ir3333
Well-Known Member
does that single reservoir have a residual pressure valve?
that could be another disc brake deal breaker...
that could be another disc brake deal breaker...
Brake Conversion
- Thread starter 64_Barracuda
- Start date
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So no the residual pressure valve is removed from the drum masters, however an I line valve is done before the prop valve, so I will give this some thought put 70 miles on her today, no issues, but the residual valve is on my mind.
But just as a rid bit, disks don't require the residual valve just the drums. It's in the service manual.
No they were all dealer installed. This its in both service manuals and the addendum's. Doesn't much matter what you have seen Tim, your very narrow minded person. Having seen the proof on an unmolested Formula car, just today again reinforces all my correct thought process on how and why Chrysler did what they did.
What is double or drum brakes mean anyway?
Please get out your service manual and study the Kelsey-Hayes section.
Hey I saw that car today.
65-66 Dealer installed Kelsey-Hayes by authorized dealers. It's in the manual
ir3333
Well-Known Member
..when you apply the brakes,the piston movement distorts the o ring and moves about .005.
..when the pressure is released the o-ring returns to shape pulling the piston back that same .005 for pad clearance.
if you use a residual valve on a disc system you will have constant contact and drag on the rotor.
newer drum brake wheel cylinders have springs to preload the cups so residual valves are no longer needed.
..when the pressure is released the o-ring returns to shape pulling the piston back that same .005 for pad clearance.
if you use a residual valve on a disc system you will have constant contact and drag on the rotor.
newer drum brake wheel cylinders have springs to preload the cups so residual valves are no longer needed.
Dealer installed equals factory to me as the option was engineered and endorsed by the factory. In mopars case the dealer installed items just did not contain a specific option code.
Don't think the formula s driver at show today that has driven this car from Va. to Carlisle multiple times was concerned about his original single master cylinder disc brake setup. LOL
Oldschoolcuda
Don't think the formula s driver at show today that has driven this car from Va. to Carlisle multiple times was concerned about his original single master cylinder disc brake setup. LOL
Oldschoolcuda
I am not narrow minded. "dealer installed option and factory" are two different things. I have seen several unmoested formula s cars, or supposed un mollested, all drum as from the factory, single resovour MC. The Dealer installed option disc brakes had a duel resovour MC. Im done here. Have fun, and dont be a DICK. Im not being one. Just trying to learn something here.
This discussion got me looking in my 65 Parts catalog and on page 5-8A the catalog lists Master Cylinder (Disc Brakes) - All Except Belvedere, Coronet and Imperial and shows a picture of the single master cylinder, then a gasket, then another part called a plate, then the additional reservoir. I can scan and post the page if anyone is interested in seeing it. The brake section does not list any disc brakes for the Imperial but does show 4 piston Budd calipers for the big Dodge, Plymouth and Chrysler. From the info I first listed, it appears the big C Bodies used the same extended master cylinder. One thing I noticed is that there's no part number listed for the additional reservoir. Would I use it? Absolutely not unless I were doing a complete nuts and bolts OEM restoration for judging like Ulf did.
Nothing wrong with difference of opinion Tim. Thats what a forums about. No one is being a dick and quite possibly Cali cars and others did have dual mc's as 65 and 66 were so changeable with all the new regulations upcoming.
Every single 65 formula s disc brake car I've seen personally has had a single master cylinder including the one in our local club.
Safe braking to all
Oldschoolcuda
Every single 65 formula s disc brake car I've seen personally has had a single master cylinder including the one in our local club.
Safe braking to all
Oldschoolcuda
Exactly, but let's,talk about how the wheel cylinders how do I know if my wheel cylinders are the newer type? Take off the boot maybe? Or if I bought new ones from napa would it already be residual type?
Thanks for posting this learned something new....
I will say this about residual valves when I called speedway I was looking at there brake circuitry diagram, they had residual valves on disks when I asked them about it they said this was for a hot rod with the master below the calipers (on the frame rail below the floorboard). I suppose that makes sense he said fluid could bleed back into the master.... Just a tid bit
ir3333
Well-Known Member
If you have no springs and no residual valve you will just have extra pedal travel until the additional clearance is taken up by the wheel cyl. pistons.You could take one apart but that's a pain.I think the more modern wheel cylinders with springs have been around a long time.
