Dual chamber master cylinder for drum brakes

[Lamar Wadsworth]

Need to replace the master cylinder on my '55 Ford. Keeping stock drum brakes. Is there any particular late '60s-early '70s dual chamber MC for drum brakes that someone can recommend that you have used in this application? I think dual chamber MCs became standard on everything around '66 or '67. I remember a '69 Dodge A-100 van and a '72 Ford pickup I had both had dual chamber MC, drum brakes all around, and no power booster. Wondering if one of those might work, or something for a mid-size Ford car of that vintage? I can do the brake line plumbing to separate front and rear brakes. I know Rambler was the first to have that feature in the early '60s.

[fordor41]

I would think a 70's Mustang would work. just make sure bore is same diameter. If you have a non-power M/C now, stick with non-power M/C as the pocket in the cylinders are different between power and non-power.I don't know why a dual M/C for disc in the front wouldn't work if that's all you can find. may want to add a 10# residual in the front(disc take 2#)as some dual drum/disc M/c's have internal residual valves (2# &10#) and would have wrong RPV for front drums

[JeffB2]

Originally Posted by Lamar Wadsworth

Need to replace the master cylinder on my '55 Ford. Keeping stock drum brakes. Is there any particular late '60s-early '70s dual chamber MC for drum brakes that someone can recommend that you have used in this application? I think dual chamber MCs became standard on everything around '66 or '67. I remember a '69 Dodge A-100 van and a '72 Ford pickup I had both had dual chamber MC, drum brakes all around, and no power booster. Wondering if one of those might work, or something for a mid-size Ford car of that vintage? I can do the brake line plumbing to separate front and rear brakes. I know Rambler was the first to have that feature in the early '60s.

The one we have used over the years in the HAMB 1952-59 Ford Group is the Autozone M1485 this is a rebuild unit,so why a rebuilt you ask ? A lot of these are USA made Bendix or Raybestos castings which are better than the offshore new ones made in India or China if they have a few in stock look for the Bendix on the underside. This is listed for 1967-68 Mustangs with drum brakes. Here is a NOS one so you can compare. https://www.ebay.com/itm/NOS-67-70-F...-/402045990606 WARNING ! Do Not use the pushrod that comes with some of these, you should use your stock 1952-56 push rod. The push rod that comes with some of these has a clip that will lock it in place,removing one is pure Hell you can also toss that clip off the end too.

[KULTULZ]

...may want to add a 10# residual in the front(disc take 2#)as some dual drum/disc M/c's have internal residual valves (2# &10#) and would have wrong RPV for front drums

A #2 RPV (Residual Pressure Valve) is used only on a DISC BRAKE CIRCUIT if the MC is located under the front caliper, say a 56 F100. It prevents fluid drain-back from the caliper to the MC at rest leading to a spongy pedal.

If you buy a late replacement MC, it will not likely have #10 RPV(s) installed. You then must plumb in inline RPV's to both circuits..

I don't know why a dual M/C for disc in the front wouldn't work if that's all you can find

Differing bore sizes and fluid pressure/volume.

[KULTULZ]

Originally Posted by JeffB2

Do Not use the pushrod that comes with some of these, you should use your stock 1952-56 push rod. The push rod that comes with some of these has a clip that will lock it in place,removing one is pure Hell you can also toss that clip off the end too.

AMEN!

BTW - That clip is available and has an important function.

If I were to do a conversion today, I would find a correct take-off and have it sleeved/rebuilt. The RPV's used to come in the FORD rebuild kits.

[Lamar Wadsworth]

Sponsored Links (Register now to hide all advertisements)

Good info, thanks!

[frnkeore]

Regarding the PB MC, the main difference, is in the diameter of the piston. On most Ford's, up until at least '70, the non PB unit, had a 1" piston, the PB, had 7/8".

The smaller piston, will give you higher pressure, to the wheel cylinders but, with a little more brake pedal travel.

