Please help me on brake conversion!

[Gnfanatic]

I still have my original 9" dual diaphragm booster on my Monte which also gives me the clearance for the BBC and it works perfect with a vacuum canister and a pulley driven vacuum pump that pulls a constant 28 lbs.
View attachment 203692

beautiful work. I prefer not having a vac pump , maybe a canister if needed.

 

[565bbchevy]

beautiful work. I prefer not having a vac pump , maybe a canister if needed.

Thanks for the compliment, with a 750 lift cam I need some sort of vacuum assist for brakes, on my Regal I just have a canister for extra reserve.

 

[CopperNick]

565BBChevvy makes a good point about having that vacuum canister. Your low pedal could just possibly be a case of insufficient vacuum. Have you taken any opportunity to put a vacuum gauge on the port that feeds your booster and noted how much vacuum the engine is generating at idle? it would also be useful to rig a long delivery hose and tap into that vacuum line to set up a remote gauge in the cabin on a temporary basis to see what you get when driving .

As for the cost of the proportioning valve spool stop, it's cost depends on from whom you source it. Getting it from someone like Summit or similar might be cheaper than dealing for it with a Speed Shop. You mentioned ordering it which I take to mean that you may have gone on line and scored it off the internet. Location, location, location.



Nick

 

[Gnfanatic]

565BBChevvy makes a good point about having that vacuum canister. Your low pedal could just possibly be a case of insufficient vacuum. Have you taken any opportunity to put a vacuum gauge on the port that feeds your booster and noted how much vacuum the engine is generating at idle? it would also be useful to rig a long delivery hose and tap into that vacuum line to set up a remote gauge in the cabin on a temporary basis to see what you get when driving .

As for the cost of the proportioning valve spool stop, it's cost depends on from whom you source it. Getting it from someone like Summit or similar might be cheaper than dealing for it with a Speed Shop. You mentioned ordering it which I take to mean that you may have gone on line and scored it off the internet. Location, location, location.



Nick

Nick, I get 17 psi of vac at the port.

 

[Gnfanatic]

For the hell of it my friend at the part store gave me a gbody booster to try. Did not fix anything, same issue.

 

[64nailhead]

GN/GNX guys, is the brake pedal rod for the hydroboost setup in the same location as the vacuum brakes?

 

[Gnfanatic]

GN/GNX guys, is the brake pedal rod for the hydroboost setup in the same location as the vacuum brakes?

No it is not, vac brakes have a diff pedal which must be used for conversion.

 

[64nailhead]

No it is not, vac brakes have a diff pedal which must be used for conversion.

I'm asking because manual brakes have an attaching point for the rod closer to the pedal pivot. The result is shorter throw on the MC and a longer lever for easier brake pedal pushing. If your pin is in the upper hole on the pedal, then it will result in exactly what you're experiencing. That was the reason for my question. I have an '86 Regal 8' from me that I could look at haha.

 

[Gnfanatic]

I'm asking because manual brakes have an attaching point for the rod closer to the pedal pivot. The result is shorter throw on the MC and a longer lever for easier brake pedal pushing. If your pin is in the upper hole on the pedal, then it will result in exactly what you're experiencing. That was the reason for my question. I have an '86 Regal 8' from me that I could look at haha.

Hey. I just checked. My pivot is on the bottom and there is a hole right above it. SO I am almost positive I have the right brake pedal. Ignore the rod, I know it is not full seated 🙂

 

[64nailhead]

Hey. I just checked. My pivot is on the bottom and there is a hole right above it. SO I am almost positive I have the right brake pedal. Ignore the rod, I know it is not full seated 🙂

I can't tell in that pic. But if you have two holes, then you need the lower one (I'm 90% on that). I converted to manual brakes and had to move it to the upper hole in the pedal. And I've redrilled a couple for manual brake conversions on ...... Fords (don't tell anyone about the F word.)