If your master is below your discs a residual valve can be used,but a small 2 lb unit.Something you would use on a deuce hi boy or hotrod were the master cylinder is below the floor on the frame
If your master is below your discs a residual valve can be used,but a small 2 lb unit.Something you would use on a deuce hi boy or hotrod were the master cylinder is below the floor on the frame
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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It also doesn't hurt to double up, eg.; to run both the cup expanders plus the residuals. The expanders are inside the wheel cylinders and cannot be seen, except by the complete disassembly of one side of the w/c. S'a lotta work for a look-see.
ir3333
Well-Known Member
yes.. boot/piston/cup/spring
good idea..a 10lb. residual back on the frame on the rear brake supply line
good idea..a 10lb. residual back on the frame on the rear brake supply line
And? Does the fact that it's "in the manual" make it not dangerous compared to a dual reservoir master cylinder?
Does the fact that it's "in the manual" make anything I said untrue?
Nothing about it being "in the manual" means that it's a safe alternative to a dual reservoir system. Nothing. No how. Nowhere. No time.
You're just arguing for the sake of argument, now.
The dual reservoir system is FAR SUPERIOR to ANY single reservoir system. PERIOD, END OF STORY.
That is fact. Plain and simple. When you kill someone you love because you are hard headed, you will realize it was you who was narrow minded.
Really? I think when the guy calls a member narrow minded for trying to HELP, that is being a dick. A big nasty one. Maybe you live in a different reality.
BillGrissom
Well-Known Member
I agree w/ 64_Barracuda on the single MC and anybody can use Google Images to verify the 1965 factory disk/drum design. Dual reservoir and disk brakes are separate issues and separate fed mandates (~1968 & 1974), though disk/drum cars benefit more from a dual MC. My 69 Dart had a dual MC drum/drum and the pedal went to the floor with no dash warning. I expect the "imbalance valve" in most cars is rusted in place so doesn't warn you when you loose half the braking. Even w/ a single MC there is a backup in the e-brake (plus engine braking), though rears-only greatly increases stopping distance.
My question is the photo of post #1. It appears the rotor and hub are separate pieces. True, or just a machining line? Also, if the 1976 BBP rotor had SBP holes added, why don't we see the BBP holes? I thought 1973+ rotors were an integral rotor/hub, or was that just in later after-market replacement parts?
Re prop valve, by selecting the correct rear wheel cylinder bores, you might get away without a prop valve. Factory prop valves (inside the "combination valve") were a fixed ratio, which may not be right as people change parts like tires, so perhaps many cars drive around non-optimal. Even with a single-pot MC, you can add an adjustable prop valve in the tube to the rears. It is really a separate issue.
Re residual valves, I understand today they are only for hot rodders who mount the MC below the floor. Wheel cylinder kits since ~1970's have cup springs that serve to keep air out as the pistons retract. I don't understand post #37 about the residual valve affecting pedal travel. Its purpose was to keep pressure on the system to keep air out by keeping the wheel cylinder piston rubbers tight against the bore. The shoes will retract until they contact the stud above the wheel cylinder, regardless. 10 psi residual pressure cannot beat the shoe springs. The self-adjusters are what affect pedal travel.
My question is the photo of post #1. It appears the rotor and hub are separate pieces. True, or just a machining line? Also, if the 1976 BBP rotor had SBP holes added, why don't we see the BBP holes? I thought 1973+ rotors were an integral rotor/hub, or was that just in later after-market replacement parts?
Re prop valve, by selecting the correct rear wheel cylinder bores, you might get away without a prop valve. Factory prop valves (inside the "combination valve") were a fixed ratio, which may not be right as people change parts like tires, so perhaps many cars drive around non-optimal. Even with a single-pot MC, you can add an adjustable prop valve in the tube to the rears. It is really a separate issue.
Re residual valves, I understand today they are only for hot rodders who mount the MC below the floor. Wheel cylinder kits since ~1970's have cup springs that serve to keep air out as the pistons retract. I don't understand post #37 about the residual valve affecting pedal travel. Its purpose was to keep pressure on the system to keep air out by keeping the wheel cylinder piston rubbers tight against the bore. The shoes will retract until they contact the stud above the wheel cylinder, regardless. 10 psi residual pressure cannot beat the shoe springs. The self-adjusters are what affect pedal travel.
Uh nope I just stated that I did a disk brake conversion, you all brought dual circuit up not me.
Bill
So your correct on what your looking at its a one piece rotor, except it was drilled and machined for 5x4. I am thinking of getting a second set and putting them up in the attic for safe keeping. When I ordered the kit I had the same concern you did but Wayne said he has them drilled and machined to whatever he needs in the kits he sells.
So the Kelsey-Hayes was a two piece rotor and hub, I am trying right now to get a rotor and hub separated, so far no luck.
But I think your right, I think I had a 78 LeBaron that might of had a two piece rotor hub deal.