[40 Deluxe]

Originally Posted by Lamar Wadsworth

Need to replace the master cylinder on my '55 Ford. Keeping stock drum brakes. Is there any particular late '60s-early '70s dual chamber MC for drum brakes that someone can recommend that you have used in this application? I think dual chamber MCs became standard on everything around '66 or '67. I remember a '69 Dodge A-100 van and a '72 Ford pickup I had both had dual chamber MC, drum brakes all around, and no power booster. Wondering if one of those might work, or something for a mid-size Ford car of that vintage? I can do the brake line plumbing to separate front and rear brakes. I know Rambler was the first to have that feature in the early '60s.

Make sure you will have sufficient pedal travel to completely bottom out the piston(s) in the master cylinder. Check before adding the brake fluid.

When you lose fluid/pressure on one side of a dual master cylinder the pedal will go almost completely to the floor before any braking action occurs. If the linkage is not engineered right, the pedal may hit the floor before the piston in the master cylinder travels far enough to apply the brakes.
When all is buttoned up and bled, crack a bleeder screw loose on a rear wheel cylinder and see if you can stop (don't do this in the garage in front of your work bench!). Close the rear bleeder and repeat on the fronts. Rebleed if necessary.

[34pickup]

1967 Fairlanes also had dual master cylinder drum brakes. Except the GT that had disc fronts.

[JimNNN]

It sounds like you're getting some solid leads, Lamar. I put a dual reservoir on my '54 wagon with drum brakes maybe 8-10 years ago. I don't remember where I got it, or if the '54 application will work for '55, but if you strike out on your leads, pm me and I'll try and track down the receipt, which I'm pretty sure I still have. I won't bother looking until you need the info, though.


I know I bought it as something that was marketed as an upgrade to 2 reservoir for '54 Fords, so it wasn't some crap shoot engineering effort. It's worked good over the years.

[KULTULZ]

The period DUAL RESERVOIR MC(s) you want are 1967-1973 FORD INTERMEDIATE (FAIRLANE-MUSTANG).

DRUM/DRUM and DISC/DRUM are included for availability I had the chart (from the 1965/1972 MPC), that shows application, manual/power and bore size. The text would also include info regarding the valving used in the period.

I have a current computer problem(s) and will post that info as soon as I can.

If you buy a current production replacement MC, it will most likely not have the RPV(s) in the outlet circuits. You will have to plumb inline valves.

[JimNNN]

Lamar, I got your message, but don't think my messages are getting back to you. I can't find my receipt, but will take a pic of what I've got and send it to you. I'd bet KULTULZ's recommendation is the way to go. He's kinda the man around here. Nevertheless, I'll get a pic of what I've got to you, if I can.

[KULTULZ]

Just a warning, beware of these so-called disc brake changeover vendors. Few seem to have full comprehension and now are supplying off-shore parts.

Case in point, this individual went to an EvilBay vendor with a four wheel manual drum pickup and talked to the guy. Said he wanted power dual reservoir drum for now but would like to add front disc later.

Below are photos of what he was sold and installed-

Now he has to can it and start over.

[Flattop]

What style residual pressure valves (rpv’s) are you using?

[V8 Bob]

Originally Posted by KULTULZ

Just a warning, beware of these so-called disc brake changeover vendors. Few seem to have full comprehension and now are supplying off-shore parts.

Case in point, this individual went to an EvilBay vendor with a four wheel manual drum pickup and talked to the guy. Said he wanted power dual reservoir drum for now but would like to add front disc later.

Below are photos of what he was sold and installed-

Now he has to can it and start over.

All he has to do is switch the lines going into the combo valve, so the secondary (smaller) rear brake M/C chamber goes between the prop valve adjuster and pressure switch, and the larger front M/C chamber goes to the front of the pressure switch with the two output ports. When front discs are installed, removal of the red 10 lb residual is all that's needed.

