New Brakes NO stop,

[Capt Mark]

Carl,

Yes, The nipples are on top......he he he.....too funny.....

I am going to do the booster anyways, that way I will have a complete new brake syatem........Will I have to take OFF the master in order to change the booster? or will I be able to move

out enough to get the bboster out?

[hls30.com]

I haven never tried to move it away and pull the booster-sounds like it is worrth a try, but keep an eye on your lines, better to have to bleed again than to replace a crimped or collapsed hard line.

Will

[kinfish]

Have you checked the adjustment of the rod between the brake booster and the master cylinder? If there is a big gap between the end of the rod and the piston in the master cylinder some of the brake pedal engagement will be used to take up the gap. Best method is to take detailed measurements to insure there is only a slight gap (.050) between the two after assembly. Be careful not to set the rod too long whereby the piston in the master cylinder has started to move after final assy. I experienced similar problem when installing new master cylinder and new brake booster. Later model boosters/master cylinders used adjusting rods of different length. I wound up using my original rod (as del'd from factory) with the new booster. After setting rod correctly, brakes work great.

[Bambikiller240]

I haven never tried to move it away and pull the booster-sounds like it is worrth a try, but keep an eye on your lines, better to have to bleed again than to replace a crimped or collapsed hard line.

Will

Exactly why I wouldn't even try it. (This is just the kind of thing that bites me on the a$$ everytime I try to save time/effort) Of course I have Speed Bleeders on the car so re- bleeding isn't any trouble at all.

[jmortensen]

99.99999% sure the reaction disk fell out. The reaction disk is a small rubber disk inside the booster. It sits right in the middle of the booster, and can fall out when you separate the master and the booster. It should be down in the bottom of the booster. Fish it out and put it back in its place. Everything should be good to go afterwards.

While I haven't had this problem myself I've seen quite a few posts about it over the years, and they all said exactly what you said: "Bled the system 57 times, everything is brand new, still no pedal."

[Bambikiller240]

99.99999% sure the reaction disk fell out. The reaction disk is a small rubber disk inside the booster. It sits right in the middle of the booster, and can fall out when you separate the master and the booster. It should be down in the bottom of the booster. Fish it out and put it back in its place. Everything should be good to go afterwards.

While I haven't had this problem myself I've seen quite a few posts about it over the years, and they all said exactly what you said: "Bled the system 57 times, everything is brand new, still no pedal."

Very good point.

A search should bring up several threads (some with diagrams, etc) on this subject.

[AChev]

I was wondering this when I was removing my mastter brake cylinder and lines. Is brake fluid a rust inhibitor or a cause of rust? I had thought it was an inhibitor but I found so much rust where brake fulid would have leaked.

[MikeW]

Is brake fluid a rust inhibitor or a cause of rust? I had thought it was an inhibitor but I found so much rust where brake fulid would have leaked.

The problem is that over time water can build up in the brake fluid and that can cause rust.

[Capt Mark]

Jon,

I checked it out and the reaction disk is in place correct, reconnected everything and still no vacuum assist from the booster, I went ahead and ordered a replacment today. $72

thanks for the tip, I will make sure it is in place when I put in the new one.

Mark

[Bambikiller240]

Did you check the "check valve" also? Maybe it's stuck?

[Capt Mark]

There was no check valve on the 70, I do plan on putting one on in the future.

[billcapp]

Are you absolutely sure you got the correct master? I believe the rod may be different from "newer" models. I do know the 71 vs. the 72 model years are different. I ordered one some time ago and was sold the wrong one. Didn't notice until lots of wasted hours trying to get it to work. Also be sure you get the same booster if you get another. Had a problem with that issue also...the attaching pin was different than what I had. Different thread size wouldn't fit properly.