Is it a big job to change a PB booster on a 67 Parisienne?
cdnpont said
Apr 3, 2018
I've had a rebuilt and replated booster on the shelf for years now, and since I'm about to replace the master, converting to a 1"bore from a 1 1/8", I'm thinking of using it as it looks so nice compared to the original one (which currently works perfect anyway, just ugly).
Is it a big job to replace the booster? Am I asking for trouble changing it to the new? I can't even remember where this came from. Could be offshore crap for all I know. I don't think it is one of 68s396rag's excellent boosters.
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 said
Apr 3, 2018
I'm assuming they installed the booster before the dash in Oshawa?
I'll soon maybe fit Carl, down 45 as of today!
68sd396rag said
Apr 3, 2018
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 said
Apr 3, 2018
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 said
Apr 3, 2018
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?
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.
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 said
Apr 3, 2018
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 said
Apr 3, 2018
If you are still doing them, them I might take you up on your offer John. Thanks!
cdnpont said
Apr 3, 2018
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 said
Apr 3, 2018
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 said
Apr 4, 2018
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 said
Apr 4, 2018
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 said
Apr 4, 2018
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
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.
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 said
Apr 5, 2018
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 said
Apr 5, 2018
After reviewing your original post of Sept 24, 2013, I figured out why I ordered a disc / disc master for my conversion. 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.
I've had a rebuilt and replated booster on the shelf for years now, and since I'm about to replace the master, converting to a 1"bore from a 1 1/8", I'm thinking of using it as it looks so nice compared to the original one (which currently works perfect anyway, just ugly).
Is it a big job to replace the booster? Am I asking for trouble changing it to the new? I can't even remember where this came from. Could be offshore crap for all I know. I don't think it is one of 68s396rag's excellent boosters.
Mark
If you already have the master off to change it, go for it. You know you won't be happy until you do!
I'm assuming they installed the booster before the dash in Oshawa?
I'll soon maybe fit Carl, down 45 as of today!
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?
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.
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!
John
If you are still doing them, them I might take you up on your offer John. Thanks!
The head will always be big, but at least I can bend over now without blacking out!
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?
-- Edited by cdnpont on Wednesday 4th of April 2018 04:54:54 PM
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.
techtalk.mpbrakes.com/how-to-series/got-a-soft-pedal-dont-forget-the-booster-pin-to-master-cylinder-gap
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.
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.
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
After reviewing your original post of Sept 24, 2013, I figured out why I ordered a disc / disc master for my conversion.
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
Glad it came in useful Earl. Hope the conversion goes well.