[KULTULZ]

Originally Posted by V8 Bob

All he has to do is switch the lines going into the combo valve, so the secondary (smaller) rear brake M/C chamber goes between the prop valve adjuster and pressure switch, and the larger front M/C chamber goes to the front of the pressure switch with the two output ports. When front discs are installed, removal of the red 10 lb residual is all that's needed.

Why would one install an ADJUSTABLE BRAKING BIAS VALVE on a four wheel drum application? All he wanted was a split reservoir w/ booster. Did the vendor a$$-u-me the secondary circuit has an internal RPV? What about MC bore size?

All replacement MC's for that period do not include RPV(s) as later applications (1974- ) did not use an RPV and the deletion reduces inventory.

You see value in what he was sold? You would modify yours or a customers car in such a manner?

[V8 Bob]

KULTULZ,
You're right. I somehow confused this thread with one where front discs were going to sometime replace the drums. My bad!

[KULTULZ]

You're OK ...

The buyer stated to the vendor that he was considering a disc upgrade in the future ($$$) and for now only wanted a boosted split system and instead of the vendor supplying only the correct drum system upgrade sold him a system which is totally unsafe.

HEY! Anytime you see or feel I have posted something incorrect, feel free to correct. I am not proud and learn something new everyday even on older vehicles.

I was starting to have self-doubt there.

[KULTULZ]

Originally Posted by Flattop

What style residual pressure valves (rpv’s) are you using?

Sorry about that.

Inline (after MC) valves. They should be mounted as near the MC as possible.

[V8 Bob]

Originally Posted by KULTULZ

You're OK ...

The buyer stated to the vendor that he was considering a disc upgrade in the future ($$$) and for now only wanted a boosted split system and instead of the vendor supplying only the correct drum system upgrade sold him a system which is totally unsafe.

HEY! Anytime you see or feel I have posted something incorrect, feel free to correct. I am not proud and learn something new everyday even on older vehicles.

I was starting to have self-doubt there.

I have to disagree with you on the system being totally unsafe. The only thing unsafe was the incorrect M/C plumbing, as I pointed out earlier. I would have also included an adjustable proportioning valve with the intent to upgrade the front drums to discs, minimizing additional plumbing changes and costs later on.

As far as the proportioning valve, turning the knob CW to fully open the valve raises the split point about 1000-1200 psi, well above the normal drum brake operating pressures-in effect bypassing any proportioning to the rear drums.

[KULTULZ]

We will have to agree to disagree.

No foul, no harm.

[JeffB2]

Originally Posted by Lamar Wadsworth

Good info, thanks!

Seems like this has gotten a bit off track with responses, and since you are sticking with a drum to drum master cylinder this video may give you a few pointers being that the Mustang drum/drum master is used in our 50's Fords. https://www.youtube.com/watch?v=WeBDLoGQ79Q&t=71s I love this tool ! https://www.harborfreight.com/brake-...der-92924.html So when I did my brakes on my '54 it was about 108 outside in Phoenix and the garage fridge had cold PBR I somehow forgot to do the bench bleed so I thought I would turn on my compressor hook up the tool and give it a shot starting with the passenger side rear bleeder then moving to the drivers side rear and guess what ? No air and a firm pedal in less than 10 minutes went ahead and did the fronts just because all the wheels cylinders were all new and still no air and a firm pedal. A lot of guys will also convert the old Ford troublesome brake sender to a GM style that works off the pedal by fabricating a simple bracket check the 1952-59 Ford Social Group for pictures of those from the members.

[KULTULZ]

Originally Posted by JeffB2

Seems like this has gotten a bit off track with responses...

How has this thread gotten off-track in your opinion?

[JeffB2]

When you start throwing prop valves and residuals into the mix which he doesn't need with a manual dual master for drums it can get confusing for some,just saying. Sometimes the KISS method is best.

[KULTULZ]

What the insertion of that reference was intended to do is warn people of how they can be taken advantage of by unscrupulous and/or un-knowledgeable vendors.

