What did I do now?

[wildcard]

I had to change my brake light switch this evening. Now my brake pedal feels as if the brakes need bleeding. They have to be pumped up and when the pedal goes down, at the last second before it catches, there seems to be some type of catch. Any insight would sure nuff be preciated. I'm wondering if I done something when I pulled up on the pedal while changing out the switch.

[spartman]

I guess I would start looking for a leaking brake cyl and checking over your brake system.

If that all checks out it sounds like maybe the MC went bad on you and is now bypassing internally and the catch you are feeling is where the piston is hitting the end of the bore that isn't worn.

Kinda like a ring ridge if you know what that is.

Just my thoughts

[seattle67]

There is a keeper on the master cylinder that keeps the piston from coming out the back side, there is a slim chance that it came loose when you pulled on the brake pedal. That would allow the piston to come out too far, leaking fluid and letting in air.

It would easy to check this, just unbolt the brake push rod from the pedal, then unbolt the master cylinder from the firewall and pull it away from the firewall enough to inspect it. You wont need to unhook the brake lines, you will be able to move it far enough with them attached. Just be careful not to damage the brake lines when you do this.

The above advice is kind of assuming you have manual brakes.

[wildcard]

[ tried bleeding the brakes before reading the replies. Was in a hurry. spartman, the MC is only about 7 or 6 months old and has been working fine until this happened. The MC was full when I started, even after driving it 100 miles. No signs of leakage anywhere I could see at a quick inspection. Yes they are manual brakes seattle. I had meant to include that tidbit of info. Guess ya'll can't read minds. Sorry bout that. Anyway, when I tried bleeding them I never did see any signs of air in any of the three I got loose. The right front is going to come out and be replaced this weekend. So I suppose next woll be pulling the MC and checking the rod. Thanks guys.

[wildcard]

Guess I need to wear my glasses whrn typing at 3 30 in the AM.

[wildcard]

OK, I got a new MC and installed it today. Tried bleeding brakes again for about two hours. Was getting air out of lines but most of the time my son-in-law said the pedal either wasn't pumping up or it wasn't going to the floor when I cracked a bleeder valve. Still no brakes. Any ideas on what to try next? I use it as my daily driver for around 100 miles per day. So I kind of need to find a cure soon. I only have 2 traffic lights to go through so I don't use them much. But it sure would be nice to have them in a sudden stop.

[FORDification]

Did you bench-bleed the master cylinder prior to installing it? That's a must-do...you'll never get all the air out otherwise.

[wildcard]

No I didn't. Would that cause it not to even get any pedal at all? But they just all of a sudden started doing this with the old MC out of the blue. After changing the brake light switch, it was all of a sudden no brakes at all except parking. And they don't seem to try to pump up at all. But no sign of leaks anywhere.

[basketcase0302]

wildcard,

Would that cause it not to even get any pedal at all?

Yes it will.

There should have been two plastic fittings with two small rubber hoses that came with your rebuilt MC.
Use these to "bench-bleed" the MC, really pretty easy.
Install the twi fittings with the hoses, fill the MC with fluid and pump the pedal until you see no more air bubbles coming out.

Basketcase

[wildcard]

All that came with it were the instructions and rod. My son-in-law had the MC ready when I got the old one off, so I really didn't think to ask himabout bench bleeding.