Master cylinder upgrade

[Marlar]

A.I.M. = Assembly Instruction Manual - all the vendors have them. You'll also use the previously-unused lower hole in the pedal for the pushrod to the booster, and they should have included a bracket that bolts to the now-unused upper hole in the pedal that will operate the brake light switch.

Thanks. Vendor tells me the bracket referenced by birdball is for the bottom bolts and is not needed for this application. I also am told that a pair of existing studs need to be removed and replaced by supplied bolts. Just whack them out with a hammer? Hmmm, hammer and fiberglas firewall don't seem to be a good mix.

:confused

 

[birdball]

I think the vendor got you a little mixed up. You have to remove the lower studs that are spot welded to the brake pedal bracket under the firewall. That's sort of a pain, but you can do it with a die grinder and hammer. There is also an upper bracket that rivots to the firewall inside of the vent grill area that has the nuts for the upper bolts to screw into. I made my own for free, but most vendors have the bracket for about $25... I think they are confusing that add on bracket with the lower pedal bracket or something?!

Matt

 

[JohnZ]

Here are the upper legs on the booster that bolt through the top of the firewall into the anchor plate that's installed on the back side, below the vent grille. If Eckler's told you you don't need those attachments, that's why they should stick to T-shirts, jackets, and jewelry. :eyerole

 

[Marlar]

Birdball and John Z:

I am slowly getting there. After positioning the vac booster + master cylinder, I drilled the two upper bracket holes into the grilled area containing the windshield wipr mechanism. I then made an inner and outer 12 gauge straps to reinforce the install of the piece thru the fiberglass firewall. It does not seem necessary the cut the old upper studs since the are short and do not interfer with the MC/Booster piece. I will just cover them with push on chromed acorn nuts.

Since I have not started to hook up the pedal, I am still unclear about the info you guys provided regarding unused holes in the brake pedal assembly and a piece to make the stop lights work. The only extra piece in the box with the MC/Vac beyond a piece which threads onto the backside of the Vac booster with a pin/cotter key appears to be a rod with an O-ring. I have no idea what that is to be used for.

Installing the hydraulic lines was a b#&*!, but it got done. Custom prebent lines now seem a bad idea when you run a bunch of bends thru constricted areas in the frame!

I note that after pulling the left rear wheel that the caliper has two bleed valves, one inside and one outside. I assume both need to be bled?

:confused :confused

 

[birdball]

Hey Marlar- I double checked my booster this weekend while working on the car- I left the studs from my old single master on the firewall too, and you use the lower 2 holes for the lower legs. I made my own strap for the upper legs like you did. I also did not use an extra bracket for the brake light switch, as my brake switch is activated off of the brake pedal lever like before (could be mine was set up wrong to begin with!). You may notice that there are two holes on the brake pedal lever, and the non-power brake push rod was in the upper hole- I had to move the power booster rod into the lower hole which reduces the lever ratio, but also gives you better pedal feel.... The lower ratio doesn't really effect you now that you have power brakes...

You will need to bleed both sides of the caliper to make sure there is not any trapped air in there.

 

[Marlar]

Hey Marlar- I double checked my booster this weekend while working on the car- I left the studs from my old single master on the firewall too, and you use the lower 2 holes for the lower legs. I made my own strap for the upper legs like you did. I also did not use an extra bracket for the brake light switch, as my brake switch is activated off of the brake pedal lever like before (could be mine was set up wrong to begin with!). You may notice that there are two holes on the brake pedal lever, and the non-power brake push rod was in the upper hole- I had to move the power booster rod into the lower hole which reduces the lever ratio, but also gives you better pedal feel.... The lower ratio doesn't really effect you now that you have power brakes...

You will need to bleed both sides of the caliper to make sure there is not any trapped air in there.

Thank you. sir birdball:

I feel a tad better now. I have sent a question to the vendor regarding the extra shaft apparently for the vac booster to master cylinder that was included in the box. I think it is used for non '67 master cylinders attached to the vac booster. The unit I ordered is a master cylinder for a '67 and was bolted to the vac booster. I am assuming it has the correct (longer) rod installed. I suppose I can take them apart to make sure something is in there. lol.

otfl

 

[Marlar]

Hey Marlar- I double checked my booster this weekend while working on the car- I left the studs from my old single master on the firewall too, and you use the lower 2 holes for the lower legs. I made my own strap for the upper legs like you did. I also did not use an extra bracket for the brake light switch, as my brake switch is activated off of the brake pedal lever like before (could be mine was set up wrong to begin with!). You may notice that there are two holes on the brake pedal lever, and the non-power brake push rod was in the upper hole- I had to move the power booster rod into the lower hole which reduces the lever ratio, but also gives you better pedal feel.... The lower ratio doesn't really effect you now that you have power brakes...

You will need to bleed both sides of the caliper to make sure there is not any trapped air in there.

Things have proceeded fairly normally, ie, surprises here and there. The latest one is the bleeder valve in the left front caliper is broken off way down in the caliper! I should get that repaired maybe this weekend. While the car is up on jack stands, I ordered some rear shocks which are now back ordered. I did finally get the pressure bleeder garget sealed up and working, so as soon as I get the bleeder valve issue fixed, it should be smooth(er) sailing. All the help is greatly appreciated and not once has anyone gotten snipy, just helpful. As a nonexpert Vette wrench turner, that is nice.

:BOW

 

[Marlar]

Upgrade is done!!

All who have helped:

The upgrade of my '65 brake syatem to the '67 MC with vacuum assist (and all chromed) is complete and working well. All of the assistance you folks have provided is greatly appreciated.

Thanks