o/t: manual vs power brakes

[westcoastgalaxie]

Planning out disc brake conversion for my 62 galaxie and trying to figure out whether to go manual or power disks. I am planning on doing discs on all four corners. The current motor only makes around 11-12" in park and 8-9" in drive brakes applied. I doubt future motors will be any more vacuum friendly.

To me this means manual would be better to run, but I have my doubts about braking satisfaction. This is a cruiser that gets driven hard so power steering and power brakes are nice to have. If power is really the better way to go then I am willing to put in a vacuum pump. The simplicity of manuals is real plus.

Anyone here with real world experience that could offer up advice? Thanks

[TomP]

Manual would be OK if you could increase the pedal leverage for more pressue with less pedal effort and use soft pads. Otherwise go for power and just put up with all the "gimpy" jokes.

[plovett]

I have manual front disc brakes with drums on the rear.   I like 'em.  I don't know how much different manual 4 wheel discs would be.   Also, I have a lighter car.  It's a '67 Cougar.   So I'm not sure how applicable my experience is to your combination.

For sure stopping effort is higher, but I don't notice it in regular driving.  I don't notice it in hard stops either.  If I'm stopping hard it's because I'm scared and when you're scared you naturally push harder on the brakes,  LOL!   So for me it's a win-win.  The discs give me better braking power and removing the power booster and related parts is simpler and lighter.

JMO,

paulie

[cjshaker]

I never quite understood this "dilemma".
You don't need big vacuum at idle for brakes unless you live in a very hilly or mountainous area. I've always managed to run power brakes even with big cams. Think about this for a second....when you need brakes quickly, you will be decelerating. That's when you always have good vacuum, even with big cams, so you'll have the vacuum needed for stopping power. When you're stopped at a stop light, unless you're on a steep incline, you don't need big braking power, so even marginal vacuum will work.

My 427 has a 264@.050 solid cam, so vacuum is marginal. I DO have the small factory canister plumbed to help add vacuum, but it's so small (it's designed to only help with the vacuum operated modulators for heating/cooling controls) that its usefullness is questionable. When I decelerate from any speed I have plenty of stopping power. Enough that you would never be able to tell a difference from a mild/stock engine. Even when I'm stopping at mild speeds like 30-35mph. The only time I run out of vacuum is sitting still and I have to let off the brakes once or twice....then it uses up any vacuum left in the system and the brakes get tougher. But at that point it doesn't matter to me because I'm practically sitting still.

Of course it helps that I live in a pretty flat area. Like I mentioned above, if you live in a hilly area this wouldn't be the best set-up. And just as a side note, Trans Am racers used manual brakes. Manual brakes work GREAT as long as everything is working properly and the correct mastercylinder is used, but on heavier cars such as yours I'd want power.

[plovett]

Oh yeah, I use a Ford Maverick master cylinder designed for manual front disc brakes.  It works great.

paulie

[westcoastgalaxie]

Thanks for the info. As for vacuum necessity, I have power drums now and don't have enough vacuum run them safely. It's like stepping on a brick. I put in a reservoir and while it helps the stop and go traffic and mountain driving it is not enough.

Trust me I have checked the booster, vacuum lines, bleed the system, rebuilt all four, etc. and still the same.

[machoneman]

Thanks for the info. As for vacuum necessity, I have power drums now and don't have enough vacuum run them safely. It's like stepping on a brick. I put in a reservoir and while it helps the stop and go traffic and mountain driving it is not enough.

Trust me I have checked the booster, vacuum lines, bleed the system, rebuilt all four, etc. and still the same.

Funny, with the as-shipped OEM master cylinder, the car should stop w/o any excessive pedal pressure unless the check valve in your reservoir can is shot.

I also wonder if the prior owner(s) changed the original master to one with a bigger piston? Have no idea of exactly the original bore size of your vehicle's master but it may pay to check that and the current master's bore size. I mention this since even with a switch to discs, be it 2 or 4 wheel, you'd likely still have a rock hard pedal and poor stopping power.  Odd too is that the #1 & #2 causes of a hard pedal IS a bad booster or, as mentioned, low vacuum. 

http://www.mpbrakes.com/power-boosters-faq

You do have a dilemma since we here in the flatlands can usually get away with low vacuum and a vacuum canister like I do. But I can see how mountain driving would quickly use up stored vacuum. An electric vacuum pump or a Ford P/S hydroboost system as used on late model cars would give 100% duty to your vacuum needs...but are both pricey, for sure. 

[Heo]

Thanks for the info. As for vacuum necessity, I have power drums now and don't have enough vacuum run them safely. It's like stepping on a brick. I put in a reservoir and while it helps the stop and go traffic and mountain driving it is not enough.

Trust me I have checked the booster, vacuum lines, bleed the system, rebuilt all four, etc. and still the same.

I had the same problem on my 64 Galaxie untill i i bought high quality
brake shoes.  And not just some brand x shoes they had in stock
I dont remember the brand (maby Feroodo) but now i have realy good brakes
with realy nice pedal no fading not even from top speed to standing still
And later i found out i had a leaking booster 3 hours before the anual
tech inspection!! Forget about a repair kit for a 64 galaxie booster in Sweden
So i went through my booster collection and found a Volvo 142 booster
was easy to adapt. Master cyl bolted right on I had to make a 1/8" adapter
plate i bolted to the car and bolted the booster to the plate
When and if i go to a more radical cam i can use a Volvo 164 booster
with dual diafragm.
I have a set of spindles with discs but now i see no reason to do the swap
any moore

[fe66comet]

One thing to keep in mind is that the aftermarket brakes are much more powerful and efficient. You do not need as much effort to slow the vehicle due to you are increasing brake power by four or five times. At some point when increasing braking performance boosting power will actually reduce modulation and you will have issues with uncontrollable lockup. At this point a reduction in pressure is necessary, that is why brakes will have both front and rear proportion valves.

[cammerfe]

Go to Speed Mfg and look at the Hydroboost systems available. That sort of system came stock on my Lincoln LS DD and it's VERY good not only for daily, but for stopping from 150+.

KS

[Drew Pojedinec]

I have manual brakes in both my 76 F100 with a 390 and my 63 Galaxie with a 429, both are disc front, drum rear and stop just fine.

[cjshaker]

A common problem that usually isn't caught is a mismatch in pads vs. drum diameter. If the pads are much smaller than the drums, then you will have a very small contact area and poor braking. With turned drums and/or aftermarket parts, anything can be off, or of questionable quality or compatibility.

The master cylinder should be checked for piston size, as mentioned. And quality pads, as mentioned, ESPECIALLY in hilly areas.

[westcoastgalaxie]

Thanks for all the responses. I have had this car for 10+ years so I know the master is stock. The car braked fine, for drum brakes, until I did the last engine rebuild a few years ago. That is when my problems started.

I am switching to discs not to fix this problem but because of other reasons. I am in the planning stages of gathering parts to do this whole project so I was trying to decide power vs manual. At this point it seems like I might try manual first, if I am not happy then I can convert to power. Seems like I would only need to switch out the master cylinder and maybe the pedal/position, maybe the pushrod.

Still gotta tally up prices, parts list and all that so decision has not been made.