Hello people,
I have just taken a look (and some pictures) at restoring my pedal box and everything that is attached to it.
This caught my eye and I am wondering how many problems you guys see.
I have not touched anything yet at the moment I took this picture, just took it out of the car few years ago and today put it on a stand to start the restoration.
Meanwhile I know I'm in need of a new brake master cylinder, what is the recent status on OE replacement?
Jochen
Replies sorted oldest to newest
The dust boot is missing on the clutch master. The retaining clip and washer for the gas pedal are absent. It looks like you do not have the clutch effort reduction systems and that's one less thing to worry about. Overall it looks healthy. I can't comment on the reproduction OE brake master cylinders since I am using the Ford master along with an adapter.
Do you know the bore diameter of the stock style master?
23 mm, anothers links for the same brake master cylinder :
* 308 / 328 / Mondial Brake Master Cylinder -133576 23mm | AW Italian Auto Parts
I have found mine to be 25.4mm.......
Wow Steve, that looks neat. In some time mine will look like that too, with some modifications. ;-)
The clutch master dust boot is missing because they added a spring there since the original spring was broken in its place.
And what do you think of the solution for the missing clips at the brake pedal to the booster?
Love the ziptie holding the pin into the brake booster shaft! ''
Ron
"The clutch master dust boot is missing because they added a spring there since the original spring was broken in its place."
That spring belongs there, and there is a dust boot available as a part of a rebuild kit that fits perfectly.
Someone here helped me locate it. I'll look.
Here it is on Ebay. The dust boot is the only part you can use, the rest is not simpatico. Too small.
when do you say 25.4 mm is for the mustang one ? because, if I do not make mistake, the original pantera was a bentitalia brake master with a bore diameter of 22 mm on the first versions and 23 mm on the last ones. on my 79 euro GTS I had a 23 mm bore.
"I have found mine to be 25.4mm......."
That's an even inch. The ford and chevy masters that I have seen adapted are, I think, 15/16", or about 24mm, and the stock appearing style master is 23mm.
Is there an optimum size or is it about personal preference? Either the shorter throw and harder pedal of a larger bore, or easier pedal, but longer throw from the hydraulic advantage of a smaller bore?
@larryw posted:"The clutch master dust boot is missing because they added a spring there since the original spring was broken in its place."
That spring belongs there, and there is a dust boot available as a part of a rebuild kit that fits perfectly.
Someone here helped me locate it. I'll look.
Here it is on Ebay. The dust boot is the only part you can use, the rest is not simpatico. Too small.
Oh, my mistake, I thought (how could that be) that it was a work around solution for the broken spring at the clutch arm.
@dipascale posted:when do you say 25.4 mm is for the mustang one ? because, if I do not make mistake, the original pantera was a bentitalia brake master with a bore diameter of 22 mm on the first versions and 23 mm on the last ones. on my 79 euro GTS I had a 23 mm bore.
I will measure again tomorrow.
Confirmed it is 25.4mm ergo 1". 
@larryw posted:"I have found mine to be 25.4mm......."
That's an even inch. The ford and chevy masters that I have seen adapted are, I think, 15/16", or about 24mm, and the stock appearing style master is 23mm.
Is there an optimum size or is it about personal preference? Either the shorter throw and harder pedal of a larger bore, or easier pedal, but longer throw from the hydraulic advantage of a smaller bore?
I have both. As far as preference, I don't like the 1 1/8". There is less progression, and the pedal is much harder.
"I have both. As far as preference, I don't like the 1 1/8". There is less progression, and the pedal is much harder."
Other than the master cylinder bore diameters, are both cars otherwise set up with stock or similar calipers?
If I did the math right, bore area of the 1-1/8" master is just about 1 square inch, and the area of the 22mm (7/8") master is about .60 square inches. A pedal throw of 2" with the larger master, would become 3.33" with the smallest. That is pretty significant. No wonder the hard pedal.
The 15/16" bore would require a 2.89" pedal throw to move the same volume of fluid, that is close enough to the 22mm bore throw (and easier pedal) for me.
Everything is the same, stock setups. 22mm is pretty small. 23-24 is what I would shoot for if you want the feel of a modern day car.
The size of the bore effects the effort needed to the pedal.
The Mustang varies, depending on application from 7/8" to 1" in 1/16" increments.
By far the most common application is 7/8" as it is the easiest to operate.
Here in the US, the aftermarket is going to deal with SAE dimensions and many are using Ford Mustang masters (with adapters) as aftermarket replacements for the original Euro metric units so I refer to them for that reason.
