Guest 53Chief-239

Updating brakes

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Guest 53Chief-239

Hello members,

 

I have a 53 Pontiac chieftain that I am currently changing over from front drums to power disc brakes. I am also changing the location of the pedal from frame mount to firewall. My question is, do i need to get a brake booster with the new calipers or can I still use manual brakes?  any one have a generic kit model number they used with the brake pedal mounting kit?   I'm new to the classic car building. Would the booster work on a 239 straight 6 engine (converted to 12v)

 

Thanks.

Edited by 53Chief-239
adding engine type (see edit history)

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Just 2 cents worth here from someone who purchased their first "old" car in 1961 - it is a LOT more work to convert to disc brakes and change the pedal location than it is to have the original system properly rebuilt. It is also not as simple as people make it out to be to adjust the new front discs and the old rear drums to get the same stopping power you do with the original system. It is also a LOT more expensive and you gain nothing. If you go to resell and that is the only modification that you make you are going to eliminate a lot of potential buyers who want an original car - they will not even look at it - honest.  ........

 

Again, this is just two cents worth of advice from an old timer.

Edited by vermontboy
wording (see edit history)
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52 minutes ago, vermontboy said:

Just 2 cents worth here from someone who purchased their first "old" car in 1961 - it is a LOT more work to convert to disc brakes and change the pedal location than it is to have the original system properly rebuilt. It is also not as simple as people make it out to be to adjust the new front discs and the old rear drums to get the same stopping power you do with the original system. It is also a LOT more expensive and you gain nothing. If you go to resell and that is the only modification that you make you are going to eliminate a lot of potential buyers who want an original car - they will not even look at it - honest.  ........

 

Again, this is just two cents worth of advice from an old timer.

I agree completely. The reason most of us is here at this club site is because we like old cars and the way they look and drive. We want to experience what it was like and not re-engineer our cars. You also have to think about resale and also if you ever show your car it would be shown in a modified category. Try loving them for what they were not what you want them to be. Your 53 Brake system is so easy to completely restore including running new stainless steel lines you could practically do it with one eye closed. 

Edited by Pfeil (see edit history)
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When they say "bolt on" they really mean it will sort of fit on the car and you have to figure out how to make it work. What size master cylinder are you using with the disc brakes? That will make a big difference in how good the system works. Disc brakes also dont grab as good as drums so power assist is needed or you will have a hard pedal or a soft pedal that dont do much. Is the firewall reinforced enough to hold the master cylinder with a person pushing on it hard or will it bend and flex? Will your wheels fit over the brake calipers and rotors? Is the new master cylinder going to work with the new front calipers and the original rear drums? Will little GM discs stop as good as big GM drums?

 

We KNOW a factory setup will stop the car. Will a home made setup work at all? Bolt on kits arent bolt on and they usually leave the buyer to figure out the hard stuff. Read the various message boards and you will see alot of guys with the disc brake "conversions" having problems making them work right. Most guys blame the drums but its usualy bad maintanance that makes them not work right not a bad design. With a 6 in it your Pontiac wont have enuff speed to need discs anyway. I bet the drums if their set up right will stop the car better than discs anyway.

 

Good luck whatever you choose to do!!!

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One of the big problems is finding a shop that can change a tire, not to say set up the brakes properly on a 53 Pontiac.  I agree the original set up will be better with a lot less work.  I run synthetic (DOT5) brake fluid in my original 1928, external band brakes, it will lock up all 4 on pavement.  My 1929 827 will throw you right out of the seats, need to get seat belts in that car... (there is even a warning in the owners manual about "dislodging passengers") so it is most likely not your car.  The last Graham I did, only had one half, of one wheel cylinder still moving, it was stopping on 1/8th the braking power, brakes felt great, just no stopping power.

 

The better question might be how do we get the 53 to stop properly?  Are you comfortable doing your own work?  This job can be a big time eater.  If not, can we help find a competent shop in your area?

 

If you still want to do the disk brake conversion there are a lot of kits out there, they are all are a lot of work.  If you want it correct I still would find a shop that can help you (back to us).  My guess you will be into the kit and installation $2-3K range.  I would start with the GM guys, lots of kits for the 55 Chevs similar set up and similar car size.

