Mushy Front Brakes

I'm just about to get my car on the road. I'm having some problems bleeding the front brakes. I disabled the rear brake master cylinder (unscrewed it rom the brake pedal and moved it out of the way), pumped up the pedal and released the bleed valves a number of times on each side until the fluid came out without any bubbles. I can still push the pedal to the floor. No matter what I do the pedal is way to soft. I back brakes work OK and the pedal has a nice hard feel (I disabled the front master cylinder first).

Has anyone had this problem? Tips???

Thanks in advance.

LG

The Master cylinder (MC) does not hold much fluid so while you may be pushing clear fluid through the bleed valve you may be putting air into the system upstream if the MC goes dry. If you have a helper to keep the fluid topped off as you bleed the system that may solve the problem. Have you have checked already for any leaks in the brake line connections?

Ralph

Your front brakes have two bleed screws per caliper, connect a t - fitting and two bleed lines to the bleed screws and one line from the t - fitting to the bleed container. Once this is done bleed the brakes using both bleed screws on each caliper at the same time. This will get the air out of the system. For some reason if you use each one individualy it wont get all the air out.

One other thing I've noticed that seems to be overlooked by some......

Is the caliper bleed screws positioned so that they are at the "top" of the cylinder?

I've heard that it's possible to mount the right caliper on the left side and vice versa.... placing the bleed screw at the bottom of the cylinder. Not saying if this is your problem, but you might take a closer look at where the bleed screw is located in relation to the "12 o'clock" position on the cylinder.

And I'll assume that when you're bleeding the brakes, you're tightening up the bleed screw before your helper lets the brake pedal return to the top.

Thanks for the tips. I did run into the problem of the MC going dry but kept a close eye on that after the first time. And I did have a friend help by making sure the bleeder valve was closed when the pedal went to the floor. We did all of this quite a number of times but the pedal was still to soft.

I'll try bleeding both valves on each side at the same time.

Regards,

LG

I don't disconnect the front or rears, I bleed one front and one rear at the same time. I use a little jar and hose arrangement you can get at any autoparts store. I put the jar in such a way that the bleeder screw is always covered with fluid. Don't open the screw much at all, only enough to let fluid out... if you open it much more, it will suck air in around the threads on the release stroke (much easier to suck in air then it is a column of brake fluid). About half a turn if memory serves, open it the minimum amount. Common mistake when bleeding brakes. I here that removing the bleeders and coating the threads with grease helps but I have never had to resort to doing that. With the bleeders open and the jars in place, I pump the peddle slowly, by hand, about three times and top off the master cylinder. This is the way I have always done it and the pedal feels like a brick wall. One man operation with little fuss.

Could be that the bias is letting the peddle go to the floor board even though the front brakes are bled.
when you bleed all the air out the MC gets harder and pushes the bias back with the rear MC is disconnected. Did you have a hard pedal when you reconnected the rear MC. I had this problem and it was fine when I reconnected everthing.

Also make sure the bias is adjusted correctly. The threaded rod needs to favor the left by twice as much as the right.

i'm confused. aren't there 4 bleeders on each front caliper, not 2? (see photos) even if you use a tee fitting what is the best order in which to bleed them?.
it seems from this post and the archives that bleeding this system is tricky. has anyone tried one of those pump-up tanks that screws onto the master cylinder reservoir?

LG -

Read this previous topic.... may help -

http://www.uniquecobra.com/showthrea...leeding+brakes read GeorgiaSnake's reply

The caliper has 4 bleeders because it can be used for right or left hand application. Only the upper screws are bleed screws not the bottom ones.
Remember air will rise, go to the top.

ah-ha. thanks. jo