Where you start to change the piston diameter is when you go racing.
I have gone through an entire step by step trial of each BY 1/16" INCREMENTS and can tell you the results. The ones I skip here are insignificant.
The 1-1/8" first came to light in the Boss 302 chassis modification booklet prepared by Ford.
It was used when you went to fully manual brakes, with the 67 Thunderbird front calipers and adding rear disc brakes.
Under that circumstance, it works fine. What happens is that it reduces the pedal travel and also the ability to fully lock up the brakes.
When you go back to a more standard brake arrangement WITH POWER BOOST ASSIST you can't operate the pedal.
The original application of the 1-1/8" is from a Ford truck.
The advice from me on this size is stay away from it.
The standard 6 cylinder bore is 7/8". That is the one with the least effort BUT has the largest ability to lock the brakes up in a panic stop. You don't want that in a performance application. PERIOD,
The 15/16" is the one that you are going to find in the factory performance packages and the Pantera. They are a compromise between effort and anti-lockup potential.
The replacement Master that I got from Hall, is an aluminum Ford Mustang unit (polished with the Hall 'bling') and is 15/16". It's fine.
My 68 GT350 is set at 1" (25.4mm) and is fine for the bigger then stock (68 Trans Am legal, 4 piston calipers, 1.25" thick vented rotors, 12" diameter rotors, rear disc brakes). As Kar Kraft put it, "they were designed to stop a 7,000 pound car. in a 3,000 pound car, they are fantastic".
I did just put those brakes on my Pantera and suspect that I MAY need to go to a 1" bore master to reduce lock up tendency but can't answer that one yet. That has not been determined if a change is needed there.
So the 15/16" master = 23.8mm which I would substitute a 24mm master as a stock replacement.
Forget about using the 1-1/8. You won't be able to move the brake pedal to stop the car. Don't waste your time with it.
The largest that you should attempt to apply in my view is the 1" of which there is no metric equivalent at 25.4mm. The 24mm should be what you want on a street car.
Thanks for the insights and knowledge.
Since I am going for non original calipers, and I have the donor master brake cylinder, I was happy to find that the bore of the master cylinder that is on my Pantera is the same as the donor's.
But I will have to find a replacement since the bore is pitted. I am investigating if the master of a Ferrari 400 can be used.
@brickdrifter posted:Thanks for the insights and knowledge.
Since I am going for non original calipers, and I have the donor master brake cylinder, I was happy to find that the bore of the master cylinder that is on my Pantera is the same as the donor's.
But I will have to find a replacement since the bore is pitted. I am investigating if the master of a Ferrari 400 can be used.
I suppose that each of us has their own reasons for proceeding in a specific direction or even starting at one?
The point on using Ford sourced, even at the aftermarket level, is for the variety available now and in the future and the economy of that source.
Why pick something expensive and elusive like a Ferrari part when there are equal if not better choices available?
Of course part of the choice also has to be where you feel most comfortable and that also has to do with your knowledge base and familiarity with the product.
Mine is with Ford parts. Yours may be Ferrari? I understand that.
I haven't worked with metric units and just the switch to that system may give you finer tuning ability?
Ford parts are a option I am considering Doug. Need the adapter for that.
What I notice is that most after market master cylinders are not with a plastic container. Belgian tech inspection demands that fluid level has to be seen from outside. I know, silly people, but that is the way it is.
I agree that where you are located is a significant factor in selecting replacement parts.
I know that Roland Jackel was an original parts source in Europe but am not sure if he sold his parts business and if so to whom?
I don't recall seeing any of the US Pantera parts vendors offering original equipment master cylinders but I think that you need to make the rounds with that.
I would also start inquiring if your original is rebuild able locally. Most are if you can get the parts and there is a rebuilder here that can sleeve the original with a stainless steel insert.
Isn't at least the initial sizing of the master cylinder bore actually about maintaining a certain ratio of the master piston to the slaves?
On a stock Pantera there are four 1.685" (43mm) diameter rear pistons, and up front we have two more at 1.685" and two at 1.335" (34mm). If I did the math right, that comes to 16.18 square inches of slave pistons. Figuring the ratios by using the master piston diameters we've discussed, it comes out to a 18.49:1 ratio for the 7/8" (22mm), 17.26:1 for the 15/16" (24mm), 16.18:1 for the 1" and 14.38:1 for the 1 1/8".
So, before committing to a certain size master, probably best to know the piston areas of the calipers you will be using. If your total slave piston area rises to around 19.4 square inches, you may want that 1 1/8" master to maintain the stock pedal feel of a Pantera. Or am I way off course with this?