[bobss396]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by JeffB2

When you start throwing prop valves and residuals into the mix which he doesn't need with a manual dual master for drums it can get confusing for some,just saying. Sometimes the KISS method is best.

Very simple works for me. There is no reason for a 65 year old car to have a proportioning valve, a basic brass block does the trick.

[KULTULZ]

Originally Posted by bobss396

There is no reason for a 65 year old car to have a proportioning valve, a basic brass block does the trick.

Are you referring to DRUM/DRUM or DISC/DRUM?

[bobss396]

Originally Posted by KULTULZ

Are you referring to DRUM/DRUM or DISC/DRUM?

Drum-drum for sure. I used a distribution block from Summit with my front disc swap. It has a rear bias adjuster, which I have never had to touch. It runs wide open.

[KULTULZ]

Originally Posted by bobss396

I used a distribution block from Summit with my front disc swap. It has a rear bias adjuster, which I have never had to touch. It runs wide open.

You are referring to what type of 'rear bias adjuster'?

[bobss396]

Originally Posted by KULTULZ

You are referring to what type of 'rear bias adjuster'?

Similar to this one from Summit.

https://www.ebay.com/itm/Adjustable-...8AAOSwmtZfKZiw

[KULTULZ]

Now wait a minute ...

First you say there is no need for a PPV on a car (DRUM/DRUM I a$$-u-me), then you state you only used a distribution block.

Now you are saying you are using an ADJ BIAS VALVE on your DRUM/DRUM fully opened?

You have a DRUM/DRUM DUAL RESERVOIR MC upgrade?

The last photo below is a FORD (Weatherhead) free-standing PDV (Pressure Differential Valve/Distribution Block of the seventies period (no PROPORTIONING/METERING VALVE). If you do not want the WARNING LAMP, don't use the circuit.

EDIT - ONE MORE TIME

Originally Posted by bobss396

Very simple works for me. There is no reason for a 65 year old car to have a proportioning valve, a basic brass block does the trick.

Originally Posted by bobss396

Drum-drum for sure. I used a distribution block from Summit with my front disc swap. It has a rear bias adjuster, which I have never had to touch. It runs wide open.

Are you saying you have an early disc/drum upgrade with no valving on the street?

You know, this why SEMA has to continually fight the FEDS who want to put a stop to owner repair/modifications.

[paul2748]

He said it was wide open

[paul2748]

If you want the skinny on what master to use, go to the experts make and sell conversion parts. Try Engineered Components Inc (ECI) in Conn. for advice. They make all kinds of kits for brake conversions.

[KULTULZ]

Originally Posted by paul2748

He said it was wide open

Who's he and what is wide open?

[KULTULZ]

Originally Posted by paul2748

If you want the skinny on what master to use, go to the experts make and sell conversion parts. Try Engineered Components Inc (ECI) in Conn. for advice. They make all kinds of kits for brake conversions.

Just what is needed, another kit assembler offering GM components for a FORD. Wonder how much of it is off-shore?

That CORVETTE MC goes well with the INTERSTATE BATTERY and STANT radiator cap.

[KULTULZ]

Function and Purpose of the Proportioning Valve

The proportioning valve typically connects the master cylinder to the rest of the braking system, but sometimes it is independent of the cylinder. This valve is necessary for optimizing front-to-rear bias, also referred to as brake balance. It is a spring-loaded component that activates when fluid pressure builds when you step on the brake pedal. Then, the valve’s plunger unseats and fluid rushes into the calibrated range. Once this happens, the spring gets compressed and the plunger blocks the fluid from passing through. Even pressure distribution among the front and rear of your vehicle is important for safe and reliable braking performance.

Signs of a Failing Proportioning Valve -

Just like any other part of your car, the proportioning valve may eventually fail. There are a few different ways to tell this is happening. First, you might notice your car is taking a nose dive when you suddenly apply the brakes. Then your car may not stop fast enough. If your rear wheels lock up easily, especially when you drive on wet surfaces, it is a good sign your proportioning valve is going bad. You can also read about more signs your braking system isn’t functioning properly.

