The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1960 - 1966 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 12-03-2022, 12:18 AM   #51
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,495
Re: Brake vacuum

How much initial are you at now?
What’s your idle rpm?
geezer#99 is offline   Reply With Quote
Old 12-03-2022, 08:36 PM   #52
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

I checked my timing today but made the mistake of forgetting to plug the vacuum advance.

16 degrees of initial timing.

33 at 1500
Around 55 at 2500
Blueprint recommends 32-34 at 3500 (or at the point the mechanical timing stops advancing) for their engines. I didn’t feel comfortable taking it up to 3500 rpm

It was running at 600 rpm at idle which seems a little low so I bumped it up to 7.

The brakes are so close to working good. I think the semi metallic brake pads and boots with a vacuum canister will solve the problem.
forestb is offline   Reply With Quote
Old 12-03-2022, 09:44 PM   #53
theastronaut
Registered User
 
theastronaut's Avatar
 
Join Date: May 2011
Location: Anderson SC
Posts: 3,867
Re: Brake vacuum

Quote:
Originally Posted by forestb View Post
I have the cpp drop spindles also. Do you remember which brake pads you ordered for them?
I used the pads that came in their disk brake kit.
theastronaut is offline   Reply With Quote
Old 12-03-2022, 10:22 PM   #54
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by theastronaut View Post
I used the pads that came in their disk brake kit.
And those were semi metallic pads?
forestb is offline   Reply With Quote
Old 12-03-2022, 10:26 PM   #55
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

I also found out that I have a leak from my axle shaft seal that is probably causing that drum to fail.
forestb is offline   Reply With Quote
Old 12-03-2022, 10:28 PM   #56
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by forestb View Post
And those were semi metallic pads?
I have had my beak pads replaced sense the calipers were installed. Is there a way to tell if the pads are ceramic or semi metallic?
forestb is offline   Reply With Quote
Old 12-04-2022, 11:37 AM   #57
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,495
Re: Brake vacuum

Quote:
Originally Posted by forestb View Post
I checked my timing today but made the mistake of forgetting to plug the vacuum advance.

16 degrees of initial timing.

33 at 1500
Around 55 at 2500
Blueprint recommends 32-34 at 3500 (or at the point the mechanical timing stops advancing) for their engines. I didn’t feel comfortable taking it up to 3500 rpm

It was running at 600 rpm at idle which seems a little low so I bumped it up to 7.

The brakes are so close to working good. I think the semi metallic brake pads and boots with a vacuum canister will solve the problem.
So you basically have low initial timing combined with a higher idle setting both of which reduce your idle vacuum.

New pads and brake shoes won’t change how your brakes function.You still won’t have enough vacuum for your booster.
geezer#99 is offline   Reply With Quote
Old 12-04-2022, 12:41 PM   #58
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

If I set my timing according to wha blueprint recommends, what should I set my idle speed to
forestb is offline   Reply With Quote
Old 12-04-2022, 03:05 PM   #59
geezer#99
Registered User
 
geezer#99's Avatar
 
Join Date: Aug 2009
Location: Bowser
Posts: 13,495
Re: Brake vacuum

At whatever rpm your motor/trans are happy at.
geezer#99 is offline   Reply With Quote
Old 12-04-2022, 03:14 PM   #60
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,019
Re: Brake vacuum

^ Right. Do you have a stock converter?, or is it higher stall?
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 12-04-2022, 05:43 PM   #61
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by geezer#99 View Post
At whatever rpm your motor/trans are happy at.
I was under the impression from your last post that you thought the idle speed was too high so I was curious what you thought it should be.
forestb is offline   Reply With Quote
Old 12-04-2022, 05:48 PM   #62
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by Steeveedee View Post
^ Right. Do you have a stock converter?, or is it higher stall?
I know that when I had a turbo 350 transmission in it I had a non stock converter and that helped the brakes back then when I had a 308. I don’t know what the guy that installed the 700r4 put in it but he is the one who last looked at my brakes and he didn’t mention that as a solution.
forestb is offline   Reply With Quote
Old 12-05-2022, 02:50 PM   #63
88Stanger
Registered User
 
88Stanger's Avatar
 
Join Date: Mar 2015
Location: Washington State
Posts: 1,644
Re: Brake vacuum

Quote:
Originally Posted by forestb View Post
What brand of Hydro-boost did you get?
Damn sorry, I did not see this. I got the universal Breast kit from CPP for front and rear disc brakes. As mentioned, it is not cheap, but stopping is a good thing and being able to stop if it is a small person driving it is also a good thing, one of many reasons why I went with Hydro boost.
More info on my build of the "66 just recently..
__________________
John 3:16 - Saved me... God Bless
88Stanger is offline   Reply With Quote
Old 12-05-2022, 07:05 PM   #64
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

