The Forward Look Network
The Forward Look Network
Search | Statistics | User Listing Forums | Chat | eBay | Calendars | Albums | Skins | Language
You are logged in as a guest. ( logon | register )

Adding power brakes - options?
Jump to page : 1
Now viewing page 1 [50 messages per page]
View previous thread :: View next thread
   Forward Look Technical Discussions -> Brakes, Wheels and TiresMessage format
 
oldhippie
Posted 2015-08-19 11:15 AM (#487530)
Subject: Adding power brakes - options?


Veteran

Posts: 131
10025
My 1960 Matador currently has manual brakes, and a single pot MC. I want to convert to a dual MC with power brakes and am looking for options. A buddy turned me on to these guys, and I wanted to know if anyone has any experience with them? Am I right in thinking this could be used with my current brake pedal assy, if they have something that will work with my model/year? It seems pretty pricey, once I add in the line kit, & such. How inexpensively could I add reliable power brakes to my car via other options?
Top of the page Bottom of the page
mstrug
Posted 2015-08-19 12:53 PM (#487536 - in reply to #487530)
Subject: Re: Adding power brakes - options?



Expert 5K+

Posts: 6487
50001000100100100100252525
Location: Newark, Texas (Fort Worth)
I am going to get a power brake booster for a cuda with a hemi. It raises the master cylinder up out of the way. On ebay for $224 with adjustable push rod.

http://www.ebay.com/itm/Mopar-8-Dual-Diaphram-POWER-Brake-Booster-M...
Top of the page Bottom of the page
57chizler
Posted 2015-08-19 1:03 PM (#487538 - in reply to #487530)
Subject: RE: Adding power brakes - options?



Expert

Posts: 3768
200010005001001002525
Location: NorCal

Any power assembly can be made to fit in the original MC location, easier if it closely matches the original MC bolt pattern....personally, I'd stick with a vacuum booster.

One problem you may have is the pedal ratio, the manual brake pedal ratio is a lot higher (6-1 to 8-1) than the usual PB ratio (4-1) so you could have "touchy" brakes with the higher ratio. A smaller booster with a large-bore MC like the popular 7" hot rod units might work better.

http://www.ebay.com/itm/7-ZINC-STREET-ROD-RAT-ROD-POWER-BRAKE-BOOST...
Top of the page Bottom of the page
oldhippie
Posted 2015-08-19 6:18 PM (#487559 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025
I hate to ask what may be a silly question, but can someone explain to me the calculation for the pedal ratio? I really don't understand what that's about...
Top of the page Bottom of the page
1960fury
Posted 2015-08-19 6:31 PM (#487560 - in reply to #487559)
Subject: Re: Adding power brakes - options?



Expert 5K+

Posts: 7385
50002000100100100252525
Location: northern germany
oldhippie - 2015-08-19 6:18 PM

I hate to ask what may be a silly question, but can someone explain to me the calculation for the pedal ratio? I really don't understand what that's about...


simply put, you got more leverage with the manual pedal. less effort but longer pedal (m/c piston) travel.
Top of the page Bottom of the page
oldhippie
Posted 2015-08-19 6:55 PM (#487562 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025
So, is it a difference in the pivot-point distance? (distance from the pedal anchor point to the m/c piston attachment point?) sorry again, but I've never seen these assemblies before and I'm finding it difficult locating these images online...

Edited by oldhippie 2015-08-19 6:57 PM
Top of the page Bottom of the page
60 dart
Posted 2015-08-20 12:12 AM (#487576 - in reply to #487530)
Subject: Re: Adding power brakes - options?



Expert 5K+

Posts: 8947
50002000100050010010010010025
Location: WHEELING,WV.>>>HOME OF WWVA
i've never really pondered the pedal lengths , never really had to but here's a question maybe someone can answer . if the pedal ratios are different between power and non-power
brakes , why do they have interchangeable bolt on pedal pad receivers -------------------------------------------later
Top of the page Bottom of the page
58coupe
Posted 2015-08-20 9:37 AM (#487608 - in reply to #487530)
Subject: Re: Adding power brakes - options?



Expert

Posts: 1739
100050010010025
Location: Alaska
57-61 Mopar manual and power pedal assys. are different but some manufacturers just have 2 holes in the brake pedal arm, one for power and one for manual.
Top of the page Bottom of the page
oldhippie
Posted 2015-08-20 10:46 AM (#487611 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025

That's what I was beginning to wonder - why not just change the mounting location for the piston linkage? I mean, as long as each end pivots, it seems like an effective method. Obviously it would require some calculations because it wouldn't be the same straight-line action, but...

Also, I found this picture, which helped me understand a bit better.
Pedal Ratio



Edited by oldhippie 2015-08-20 10:49 AM
Top of the page Bottom of the page
oldhippie
Posted 2015-08-20 10:51 AM (#487612 - in reply to #487530)
Subject: RE: Adding power brakes - options?


Veteran

Posts: 131
10025
Also found this interesting...

