Master Cylinder Questions

[KULTULZ]

KULTULZ........I looked back in this thread to see if this "2B091 Valve" is mentioned, and I didn't see that reference, so I can't answer that question.

Again, my mistake. 2B091 is the BASIC PN on the part (in this case a brake valve), whether ENG, ASSY or SVC. If you notice on the valving you showed, the middle characters is the BASIC PN, which in this case is 2B091. The characters before are the PN PREFIX, the characters following are the PN SUFFIX.

[KYBlueOval]

I went by a Ford dealer yesterday to get the VIN#'s decoded, and here is what I found:

2003 Mustang GT was the donor vehicle for the HydroBoost. It had Traction Control,ABS, and Disc/Disc. When I purchased a replacement MC for this HydroBoost I bought one for a NON traction control car, as my Ranchero does not have traction control.FYI when buying the replacement MC, the only option/question was, with or without Traction Control. Was that a mistake?

2003 V6 Mustang was the donor car for the "2B091 Valve" that is pictured early in this post. It had Disc/Disc, it did NOT have Traction Control ,and did NOT have ABS.

So, with this information, will these parts go together and "like one another"? Or are there other parts that will make for a better system? And what is your opinion of using DOT 5 Silicone Brake Fluid ?

Again, thank you for your interest in this issue, I do appreciate it!
John

[Ford Blue blood]

John Dot 5 is good stuff.  The folks that restore exotics and rare automobiles swear by it. If you plan on short trips and long rest periods for the car it is perfect.  I have never used it because of the cost and some idiosyncrasies I have heard about it.  Can't shake the can?  If you try to replace Dot 3 or 4 with it every rubber item in the system must be replaced?  The pedal never gets a "hard" feel like Dot 3&4?  Old wives tales?

[KYBlueOval]

Bill, Thank you for your input. I asked the question because "KULTULZ" really know his stuff when it comes to Fords and Ford parts, and he might know if there was an issue with using Silicone with the parts I plan to use.
I have Dot 5 in my 2 other cars and it has been in them for many years, without any issues.
John

[KULTULZ]

!!! DO NOT USE DOT 5 FOR A STREET CAR !!!

We can get into that discussion later.

Let's get this one straightened out first and then we can food fight that one out ... 

[KULTULZ]

!!! DO NOT USE DOT 5 FOR A STREET CAR !!!

We can get into that discussion later.

OK... Let me fire the first shot -

DOT 5 doesn't absorb moisture, so some folks think it is the better choice, but is it?  Before you go rushing off to the parts counter, remember even though DOT 5 doesn't absorb water, it can't/won't prevent moisture from entering the brake system.  And since the water isn't absorbed by DOT 5, moisture puddles and causes localized corrosion within the brake system.  As funny as it sounds, DOT 3, 4, and 5.1 absorb moisture, which in turn eliminates the puddling that can cause corrosion.

 More importantly, when brake fluid heats up, water trapped inside the brake lines (but not absorbed by the brake fluid) is converted from liquid to vapor.  Steam compresses easier than liquid.  With this in mind, imagine barreling down the road at high speed and hitting the brakes.  When the hydraulics sends DOT 5 fluid through a pocket of steam in the line, that drop in pressure creates a soft pedal.

SOURCE - https://techtalk.mpbrakes.com/brake-fluid/can-i-use-dot-5

[KULTULZ]

John Dot 5 is good stuff.  The folks that restore exotics and rare automobiles swear by it. If you plan on short trips and long rest periods for the car it is perfect.  I have never used it because of the cost and some idiosyncrasies I have heard about it.  Can't shake the can?  If you try to replace Dot 3 or 4 with it every rubber item in the system must be replaced?  The pedal never gets a "hard" feel like Dot 3&4?  Old wives tales?

No, all are true. If one wants the benefits of DOT 5 without the drama, research DOT 5.1.

It is not performance restorers are looking for, but paint protection if one gets sloppy. It will aerate and leave one with spongy brakes, if not complete failure.