I talked to the guy that reset my timing and he used a vary imprecise way of doing it. He said he only set the initial timing at around 18-20 and listened for pinging and drove it around a little and was happy. I am either going to have to do it my self or take it somewhere that will fallow the blueprint directions.
forestb is offline   Reply With Quote
Old 12-30-2022, 11:40 PM   #65
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Spent a little time with Steeveedee checking the timing and adjusting the mixture. He figured out that the timing was set at what blueprint recommended and adjusted the mixture so that I have around 16 pounds of vacuum. My breaks are working a little better but have not completely fixed the backing out of the driveway problem. I will probably add a vacuum canister just to give it a little extra help. Thank you Steve for your time and it was fun getting to know you and meeting someone from the forum.
forestb is offline   Reply With Quote
Old 12-31-2022, 07:27 PM   #66
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,019
Re: Brake vacuum

Right on! Nice to have met you, too. If you have time on a non-rainy first or third Saturday, there is a meetup of all kinds of vehicles at the Firestone tire store in Thousand Oaks. I've only made it a few times since I found out about it, though. That's a nice truck that people can appreciate, there.
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 03-25-2023, 03:43 PM   #67
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

2 questions

1) on the stock single pot master cylinder are the bolts that connect it to the fire wall horizontal or at they more at around a 45° angle.

2) about 2 years ago I moved the bolt hole location for where the master cylinder push rod connects to the break pedal. I moved it around an inch lower because that is what I read you are supposed to do if you install power disk breaks. That was when I had my old engine and plenty of vacuum. Now that I have less vacuum because of my new engine I was wondering if it would be a good idea to move it back up to the top hole in order to get more leverage. I am trying to not have to push on my brakes as hard because I am trying to heal from a foot injury and don’t want to put too much pressure in that location. My plan is to also install a vacuum canisters.
forestb is offline   Reply With Quote
Old 03-25-2023, 06:06 PM   #68
AcampoDave
Registered User
 
AcampoDave's Avatar
 
Join Date: Feb 2013
Location: central California
Posts: 2,723
Re: Brake vacuum

I think diagonal. Here is left and right sides. You can see the old holes filled in with caulking. Inboard side low, outboard side high.
Attached Images
  

Last edited by AcampoDave; 03-25-2023 at 06:13 PM.
AcampoDave is offline   Reply With Quote
Old 03-25-2023, 06:48 PM   #69
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by AcampoDave View Post
I think diagonal. Here is left and right sides. You can see the old holes filled in with caulking. Inboard side low, outboard side high.
Thanks

Does anyone know of any companies out there make a dual port master cylinder that has that kind of bolt pattern if I want to go back to manual breaks that will work with my front discs and rear drums? I looked on the willwood, pol and cpp websites and either didn’t see anything or didn’t know what I was looking at.

Last edited by forestb; 03-25-2023 at 06:55 PM.
forestb is offline   Reply With Quote
Old 03-25-2023, 09:08 PM   #70
cwcarpenter98
Senior Member


 
cwcarpenter98's Avatar
 
Join Date: Jan 2018
Location: Hickory Flat, GA
Posts: 4,419
Re: Brake vacuum

On my 63, the original master was horizontal. The brake/clutch master and heavier duty trucks used the angled bolt holes. I don't believe the orientation of the master will change your braking performance.

Have you looked into potentially using a hydroboost system?
Attached Images
 
__________________
Christian Carpenter

1963 C10 - Frankentruck 283, 3 speed with overdrive
Overdrive wiring here
1963-ish truck bed trailer - Half-Wit

1981 C10 - Penny 305, th350

1995 Dodge Dakota Sport

"I'll put it simple: if you're going hard enough left, you'll find yourself turning right." - Doc Hudson
cwcarpenter98 is offline   Reply With Quote
Old 03-26-2023, 12:02 AM   #71
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by cwcarpenter98 View Post
On my 63, the original master was horizontal. The brake/clutch master and heavier duty trucks used the angled bolt holes. I don't believe the orientation of the master will change your braking performance.

Have you looked into potentially using a hydroboost system?
The reason I was asking about the orientation of the mc bolt holes was because I didn’t see any after market 2 pot master cylinders with the angled bolts and it looks like that’s what my truck has. I was more curious about where the rod connects to the break pedal and how that might help change things.