Edited by Graham Man (see edit history)

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You might try the HAMB site as their forum members are more versed on the type of car you are building.  Good luck..consider a stock vehicle some time!  You are missing another great part of the hobby. 

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I say Go For It.  You've got the inclination, you've got a source for the basic parts, some time, some money. 

All you'll have to find are some:

15" disc brake wheels, plenty of those around.

a properly sized master cylinder, (there are websites that discuss how to size a master cylinder to your project.  Most of them are focused primarily on motorsports applications but that is what you are doing, isn't it?)

a proportioning valve

some brake pipes

a vacuum booster

some brackets to hang the booster

a brake pedal & linkage.  Probably would be best to go find a donor car and cut everything out of that car and put it all in your car.

And, oh, by the way, a good running engine to provide the vacuum to make the system function.  Once you fix the internal coolant leak in the engine problem the one you have should be fine. 

And when you are all done get it inspected through your state inspection process and and then go to your insurance company and tell them you want to buy insurance on a car that has a brake system you designed and installed all by yourself.  I'm sure they'll be excited to sign you right up. 

Then, god-forbid, if you ever hit anything, they never find out your car has a homemade brake system because if they do their lawyers will rip you apart to the point your descendants will still be paying long after you're carcass has been wrung dry.

 

 

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53 Chief, there is some good advice here but you came to the wrong forum for advice on a rat rod.  That is simply no what we do here.  That is why I suggested the HAMB site as it is perfect for your project.  There is a lot of expertise and some not so expert on our forums and all others.  Many here have decades of experience so they are relating THAT experience to you.  On any forum there are going to people who agree and who don't.  Separate what is of use to you and what is not.  In the meantime good luck with your project and I hope it comes out terrific and safe.

 

By the way, I drive a RACE CAR with 1941 drum brakes...they stopped the car in that day and sometimes actually slow my car down! :) 

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Why don't you ask the people who sold you the brakes? They should be the experts on their own products. If they don't know the answer, or won't tell you, that tells you a lot by itself.

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I took my drum brake car to a cruise night and some of the guys with disc brake conversions came over right away to check it out.

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I drive a 1953 Pontiac Chieftain 8 all the time and the stock brake system works just fine for me. I wouldn't change anything. 

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6 hours ago, Guest 53Chief-239 said:

I have a 53 Pontiac chieftain that I am currently changing over from front drums to power disc brakes.

I would have to think about the logic of this. Brake systems are normally designed for 55-45% split of braking effort front to back. If you put in disks, which one imagines to provide "more braking effort" in some unknown amount, are you expecting more braking effort at the front? Then you might have 65%-35% or 70%-30%? Should I expect a spin-out as the back kept going and pulled out to pass me, esp. if you are not dead straight ahead with the steering?

 

It seems to me that whatever system you design, you still need it to be balanced front to back at about the ratio that has been found to work. So then what is the advantage of adding disks to the front only? You should get earlier recovery after they are submerged... Maybe they won't fade as soon, although a lot of that is due to the fluid heating near the hot brakes and the water in the fluid vaporising.

Edited by Spinneyhill (see edit history)

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Lot of good points raised by the comments.  Having run both stock brakes and a front disc conversion, there is no question that there are numerous ways that a front disc conversion can go wrong and it is much more complicated than it seems:  wheel clearance on the disc calipers; need for a combination valve and residual pressure valves; master cylinder sizing; room for the vacuum booster, etc.  I have found that, despite all the trouble, a disc conversion, if done right, stops better.  However, most stock hydraulic brake systems (bounced my Model A with mechanical brakes off the curb numerous times to slow it down, but I am sure the clevis connections were worn out...) work just fine.  A good middle ground, that avoids the 'non-stock'/future sales issues is to simply replace the stock master cylinder, which is typically a single reservoir, with a dual master cylinder designed for a drum/drum combination.  Depending upon the subject vehicle, it may bolt right up to the cylinder mount or a simple adaptor plate can be machined to change a 3-bolt to a 2-bolt mount.  Make sure the cylinder size and plunger depth are correct and you can split the front and rear brake systems for an added safety factor--requires splitting the brake lines but (1) you would probably be replacing them anyway, and (2) easy to return to stock.  As the above comments point out, make sure the remainder of the system is in good shape--properly adjusted, good non-fluid soaked shoes, leak free--and the stock brake system should work fine on most vehicles. 

