Brakes locking up

[AndrewBird]

A bad booster could put pressure on the master cylinder, causing them to lock. Easy test is to unhook the vacuum line going to the booster the next time it locks up. If they release, then it is the booster.

[craiggroves91]

A bad booster could put pressure on the master cylinder, causing them to lock. Easy test is to unhook the vacuum line going to the booster the next time it locks up. If they release, then it is the booster.

They are constantly locked right now.
So thats a little tough. I might have time to mess with it tomorrow

[craiggroves91]

OKAY! so its pretty much most definitely something with the linkage, whether its the pedal adjustment, something installed wrong, something missing, etc.

I know this because I unbolted the MC nuts and slowly the brakes started freeing up and bam I can push the car with my pinky!!!

I'm going to try to adjust the pedal with the MC off to try to see when the rod is pushing and isn't pushing. If that makes sense. I'll let you know how that goes.

[craiggroves91]

Something is definitely not right and I have no idea what it is.
It seems like the booster needs washers on its studs to space it out.

the only time they are remotely freed up is when I screw the rod all the way into the pedal and even then they stick a little. The pedal is closer to the firewall then the gas pedal.

This makes no sense cause everything is factory and should be there.
Maybe something is missing where the rod pushed on the master? Everything seems to be there

It wouldn't do any harm throwing some washers on the booster to space it out more would it?

[jlevie]

Are you sure the pushrod clevis isn't binding on the pedal? With the booster displaced sideways you'd have to have an S-shaped push rod to avoid that.

[craiggroves91]

Are you sure the pushrod clevis isn't binding on the pedal? With the booster displaced sideways you'd have to have an S-shaped push rod to avoid that.

I have a modified clevis, so its displaced already.

I unbolted everything today and I was going to add washers to the booster and then I realized I should try to rule out the clevis so I grinded the side down that was touching the pedal slightly and it no longer touches.
They are still locking up, I haven't adjust the pedal much yet though.

[craiggroves91]

My pedal is adjusted to pretty much exactly Bentley's measurements. They are still rubbing and the master isn't even fully on.
I think I found the issue. When I first removed my booster I remember the rod came out of place, I think when I reinstalled it maybe rod wasn't seated in the right spot?



EDIT: Just got the rod out, its was just wiggling around in there
I have to figure out how to get it back in



Again another EDIT: I think this little rod is the problem. Its not seating correctly and I'm not 100% sure why.
I'm tempted to just grind it down and shorten it.

I managed to snap a picture of the inside of the booster and the spot where this seats is worn, I think thats causing it to not seat correctly and flat
You can see it looks like the rod was kinked down and me pressing the brakes caused it to wear.

[craiggroves91]

So out of desperation and frustration I ground the rod down a couple millimeters and BAM! Brakes are golden, no more locking up.
I don't see any harm in shortening the rod.

I'm not sure how permanent this will be, but I just need the car drive able so I can go get smog.

[jlevie]

That booster is damaged and needs to be replaced.

[craiggroves91]

That booster is damaged and needs to be replaced.

Eventually I'll replace it