Causes of Valve Failure

If you sense your valve is failing or not operating properly, you might be wondering how this happened. Sometimes proportioning valves simply fail after a long time of driving. Other times, you might have caused the problem by making a modification that impacts your brake balance. Here are some modifications that can influence your front-to-rear bias.

Modifications that can increase front bias:

• Increased diameters of front caliper pistons
• Increased friction of front pad coefficient
• Increased diameter of front rotor
• Decreased diameters of rear caliper pistons
• Decreased friction of rear pad coefficient
• Decreased diameter of rear rotor
• Less sticky tires
• Less weight on the front axle
• A loaded rear axle
• Lowered vehicle causing a lower center of gravity

Modifications that can increase rear bias:

• Increased diameters of rear caliper pistons
• Increased friction of rear pad coefficient
• Increased diameter of rear rotor
• Decreased diameters of front caliper pistons
• Decreased friction of front pad coefficient
• Decreased diameter of front rotor
• More sticky tires
• More weight on the front axle
• An unloaded rear axle
• Raised vehicle causing a higher center of gravity

SOURCE - https://www.sundevilauto.com/what-do...for-my-brakes/

[V8 Bob]

Originally Posted by KULTULZ

SOURCE - https://www.sundevilauto.com/what-do...for-my-brakes/

While most of the above info on proportioning valves is correct, the actual operation is not. Fluid is never "blocked", but is delivered based on the percentage value of the valve once the "crack point" pressure is exceeded.


As for drum brakes, some proportioning could have preceded disc brakes if the earlier D.O.T. brake performance requirements had been much stricter, like those starting in the mid '70s.


A good example of the possible need for a drum prop valve is when using late duo-servo rear drum brakes with obsolete non-servo front drums, something done often with old (pre-'49) Fords.

[KULTULZ]

Originally Posted by V8 Bob

While most of the above info on proportioning valves is correct, the actual operation is not. Fluid is never "blocked", but is delivered based on the percentage value of the valve once the "crack point" pressure is exceeded.

Can we agree on restricted flow as pressure increases at the knee point?

GM did use a PPV on some all drum applications. Makes perfect sense to me. But ABS has changed all of this.

What I am trying to point out is that the ill-conceived notion that an ADJ PPV will correct all situations. That is why they are not approved for the street. Their function is race car only.

Some of these so-called "BRAKE KIT SELLERS" are dangerous (IMO).

INFO SOURCE BELOW - https://www.brakes-shop.com/brakeped...tioning-valves

[V8 Bob]

Originally Posted by KULTULZ

Can we agree on restricted flow as pressure increases at the knee point?
No. The pressure is reduced to a percentage of master cylinder output. Has nothing to do with flow.


GM did use a PPV on some all drum applications. Makes perfect sense to me. But ABS has changed all of this.

What I am trying to point out is that the ill-conceived notion that an ADJ PPV will correct all situations. That is why they are not approved for the street. Their function is race car only.
Using an ADJ PPV may not correct all situations, but is a better alternative to a fixed value PPV designed for an entirely different vehicle and/or brake system. ADJ K/H PPVs were used on some mid-'60s Lincolns/T-Birds---my '32 and '40 both have one. Technically, any non-stock factory brake system or component is probably not "approved". Preventing early rear wheel slide is the important goal, period.



Some of these so-called "BRAKE KIT SELLERS" are dangerous (IMO).
Most have improved their "tech" over the years, although a couple still need improvement. What's more troubling to me is the lack of basic brake system knowledge obvious on most forums, especially dual systems, that have been around for almost 60 years!




INFO SOURCE BELOW - https://www.brakes-shop.com/brakeped...tioning-valves

^^^

[KULTULZ]

Originally Posted by KULTULZ


Can we agree on restricted flow as pressure increases at the knee point?