Prop Valves, so I spoke to Chuck at inline tube and he said a lot of the valves depend on wether it's drum drum or disk drum and then.... How much the car weighs depends on the amount of distribution goes to the rear, I thought that was interesting. He couldn't tell me the amounts.
The way I understand it you should never get air in the system, what the residual valve does is keep the wheel cylinder full of fluid and not fill back into the master, residual valve can't do much more than that because of the springs in the shoes, that's why self adjusters need to be well adjusted, I thought mine were but after today they need tweaking.
Residual valves.... So I did find that in a single master on drum brake the valve is right in front and looks like a cup with holes in it, to keep the fluid up in the wheel cylinders, in the 65,66 disk brake cars there is a little valve next to the prop valve, saw it on my buddies car today, only thing is I don't know how many lbs that is.....
Thanks again Bill for not killing my post. I am just writing about my conversion, and how easy it was well minus the grinding a bit of calipers. I need to see if my slotted Mags don't hit and a buddy of mine as a rally rim I'll report back in a few weeks if they fit with no spacing....
pishta
I know I'm right....
The factory never installed them on the line in 65 (that started in 66) that is correct. They came in the trunk of the cars that were supposed to get the disk's as a late year option, dealer installed like the A/C and stripe IIRC, as well as other optionals that were introduced mid year. Although Chrysler engineered the 'upgrade' with factory K/H sourced pieces and part numbers, the single pot M/C was just retrofitted with an extension to provide the 8 disk pistons with enough fluid. It was an option, with Mopar part numbers and it was engineered with the donut reservoir for the single pot M/C. Now that is the first thing I say to replace as it is a dangerous (ie, no redundency) system. Easy enough to use a 67 disk/drum M/C as it bolts right in to same bolt pattern. The 66 FSM and a 65 addendum address the 'new' disk brake options for that model as they were available in 66 off the line with disc brakes.
source
source 2
source
source 2
BillGrissom
Well-Known Member
64, You can easily remove the residual valve by inserting a screw and tugging, as posts by 67Dart273 have shown.
For all the guys screaming "single pot is terribly unsafe", I ask why you haven't converted to the X-pattern dual system that most cars since the mid-90's use (fed mandate?). That system gives you one front brake when 1/2 of the system dies. Isn't it unsafe trying to stop w/ only 30% braking ability when your front circuit fails?
That said, I put a dual MC in my 3 old Mopars. I was re-doing brakes anyway, so why not go better, plus get rid of an ugly, heavy cast-iron MC. I didn't go to an X-pattern because that would require more plumbing (2 tubes to rear), plus engineer more parts to fit where none existed.
For all the guys screaming "single pot is terribly unsafe", I ask why you haven't converted to the X-pattern dual system that most cars since the mid-90's use (fed mandate?). That system gives you one front brake when 1/2 of the system dies. Isn't it unsafe trying to stop w/ only 30% braking ability when your front circuit fails?
That said, I put a dual MC in my 3 old Mopars. I was re-doing brakes anyway, so why not go better, plus get rid of an ugly, heavy cast-iron MC. I didn't go to an X-pattern because that would require more plumbing (2 tubes to rear), plus engineer more parts to fit where none existed.
Guys my best friend has a 65 formula s with disk brakes. The prop valve and residual valve are about a foot down the fender well. It's the second set I have seen.
The car is all stock if you have ever been to Carlisle you have seen it. It's won numerous awards.
I am pretty sorry I even said anything about my conversion. I am going to let this post sit a bit then delete it.
I've got pretty thick skin. Being active duty Navy for 25 years I just don't quite understand why so many folks here can't just respect someone's opinion and move on.
The car is all stock if you have ever been to Carlisle you have seen it. It's won numerous awards.
I am pretty sorry I even said anything about my conversion. I am going to let this post sit a bit then delete it.
I've got pretty thick skin. Being active duty Navy for 25 years I just don't quite understand why so many folks here can't just respect someone's opinion and move on.
So here is the picture from the 66 Manual and the 65 Service Manual Addendum. You can clearly see how the Barracuda, Valiant and Dart Disk Brake cars are set up.
The second picture is the Residual valve in the Master for drum brakes, this goes in front of the spring right before the outlet, you cannot remove this out the front it comes out the back.
The second picture is the Residual valve in the Master for drum brakes, this goes in front of the spring right before the outlet, you cannot remove this out the front it comes out the back.
Here is a picture of the Drum Master, the part in the front that says "valve" is the residual. This is the only difference between the disk.
Few more from the 66 manual. 65 same except the addendum I have is water logged.
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