adjustment is critical to getting a full, firm pedal. Proper drum adjustment is not "loose". With the parking brake off, you should be able to spin an elevated wheel by hand and and hear faintly a bit of scraping or drag. When you release the wheel after spinning it by hand, it should stop in about one revolution. If the wheel spins and spins, the brakes are too loose. When the rear brakes are out of adjustment you will get excessive pedal travel on the first pump of the pedal and on the second pump the pedal will be higher and firmer.

Yep i do get the faint scraping on both rear wheels and they do stop after about 1 revolution.

[dklawson]

It sounds like the brakes are adjusted right but as I asked earlier, are you confident that the shoes are on in the correct position?

Many people will encourage you to use EZ-Bleed or some other high-tech tools to bleed the brakes. I encourage you to use more primitive methods. I would start with nothing more than "gravity bleeding". Connect your bleed hose to the rear wheel cylinder furthest from the master cylinder, top up the reservoir and open the nipple. Wait and watch as the fluid slowly flows through the system. Don't let the reservoir fall too low, top it up periodically. Repeat this for the other side after maybe a half cup of fluid has passed through. You can then try this on the front as well.

After gravity bleeding the system you may need to do a more traditionally 2-man bleed of the system using the push and hold method (not the pump-pump-pump and release method).

I suggest these things as a possible way to slowly work the air through the system without disturbing the proportioning valve on the rear subframe. If it shuttles during bleeding you may get little or no fluid out of the rear lines.

[miller 666]

ok doug will give it a go. The brakes were working great before i took the subframe off and ive checked the shoes and they are in the correct way.

[bmcecosse]

I have never failed to 'gravity bleed' my brakes! Possibly the servo is knackered and just taking all the fluid ? Best to do away with it! Wee car like Mini doesn't need a servo - it's just a complication. Start bleeding at futhest point and work towrads the master cylinder.