=====Pedal ratio/bore size vs. pressure output=====

'''Pedal Ratio''''''Bore Size''''''Pounds Input''''''Approx. PSI Out'''
6:11-1/875450
6:1175575
6:17/875750
 
5:11-1/875375
5:1175475
5:17/875625
 
4:11-1/875300
4:1175380
4:17/875500


Edited by oldhippie 2015-08-20 10:53 AM
Top of the page Bottom of the page
oldhippie
Posted 2015-08-20 11:01 AM (#487613 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025
Now that I see these numbers, I'm wondering... if I have a 6:1 manual pedal ratio, and change out the M/C to 1 1/8 bore size, wouldn't that reduce pressure enough to prevent the brakes from being "touchy"? On the other hand, were I to have a bore size of 7/8, is it possible that there would be enough pedal pressure that I wouldn't need a power assist unit at all? I would guess the only issue with a small diameter bore would be whether there was enough fluid to build pressure in all four caliper pistons!?
Top of the page Bottom of the page
ttotired
Posted 2015-08-20 5:43 PM (#487639 - in reply to #487530)
Subject: Re: Adding power brakes - options?



Expert 5K+

Posts: 8443
50002000100010010010010025
Location: Perth Australia
Yep

Smaller bore will require a longer piston travel to move the appropriate amount of fluid, which = a long pedal

This where the trade off happens, the small bore will give you really good brakes, but a really crappy pedal, so if you increase the m/c bore size, you decrease pedal travel, but increase the amount of force (from your foot) needed to operate the brakes

Top of the page Bottom of the page
oldhippie
Posted 2017-04-17 10:52 AM (#538238 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025
Been searching/reading the site for the last couple days on this topic - nobody mentions specifics, so I'm wondering if anyone could confirm if either of these might work, and if not, what might?

http://www.classicindustries.com/product/1972/mopar/parts/mn5008.ht...

http://www.classicindustries.com/product/1972/mopar/parts/mm3066.ht...

edit to add: now that I think about it, the rear axle I picked up has no brake components at all, so I'm buying everything new. Would it make sense for me to just get the rear disc conversion kit as well? If I wanted to do it in the future, I'd have to change out the master cylinder, right?

Just trying to weight the pros/cons of doing it each way. Thanks for any input!

Edited by oldhippie 2017-04-17 11:10 AM
Top of the page Bottom of the page
57chizler
Posted 2017-04-17 1:22 PM (#538248 - in reply to #538238)
Subject: Re: Adding power brakes - options?



Expert

Posts: 3768
200010005001001002525
Location: NorCal

The 2nd example is like the one Marc mentioned in the first reply, it uses the bracket that raises the booster and has a pivot that reduces the pedal ratio for use with the manual brake pedal/lever.

Your example uses the popular 4-wheel Corvette disc brake MC while Marc's uses the Mopar front disc MC.
Top of the page Bottom of the page
oldhippie
Posted 2017-04-21 6:33 PM (#538551 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025
thanks, think I'll probably be going with that 2nd example then.

Also, I found this interesting, but I wasn't sure where to post it - not sure it deserves its own thread, but some may find it useful...

https://www.youtube.com/watch?v=oi4BnNA3Ep4#t=2066.749825
Top of the page Bottom of the page
oldhippie
Posted 2017-04-22 9:16 AM (#538575 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025
Think I misunderstood earlier, but now I see the M/C differences. If I go with the MM3066 from Classic Ind, I'd have an equal-capacity M/C that would work if I eventually converted the rear to disc as well (prop. valve only needed), but if I want to use it for disc/drum setup, I'd need both a proportioning valve and a residual valve for the drums, correct? (neither of which come with that kit.)

The ebay one should have a residual valve in the M/C, right? Also, it comes with a prop valve. The only issue would be with the M/C, if I wanted to convert to rear disc later, I think?

(old one sold out, is this the same?) http://www.ebay.com/itm/Mopar-8-Dual-Diaphram-POWER-Brake-Booster-M...
Top of the page Bottom of the page
oldhippie
Posted 2017-05-25 6:04 PM (#540909 - in reply to #487530)
Subject: Re: Adding power brakes - options?


Veteran

Posts: 131
10025
Hrm. Now I'm just confusing myself. 1st link shows a setup for disc/drum (that looks surprisingly identical to the 2nd link below):

http://www.ebay.com/itm/Mopar-8-Dual-Diaphram-POWER-Brake-Booster-M...

2nd link shows a setup for disc/disc, but shows an unequal chamber M/C, which doesn't seem like it would have enough volume for the rear calipers (2 1/8" dia pistons):

http://www.ebay.com/itm/Mopar-8-Dual-Diaphram-POWER-Brake-Booster-M...

Both of these appear to have the 4-bolt M/C. This 3rd link shows a 1 1/8" bore, 2-bolt M/C that seems to be for teh same application, just from a different reseller.

http://www.ebay.com/itm/Mopar-8-Dual-Power-Brake-booster-1-1-8-bore...

When I talked to the reseller @ the 1st two links, they told me the M/C bore for theirs was 1", and that it would be enough volume for rear calipers!? Sorry if I'm being a P.I.A., but can anyone offer some advice? I've decided to go ahead and convert to 4-whl disc, which is why I'm re-visiting this topic.

Edited by oldhippie 2017-05-25 6:06 PM
Top of the page Bottom of the page
Jump to page : 1
Now viewing page 1 [50 messages per page]
Jump to forum :
Search this forum
Printer friendly version
E-mail a link to this thread

* * * This site contains affiliate links for which we may be compensated * * *


(Delete all cookies set by this site)