I have looked into the hydroboost system but a couple people on this thread were pretty negative about it and it’s kind of expensive.

At this point I am just looking for whatever will work best without my needing put too much pressure on my foot.
forestb is offline   Reply With Quote
Old 03-28-2023, 03:13 PM   #72
88Stanger
Registered User
 
88Stanger's Avatar
 
Join Date: Mar 2015
Location: Washington State
Posts: 1,644
Re: Brake vacuum

Quote:
Originally Posted by forestb View Post
The reason I was asking about the orientation of the mc bolt holes was because I didn’t see any after market 2 pot master cylinders with the angled bolts and it looks like that’s what my truck has. I was more curious about where the rod connects to the break pedal and how that might help change things.

I have looked into the hydroboost system but a couple people on this thread were pretty negative about it and it’s kind of expensive.

At this point I am just looking for whatever will work best without my needing put too much pressure on my foot.
I have installed 2 hydroboost systems on two different trucks and love the outcome. It is a bit expensive BUT for safety reasons I wanted great brakes and simple operations (referring to not much foot pressure needed to fully operate the brakes) so that if my older mother wanted to drive it, she could stop it.
With all this said, I have recently received a 1940 Chevy Coupe that is way far passed stock, all set up for racing. The brakes on it are a completely different system than I have ever installed. It is using Wilwood Dual Master Cylinders - one for front and one for rear. Then there is a brake pedal mount with a proportioning adjustment built in that allows me more pressure to front or rear and somewhat adjustable. This system was installed due to very low vacuum and no power steering (no fluid pump for the hydroboost). This dual master cylinder system is very cool, fairly simple but just like Hydroboost, it is not cheap.
Just wanted to throw out another option.
I went with Hydroboost for my current project and previous project and love the system.
Just my $.02 worth.
__________________
John 3:16 - Saved me... God Bless
88Stanger is offline   Reply With Quote
Old 03-28-2023, 03:31 PM   #73
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by 88Stanger View Post
I have installed 2 hydroboost systems on two different trucks and love the outcome. It is a bit expensive BUT for safety reasons I wanted great brakes and simple operations (referring to not much foot pressure needed to fully operate the brakes) so that if my older mother wanted to drive it, she could stop it.
With all this said, I have recently received a 1940 Chevy Coupe that is way far passed stock, all set up for racing. The brakes on it are a completely different system than I have ever installed. It is using Wilwood Dual Master Cylinders - one for front and one for rear. Then there is a brake pedal mount with a proportioning adjustment built in that allows me more pressure to front or rear and somewhat adjustable. This system was installed due to very low vacuum and no power steering (no fluid pump for the hydroboost). This dual master cylinder system is very cool, fairly simple but just like Hydroboost, it is not cheap.
Just wanted to throw out another option.
I went with Hydroboost for my current project and previous project and love the system.
Just my $.02 worth.
Thanks for all the input. Do you have a link to the Hydroboost system that you used?

I have seen the other system that you described on an episode of Roadkill Garage.
forestb is offline   Reply With Quote
Old 04-21-2023, 03:57 PM   #74
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Quote:
Originally Posted by 88Stanger View Post
I have installed 2 hydroboost systems on two different trucks and love the outcome. It is a bit expensive BUT for safety reasons I wanted great brakes and simple operations (referring to not much foot pressure needed to fully operate the brakes) so that if my older mother wanted to drive it, she could stop it.
With all this said, I have recently received a 1940 Chevy Coupe that is way far passed stock, all set up for racing. The brakes on it are a completely different system than I have ever installed. It is using Wilwood Dual Master Cylinders - one for front and one for rear. Then there is a brake pedal mount with a proportioning adjustment built in that allows me more pressure to front or rear and somewhat adjustable. This system was installed due to very low vacuum and no power steering (no fluid pump for the hydroboost). This dual master cylinder system is very cool, fairly simple but just like Hydroboost, it is not cheap.
Just wanted to throw out another option.
I went with Hydroboost for my current project and previous project and love the system.
Just my $.02 worth.
I ended up getting a Hydroboost. How did you connecting the the power steering pump return line (non pressurized) to the pump. My hard line that comes out of the pump is facing toward the front of the truck? Do you have any pictures.
forestb is offline   Reply With Quote
Old 04-21-2023, 03:59 PM   #75
forestb
Registered User
 
forestb's Avatar
 
Join Date: Jan 2009
Location: Burbank, CA
Posts: 3,581
Re: Brake vacuum

Sorry nevermind. I just realized that that line goes to the gear box so it should be facing forward.
forestb is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:10 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com