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If you go ahead with the conversion, document what car everything you use comes from.  At some point you or the next owner will need to replace something and you need to know what to ask for at the parts store.  Saying that its a '53 Pontiac will no longer work.  Also saying you need brake pads for a GM caliper won't work either.  Most parts guys can't even look up a part without year, make and model.

Edited by 61polara (see edit history)
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4 hours ago, Scott Bonesteel said:

( bounced my Model A with mechanical brakes off the curb numerous times to slow it down, but I am sure the clevis connections were worn out...)

 

I used a Model "A" as a daily driver back in the 60's and had no trouble locking up all 4 wheels. You adjust them on loose gravel (just like trailer brakes). IF you have ever felt a brake pedal go to the floor in a large car you will appreciate the positive action of mechanical brakes. I had that happen on a 1964 Chrysler Imperial - it is a helpless feeling.  I would never buy a Model "A" that had been converted to hydraulic brakes ...

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If you go through with the conversion, the discs will not help you one little bit unless you also install radial tires. It's not the brakes that stop your car, it's your tires. So, if you want a more economical way of improving your braking, put on radial tires. (I can't believe I even suggested that, cuz I can't stand the look of radial tires on cars that were not originally designed and delivered with them.)

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Or just lower the pressure in your tires so you have more rubber in contact with the road, same effect.

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19 hours ago, Steve Moskowitz said:

53 Chief, there is some good advice here but you came to the wrong forum for advice on a rat rod.  That is simply no what we do here.  That is why I suggested the HAMB site as it is perfect for your project.  There is a lot of expertise and some not so expert on our forums and all others.  Many here have decades of experience so they are relating THAT experience to you.  On any forum there are going to people who agree and who don't.  Separate what is of use to you and what is not.  In the meantime good luck with your project and I hope it comes out terrific and safe.

 

By the way, I drive a RACE CAR with 1941 drum brakes...they stopped the car in that day and sometimes actually slow my car down! :) 

I will just add, since I came from the HAMB. ( I Don't post there anymore since I try to keep my vehicles as stock as I can.) Anyway,  A lot of people resent rat rods. A lot of the guys like "traditional" rods. 

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You may have less brake fade with front disks when traveling down long  steep grades or repeated high speed braking.

Most conditions you will find not much improvement if any.

Years ago  aftermarket anti-lock systems were available.

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The comment about accidents and modified systems is spot on.  When I was hit by a car while riding a 3 month old new motorcycle, both lawyers in the case checked to see if my bike was properly inspected and set up properly.  Lucky for me I had proof the bike had received its 600mile dealer inspection as specified in the owners manual.  The bike had 1100 miles on it at the time of the accident.

 

Any time money and especially bodily damage is involved, everything has to be up to snuff.

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I have to say that upon purchasing my 56 Caddy twelve years ago, one of my first thoughts was to do a disk brake conversion.  I must say, however, I was discouraged by horror stories from two acquaintances who had done conversions and "never were really able to get them working right."  What finally convinced me to stay original, though, was the effectiveness of the stock system after I went through it all.  If you do the conversion, my $0.02 would be to find a shop who specializes in such conversions, and can give you references (and ideally, test drives) for their prior work.

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On ‎9‎/‎10‎/‎2018 at 1:55 PM, Steve Moskowitz said:

53 Chief, there is some good advice here but you came to the wrong forum for advice on a rat rod.  That is simply no what we do here.

 

I suggest that the OP is one and done. (chased off)

I didn't see any reference to a rat rod in his initial query.

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DON"T DO IT !!!!

I spent 15 years in dealership service departments as line mech and service manager.

You wouldn't believe the factory recall campaigns and what percentage applied to the braking system!

These were all systems designed by professional automotive engineers.

I think you are headed down the wrong road1

What is the goal? Bragging rights  or  stopping your car?.

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1 hour ago, JACK M said:

I suggest that the OP is one and done. (chased off)

I didn't see any reference to a rat rod in his initial query.

 

Jack,

You're late to the party.  His posting, now edited, mentioned he was rat-rodding this car and he had follow up questions regarding the original in-line 6 cylinder engine with an internal coolant leak, as in would it generate enough vacuum to make his booster function and he mentioned additional mods to the car, different steering, and some other stuff that I didn't really note, (didn't care).

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