Is it a big job to change a PB booster on a 67 Parisienne?

cdnpont · Canadian Poncho Superstar!

Is it a big job to change a PB booster on a 67 Parisienne?

4SPEED427 · A Poncho Legend!

Bolting that part on is not bad other than a guy your size getting in under the dash to unhook the pedal rod. Those broad shoulders will make you unhappy when you try to fit in there!

If you already have the master off to change it, go for it. You know you won't be happy until you do!

cdnpont · Canadian Poncho Superstar!

I'm assuming they installed the booster before the dash in Oshawa?

I'll soon maybe fit Carl, down 45 as of today!

68sd396rag · Poncho Master!

Its a bit of a job but not bad-4 nuts on the inside of the firewall behind the brake pedal-then you have to hook up the lines and bleed the brakes. Have a pair of needle nose pliers to pull the clip on the brake booster clevice that attaches to the brake pedal-no big deal.Nuts will more than likely be 9/16".Undo the nuts first and then pull the clevice pin-otherwise you fight the nuts too much.A ratchet end wrench works great for this.By the way-that is not one of my boosters-its a Chinese knockoff-they look good-it will look way way better than a black painted one.

68 Grande · Guru

Just wondering why you are changing from 1 1/8 to 1 inch? I know you have changed your brakes to disc in the front but just curious what a 1 inch bore has for an advantage if any?

cdnpont · Canadian Poncho Superstar!

John, do you think the offshore booster will stand up, or is it junk? You wouldn't just happen to have a genuine one left over would you? biggrin

The 67's were zinc, at least on this build date,

I'm going to a 1" Earl to build higher brake pressure, through an increase in pedal travel with a corresponding lighter feel. The 1 1/8", while working well, has almost zero travel and has a big leg effort.

This should help, it's a common solution for a DYI system build.

Going with a Summit branded Wilwood knockoff, 760110.

4SPEED427 · A Poncho Legend!

cdnpont wrote:

I'm assuming they installed the booster before the dash in Oshawa?
I'll soon maybe fit Carl, down 45 as of today!

I'm more worried how you'll get those big shoulders past the seat so you can get your head under the dash. Losing weight won't make them any narrower!

68sd396rag · Poncho Master!

I don't have any experience with the offshore boosters,but a lot of guys are running them and I have not heard anything negative as of yet.That being said I have been away from this stuff for a while so take that for what it is.I may have one around-will check for you.Or I can restore the one that is on your car after you put the new import one on there in the mean time.

John

cdnpont · Canadian Poncho Superstar!

If you are still doing them, them I might take you up on your offer John. Thanks!

cdnpont · Canadian Poncho Superstar!

Carl Stevenson wrote:
cdnpont wrote:

I'm assuming they installed the booster before the dash in Oshawa?
I'll soon maybe fit Carl, down 45 as of today!

I'm more worried how you'll get those big shoulders past the seat so you can get your head under the dash. Losing weight won't make them any narrower!

The head will always be big, but at least I can bend over now without blacking out!

seventy2plus2 · Canadian Poncho Superstar!

If you want to give yourself a bit (well actually a lot) more room, remove the front seat. I think it's 8 bolts.

Canadian Poncho · A Poncho Legend!

Dumb question: If you change the bore, will you have to replace the rod from the pedal? Isn't there a bit of a science as to what length that should be?

68sd396rag · Poncho Master!

The rod length is determined by the depth of the hole in the master-its either shallow or deep. Rod on the front of the booster pulls in and out etc.. easily. If that's what you are asking? The length of the rod from the pedal shouldn't have anything to do with the bore diameter on the master. The only way you may need to replace the length of the rod from the pedal is maybe when switching from a Bendix to a Delco booster-there may be a different length there but I have not seen it yet. But I would never say never.

cdnpont · Canadian Poncho Superstar!

I think the in cab rod length stays the same Todd, and does not change in relation to the master bore. Although it is somewhat adjustable to make for incremental changes to the position of the foot pad, relative to the floor. For production tolerances? Experts educate please.

Here's a question; Can I use the top hole in the pedal arm with a power brake booster? Or will the pushrod angle end up excessive (dangerous)? If I could, would it not effectively raise the pedal ratio to that similar of a smaller bore master? Lighter pedal feel with the same overall braking effect ,at the expense of a longer travel. Has anyone tried this on a B Body PB system?

I just went out, stuck my phone up under the dash and got this. It's obvious the rod angle would ridiculously out. Does the manual master have a different rod, different angle, positioned in a different spot on the firewall? How does it mate up with the upper hole?

The master bolts. The pedal assembly bolts through the FW

-- Edited by cdnpont on Wednesday 4th of April 2018 04:54:54 PM

seventy2plus2 · Canadian Poncho Superstar!

I'm not sure where all the concerns come from.

Just unbolt your existing booster, and bolt on a new booster. There's only 4 studs out the back of the booster that go through the firewall, and 4 nuts in the passenger compartment holding them (you can see 2 of the nuts). Use the same hole on the brake pedal to for the clevis to go in to. The top hole on the brake pedal is for the brake light switch.

Canadian Poncho · A Poncho Legend!

This is what I was referring to:
techtalk.mpbrakes.com/how-to-series/got-a-soft-pedal-dont-forget-the-booster-pin-to-master-cylinder-gap

cdnpont · Canadian Poncho Superstar!

No concerns Clint, all is good, just some mundane talk around a booster is all.

I'll get in there and tackle it no issue when it finally warms up a little here. Cheers.

cdnpont · Canadian Poncho Superstar!

Canadian Poncho wrote:
This is what I was referring to:
techtalk.mpbrakes.com/how-to-series/got-a-soft-pedal-dont-forget-the-booster-pin-to-master-cylinder-gap

Oh yea Todd. When I added my big master and brakes on the 67 I spent some real time making absolutely SURE this clearance was correct! For a different reason. I made the mistake not checking it once on an old motorcycle I had, and the front wheel locked up in the rain 5 minutes from my house. The result was rather bad. The brakes had been dragging slightly, and once they heated up...bam.

Too tight is worse than too loose.

68 Grande · Guru

Mark, I have a question for you on the Summit master 760110.

Did you also change your rear drums over to disc as well, or does this Summit master accommodate a disc / drum applications?

The reason I ask is that I have a C3 kit in my basement (based on your very informed and detailed CP conversion posting) that will go the Grande this year but as I was digging through my parts, I discovered I ordered a disc / disc master cylinder, 1 inch bore instead of a disc / drum 1 inch bore. So, I was thinking, shoot, how did I do that?

So I was a bit confused with 760110 information in that it says disc or drum but not disc / drum application.

Thanks,

Jake

68 Grande · Guru

After reviewing your original post of Sept 24, 2013, I figured out why I ordered a disc / disc master for my conversion. confuse You have a paragraph discussing the application with a disc / disc master in that posting.

I guess the kit has been sitting in the basement a bit too long and forgot what I had ordered and why. I also ordered a proportional valve and a 10 lb residual as well so that explains my current parts.

Here is your original posting thread: http://canadianponcho.activeboard.com/t55068106/c3-corvette-front-brake-upgrade-on-my-67-a-summary/

Still a great template to follow for disc conversions on B Bodies!

Thx,

Jake

cdnpont · Canadian Poncho Superstar!

Glad it came in useful Earl. Hope the conversion goes well.