"Belgian tech inspection demands that fluid level has to be seen from outside."
Could you drill and tap holes in the side of a Ford master and install something like Holley carburetor bowl fuel level sight glasses to see the fluid level from outside?
Hey Larry,
you are right that the bore(s) of the master should match the calipers. That is why there are some staggered masters out there. Bigger bore for the front calipers and smaller one for the rears.
That said, I have the calipers and the master cylinder of the donor car and the master has a 1" bore for front and rear calipers. I have driven a car with those brakes and they are awesome (donor car weighs 3500lbs) That is why I was happy to find that on my Pantera the master was also a 1" bore. But as said, it needs replacing or at least a sleeve. I think the pitting is too deep for a simple hone.
Your sight glass idea is a good one, worth considering. ;-)
Thanks, Jochen
Belgian tech inspection demands that fluid level has to be seen from outside. I know, silly people, but that is the way it is.
never heard of this Belgian , (EU) rule , all the USA build classic cars have cast steel reservoirs .never hear of it was a problem.
7102 tips the scales at 3,300 pounds with a half tank of fuel and me in the front seat. Pretty close match.
@larryw posted:Isn't at least the initial sizing of the master cylinder bore actually about maintaining a certain ratio of the master piston to the slaves?
On a stock Pantera there are four 1.685" (43mm) diameter rear pistons, and up front we have two more at 1.685" and two at 1.335" (34mm). If I did the math right, that comes to 16.18 square inches of slave pistons. Figuring the ratios by using the master piston diameters we've discussed, it comes out to a 18.49:1 ratio for the 7/8" (22mm), 17.26:1 for the 15/16" (24mm), 16.18:1 for the 1" and 14.38:1 for the 1 1/8".
So, before committing to a certain size master, probably best to know the piston areas of the calipers you will be using. If your total slave piston area rises to around 19.4 square inches, you may want that 1 1/8" master to maintain the stock pedal feel of a Pantera. Or am I way off course with this?
Generally speaking, no, the size of the pistons in the calipers is not in direct proportion to the size of the master.
In a vehicle of constant weight and brake pedal leverage, changing the bore of the master only effects the brake pedal effort.
Here, you are only considering three possible bore sizes, 7/8", 15/16" and 1" (and their metric equivalents).
7/8" bore will give you more pressure and tend to lock up the brakes. 1" will reduce the tendency of brake lock up at the expense of more pedal effort.
You do not reduce the pressure to the rear brakes by using a master with two different bores. You use the same bore for front and back and reduce the pressure to the rear with an inline pressure reducing valve, i.e., proportioning valve.
Sometimes (with Girlings) and currently with Brembos and some Wilwoods, the size of the pistons in the calipers are staggered just in order to fit the pistons into a "modular" caliper system.
The original Girlings in the Pantera fronts are two different sizes but we don't know the entire reason that the development engineer had.
It could simply be that they were looking for more even brake pad wear. When you alter the size of the caliper piston, you modify the pressure that the brake pad is receiving immediately under the piston.
The larger the piston, the greater surface area receiving pressure from the piston.
There, the larger the pad, the larger the piston area necessary.
Conversely, when you go to a larger surface area on the pad, the larger the piston that you need.
Because you are attempting to get predictable results it is better if you use the same size caliper pistons throughout. Changing that MAY alter the clamping force of the pads un-uniformly.
The size of the master bore in millimeters is LIKELY going to wind up at 24mm after extensive testing of other combinations.
In order to get BETTER braking on the Pantera, you need a larger diameter rotor, 12"od with 15" Campi's, a larger surface area brake pad, and a four piston Caliper with piston od's complimentary to those pads and rotors.
A pad formulation of something equivalent to a Porterfield R4S will also increase braking ability and reduce fade due to heat build up.
Vented, slotted and drilled rotors at this point also help reducing brake temps (documented by lab testing) 200F degrees.
Brake line sizes also come into play here. The stock Pantera lines are equivelent to a JIC -3 size. If you enlarge the system to a -4 (1/4"SAE) you are increasing the volume to the calipers but are reducing the pressure to them.
For a street car, leave the size of the lines alone at a -3 and leave the rear brakes alone, with the possible exception of going to a vented rotor LIKE the '65 Mustang rotor.
The rear doesn't need more braking (generally speaking) and you run the risk of not being able to balance the lockup front to rear.