No. The pressure is reduced to a percentage of master cylinder output. Has nothing to do with flow.

- So a restriction in a hydraulic system will not reduce flow?

What I am trying to point out is that the ill-conceived notion that an ADJ PPV will correct all situations. That is why they are not approved for the street. Their function is race car only.

Using an ADJ PPV may not correct all situations, but is a better alternative to a fixed value PPV designed for an entirely different vehicle and/or brake system.

- You would have to figure out the newly modified braking systems and then apply a PPV to that. The best method is to study an original application and not fall for RACE CAR ONLY SYSTEMS.

ADJ K/H PPVs were used on some mid-'60s Lincolns/T-Birds

- Please give me an exact example. News to me.

Some of these so-called "BRAKE KIT SELLERS" are dangerous (IMO).

Most have improved their "tech" over the years, although a couple still need improvement.

What's more troubling to me is the lack of basic brake system knowledge obvious on most forums, especially dual systems, that have been around for almost 60 years!

- AGREED!

- And most of the advice given is even more puzzling and dangerous.

[V8 Bob]

KULTULZ,


1-There is no brake fluid "flow", only very slight movement. You knew that!


2-"Studying" a modified or custom brake system to match an existing factory system's fixed value PPV doesn't include all the dynamic Hi/Co Lo/Co testing the factory (and I) had to do. I'll stay with, and will continue recommending proven adjustable PPVs thank you.


3-1965-6 Lincolns, T-Birds and Mustangs with front disc brakes. The K/H adjustable valves came in two or three different styles.


4- I hope my advice isn't included in the "puzzling and dangerous" category.

[KULTULZ]

Originally Posted by V8 Bob

KULTULZ,

1-There is no brake fluid "flow", only very slight movement. You knew that!

Liquid in motion is a flow.

2-"Studying" a modified or custom brake system to match an existing factory system's fixed value PPV doesn't include all the dynamic Hi/Co Lo/Co testing the factory (and I) had to do. I'll stay with, and will continue recommending proven adjustable PPVs thank you.

You can't quite grab the concept. Production braking systems. Sit up a little higher.

And, you can use/recommend anything you like. Doesn't make it correct or legal, just (IMO) unless you have a FLUID DYNAMICS DIPLOMA and work for a major car company.

3-1965-6 Lincolns, T-Birds and Mustangs with front disc brakes. The K/H adjustable valves came in two or three different styles.

Let me ask again, how are they adjustable?

4- I hope my advice isn't included in the "puzzling and dangerous" category.

I don't take it as advice. You may, but I find it skeptical.

[V8 Bob]

Have a nice day.

[KULTULZ]

Originally Posted by V8 Bob

Have a nice day.

You too BOB ...

I am really disappointed though that you won't share with me the secret of how the KH PPV (2091) was adjustable. I bet those SHELBY BOYS would just love to gain that little secret.

And, it surely would be better than 'SPINNING FOR DOLLARS' (read INCREASED INSURANCE PREMIUMS) with the so-called ADJ PPV, for which there is no real ADJ, only wild guessing without knowledgeable brake spec, pressure gauges and a suitable skid pad. And even then, there is no guarantee it will perform as described.


You know, I bet that IS the reason WILDWOOD inserted that WARNING and DISCLAIMER, that being they know too it is meant for RACE CAR and not STREET CAR but would hate to lose the sales.


... sigh ... oh well ...

[Jwawhite]

I think I'll stay with the single reservoir MC drum brakes..........

[KULTULZ]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Jwawhite

I think I'll stay with the single reservoir MC drum brakes..........

It is really not that big of a deal if one ciphers and strategizes carefully.

Stay away from VENDOR CANDY and you should be OK.