Now if you are seriously going to race this car, then you probably aren't going to be restricted by the size of the braking system caused by 15" Campi's and you just need to do some very serious and expensive development work on the brakes.
I didn't do any testing of the original master cylinder with bigger front brakes but I suspect that you will be opening a can of worms with that if you change out the stock Girlings for a larger system.
If I were you, I'd talk to Chris over at SAAC Restorations and see what he recommends considering your "Belgian restrictions" of a translucent reservoir. Either that or move out of Belgium.
Other Pantera shops with EXTENSIVE big brake solutions are going to be Larry Stock at Pantera Parts, Mike Cook, formally of Hall Pantera (where you can find him, I can't) and Pantera Parts in Colorado. They likely will be similar to me in suggesting US solutions rather then the European ones that are out there too.
I'm sorry if I make this sound confusing but there are several interacting factors involved in modifying stock brakes on a Pantera and if you DON'T want to get killed, you NEED to know WTF you are doing with them. There are pitfalls all over the place and a novice is going to be blind to many.
One of the DESIRED features looked for in "bigger brakes" is REDUCING the tendency of locking them up. You WILL get that with a 1" bore and larger rotor/caliper/pad area solution.
One last consideration here though is in order to get more braking, you need more tire patch area and better grip, i.e., coefficient of friction to the rubber.
Remember the original front tire was a 185-78-15 and that contact patch was part of the brake selection consideration.
A dry race tire is going to be a completely different animal and a street car with fantastic brakes may be a "disaster" with race tires on it.
WHATEVER you do in Belgium DO NOT tell them that the brakes are not stock. What's the Italian expression? Morto bene? "Good and dead"?
"Here, you are only considering three possible bore sizes, 7/8", 15/16" and 1" (and their metric equivalents)."
Actually, if you take another look, I considered the four bore sizes mentioned within the posts and figured the ratios for each.
"7/8" bore will give you more pressure and tend to lock up the brakes. 1" will reduce the tendency of brake lock up."
And will yield a much higher pedal effort, even higher if you used the 1 1/8" master. That's the ratio thing. If the larger masters were acting against proportionally larger larger slave bore areas, I believe the pedal effort would remain the same.
"You do not reduce the presure to the rear brakes by using a master with two different bores. You use the same bore for front and back and reduce the pressure to the rear with an inline pressure reducing valve, i.e., proportioning valve."
Except Pantera proportioning valves do it by reducing pressure to the front.
A stepped master will invariably reduce the rear master bore, as it is the deep inner piston. The closing of the masters internal feed ports as the master piston advances under pedal pressure will result in inadequate volume to the rear circuit necessary to take up the slack and build real pressure at the rear pad/rotor interface.
"Brake line sizes also come into play here. The stock Pantera lines are equivelent to a JIC -3 size. If you enlarge the system to a -4 (1/4"SAE) you are increasing the volume to the calipers but are reducing the pressure to them."
This doesn't seem accurate. It's physics. Once those lines (consider it a closed vessel) are filled with fluid and free of any compressible component (air), once the pedal is applied, the pressure everywhere within that vessel is the same, no matter the diameter, no matter where you measure it. That's kind of a rule.
The only variable is a potential for larger diameter flexible lines, particularly stock hoses, to expand more than smaller ones, slightly increasing the amount of fluid that would need to be moved to make the same line pressure. But since at this point, the master piston has already advanced past the feed ports and closed them, no additional fluid can be introduced to make up for the swell of the hoses except more pedal travel to move more fluid.
After looking here: https://www.joesracing.com/master-cylinder-math/ I see I considered the acting slave piston area incorrectly, but the premise of maintaining the right master/slave piston size ratios is pretty obvious.
Enough for me on this subject.
@simon posted:never heard of this Belgian , (EU) rule , all the USA build classic cars have cast steel reservoirs .never hear of it was a problem.
Simon, not a EU rule, only BE. Since the new laws for the Oldtimer cars. And depends which controller you have. :-(
Op dit moment echt klote hier.
And how about the classic US build cars ?
they all have cast iron fluid reservoirs whit integrated master cylinders.
But original the Pantera's have plastic reservoirs where you can see the level.
maybe that the difference , I am not a fan of the aftermarket Mustang Brake masters on Pantera's , it's a very cheap solution on an expensive car.
remeber now that stainless breated brake lines are in the past also not alowed on classic cars in Belgium, but now it's not a problem.
Agree whit you thats depends on the controller , but when you ask where it's writed into the rules they maybe not can show you this rule.
always be carefull when you get brutal,but sometimes it's the only way to get your right.
Simon