[JeffB2]

Originally Posted by Lamar Wadsworth

Need to replace the master cylinder on my '55 Ford. Keeping stock drum brakes. Is there any particular late '60s-early '70s dual chamber MC for drum brakes that someone can recommend that you have used in this application? I think dual chamber MCs became standard on everything around '66 or '67. I remember a '69 Dodge A-100 van and a '72 Ford pickup I had both had dual chamber MC, drum brakes all around, and no power booster. Wondering if one of those might work, or something for a mid-size Ford car of that vintage? I can do the brake line plumbing to separate front and rear brakes. I know Rambler was the first to have that feature in the early '60s.

I used these to connect the front and rear lines and eliminated the old three way down by the frame that way you just need one 1/4 to 3/16 adapter and one 20" x 3/16" brake line.

[Dobie Gillis]

A late '60's/early 70's Malibu drum/drum master is a near bolt on, may need to drill 1 hole in the firewall. Any dual master you get will make your pushrod a tad short, but adjustable length pushrods are available.

[KULTULZ]

Originally Posted by Dobie Gillis

A late '60's/early 70's Malibu drum/drum master is a near bolt on, may need to drill 1 hole in the firewall.

Not intending to start another food fight, but ...

Why would anyone want to use a GM MC on a FORD?

Wondering In W(BY GOD)V...

[Dobie Gillis]

It was what was immediately available locally when I needed one. It worked just fine and is still working just fine per the guy I sold the car to. Improvisation is the very soul of hot rodding.

[KULTULZ]

Originally Posted by Dobie Gillis

Improvisation is the very soul of hot rodding.

Yeah, you see it in CUBA a lot also ...

[JeffB2]

Originally Posted by KULTULZ

Not intending to start another food fight, but ...

Why would anyone want to use a GM MC on a FORD?

Wondering In W(BY GOD)V...

Over the years and it still will show up on Ebay and other forums as "Corvette" master cylinder I guess calling it that makes it sound better.

[KULTULZ]

Originally Posted by JeffB2

Over the years and it still will show up on Ebay and other forums as "Corvette" master cylinder I guess calling it that makes it sound better.

I think I have it figured out. It is known as the ROBERT MITCHUM SYNDROME, that being an inordinate fear of not being able to keep the car under control on a two-lane, subsequently sliding into a power sub-station and then having to go to TRAFFIC SCHOOL.

What that CORVETTE STYLE ROAD RACING MC gives is confidence in the driver's ability to stab and steer so that the next time he won't go off the road.

Much less, it looks good with the DIALING FOR DOLLARS supposed PPV, the INTERSTATE BATTERY, STANT radiator cap (with pull tab) and of course the ever popular EDEL CHI-COM ACL with foam insert that lights up with every backfire.

OH! I forgot, also yellow plug wires and a HEI distributor cap. Pop the hood on that baby and all that will set the gang wowing.

[40 Deluxe]

Originally Posted by KULTULZ

Sorry about that.

Inline (after MC) valves. They should be mounted as near the MC as possible.

Hmmm, need to tell this to Mercury. My '67 Cougar with factory front discs had the residual check valve mounted on the floor pan directly above the rear axle! (I removed it when installing a new master with a built-in valve.)

[KULTULZ]

Originally Posted by 40 Deluxe

Hmmm, need to tell this to Mercury.

My '67 Cougar with factory front discs had the residual check valve mounted on the floor pan directly above the rear axle! (I removed it when installing a new master with a built-in valve.)

Maybe tell MERC you need a SHOP MANUAL. The valve you are referring to was the PROPORTIONING VALVE (2B091). The RESIDUAL VALVE was in the MC DRUM CIRCUIT OUTLET.

[paul2748]

I thought that when Ford went to discs in the front they used a combination valve ( Proportioning and residual pressure) and no master for disc/drum setups had a residual pressure valve. Or maybe they came later???

[KULTULZ]

No true COMBINATION VALVE until 1971/72. They were separate before that model run.

[40 Deluxe]

Originally Posted by KULTULZ

Maybe tell MERC you need a SHOP MANUAL. The valve you are referring to was the PROPORTIONING VALVE (2B091). The RESIDUAL VALVE was in the MC DRUM CIRCUIT OUTLET.

Oops! See the egg on my face? Apparently I've been wrong all these years. My bad!

[KULTULZ]

Originally Posted by 40 Deluxe

Oops! See the egg on my face? Apparently I've been wrong all these years. My bad!

Nah, you're OK. Brake valving is a fairly complicated subject, especially considering all the different circuit designs used.

The question is, do you have a PPV on your new system? And did the replacement MC come with an internal PRV and how was the new system was plumbed?

[40 Deluxe]

Originally Posted by KULTULZ

Nah, you're OK. Brake valving is a fairly complicated subject, especially considering all the different circuit designs used.

The question is, do you have a PPV on your new system? And did the replacement MC come with an internal PRV and how was the new system was plumbed?

Well, the new master has internal residual valve for the rear, but no proportioning valve in the system. I have a 9" rear out of a '59 Galaxie which has smaller brake shoes than the original Cougar shoes. I get on the brakes fairly hard after a 110 MPH run down the strip and braking action feels fine; no tendency to swap ends.

[KULTULZ]

Originally Posted by 40 Deluxe

Well, the new master has internal residual valve for the rear, but no proportioning valve in the system.

I have a 9" rear out of a '59 Galaxie which has smaller brake shoes than the original Cougar shoes. I get on the brakes fairly hard after a 110 MPH run down the strip and braking action feels fine; no tendency to swap ends.

How did the car come through, with a SB or FE? It had KH 4 PISTON DISC on the front? 8" rear assy?

If the rear shoes are smaller (you would have to cipher swept area) it may explain the not needing a PPV. It is not supplying the braking force as OEM design. Is this a strip or street/strip car?

But then again, you have never had to dynamite the brakes if someone runs a red light in front of you on a slick road surface ...

[40 Deluxe]

Originally Posted by KULTULZ

How did the car come through, with a SB or FE? It had KH 4 PISTON DISC on the front? 8" rear assy?

If the rear shoes are smaller (you would have to cipher swept area) it may explain the not needing a PPV. It is not supplying the braking force as OEM design. Is this a strip or street/strip car?

But then again, you have never had to dynamite the brakes if someone runs a red light in front of you on a slick road surface ...

It's still the original 289 (well, the crank and block are). The calipers are the 4 piston and the original rear was the 8". Currently it's only run at the strip. And true, I haven't made a panic stop on a slick road. it could get hairy, especially with drag radials with minimal tread (they are DOT legal for use on public roads!).

[KULTULZ]

THANX! for the info, appreciate it.

[KULTULZ]

Originally Posted by KULTULZ

The period DUAL RESERVOIR MC(s) you want are 1967-1973 FORD INTERMEDIATE (FAIRLANE-MUSTANG)

CORRECTION - It seems FORD deleted the RPV in their MC after the 1971 model run.

DRUM/DRUM and DISC/DRUM are included for availability I had the chart (from the 1965/1972 MPC), that shows application, manual/power and bore size. The text would also include info regarding the valving used in the period.

I have a current computer problem(s) and will post that info as soon as I can.

If you buy a current production replacement MC, it will most likely not have the RPV(s) in the outlet circuits. You will have to plumb inline valves.

Below are the chart(s) for the 1967-1971 dual reservoir MC (application and bore size) (FAIRLANE - MUSTANG). They originally came with the RPV(s) installed. The valves were not available from FORD separately for service but were included in their MC overhaul kits.

Any current new service replacement (or possibly rebuild) will most likely not have this valve(s) installed.

[1oldtimer]

Jumping in late. Use something size to original and use 2 #10 res valves (I use SSSB, since Wilwood and others leak), after you check and make sure new master has no residual valves inside. My '47 I used a mid/late 60's Chrysler with a home made mount and pushrod extension (use stock rod) and my '28 had a late 60's AMC/Jeep master with home made adapter. The '47 had a 1 1/16 Bore and the new master has a 1" bore, all other parts are stock.