It does not absorb outside moisture as does regular fluid (hygroscopic) but moisture/water does get into the system as it does in any system. That water will find it's way to the lowest points in the hydraulic system, pool and begin to eat.

Regular brake fluid needs to be changed at a minimum of every two years. That rids the system of any moisture before it does damage (the moisture is suspended in the brake fluid).

What is not explained is that most ( the sharp ones) that use this fluid for classics usually have to flush the system completely before driving the vehicle after a long storage.

[KULTULZ]

For anyone contemplating a late model DISC CONV on an earlier car -

The correct YEAR WORKSHOP MANUAL for the donor car is invaluable to understand how all of this plumbing works.

In lieu (Fr.) of a WSM purchase ($$$), one can go the the PARTS DEPT and see if the counter dude will print out an ILL of the braking system for the exact donor car (both brake and booster install), and PARTS TEXT PN printout of the MC and PPV sections. Without this exact info, it is all guess work.

This is much different from a 60/70's conversion. DISC/DISC would not have either a METERING VALVE or RESIDUAL PRESSURE VALVE. The PDV may be integral to the MC. The OEM PPV cannot be used as the rear disc in this example (57 FORD - rear disc from another application other than donor MUST FIS) is from a different vehicle and the valve is calibrated for the original build (2003 MUST DISC/DISC non-ABS). An adj PPV is the fall back option.

Of course detailed photos of the system from the donor would be invaluable.

This is an interesting discussion as in the old days ...  ... the system from an early LINC was used.

[KULTULZ]

I purchased a replacement MC for this HydroBoost I bought one for a NON traction control car, as my Ranchero does not have traction control.

TRACTION CONTROL is an extension of ABS. ESC (ELECTRONIC STABILITY CONTROL is a move forward from T/C).

As long as the MC you bought is for a 2003 MUST (to match FRT CALIPER PISTON(s) SIZE (same calibration) (non-ABS - T/C). The difference in rear disc (not being from the 2003 MUST donor) will be regulated by the ADJ PPV.

[terry_208]

As long as the MC you bought is for a 2003 MUST (to match FRT CALIPER PISTON(s) SIZE (same calibration) (non-ABS - T/C). The difference in rear disc (not being from the 2003 MUST donor) will be regulated by the ADJ PPV.

If I'm reading this correctly, a proportion valve will adjust for a mismatch between the brakes and MC.  If that is correct, could one also correct a mismatch between the mc and the front brakes? 

I'm asking bc I also have a mismatch in the front which came from a non-pb vehicle.  Would the hydroboost over power the mc from that vehicle?

John, sorry for the hijack.

[KULTULZ]

If I'm reading this correctly, a proportion valve will adjust for a mismatch between the brakes and MC.  If that is correct, could one also correct a mismatch between the mc and the front brakes?

No. When you do a conversion, you want to, if possible, match the front caliper piston(s) size/swept volume with the same donor vehicle MC. That is a factory designed match.

The rear bias (DISC/DISC) (different sizes from OEM) can somewhat be overcome with an ADJ PPV if using other than donor DISC/DISC - DISC/DRUM rear bake assemblies. 

I'm asking bc I also have a mismatch in the front which came from a non-pb vehicle.  Would the hydroboost over power the mc from that vehicle?

Are you describing the caliper piston or MC bore size?

If you are going to POWER ASSIST with a donor MC without POWER ASSIST, you most likely will have to source the matching PB MC for the front calipers with power assist. There is a MC DESIGN for manual, power, DISC/DRUM or DISC/DISC.

While there are rules concerning MC piston/bore size to PB, some drivers will appreciate a harder pedal while some want more assist (MC piston size). And don't forget pedal ratio. This should be the first consideration for the upgrade.

HYDRO-BOOST is going to give the best line pressure, depending if the PS PUMP OUTPUT PRESSURE is adequate for whatever HYDRO-BOOST system you choose.

Hope that made sense. If not, hit again.

Remember, an ADJ PPV is not a true PPV. It only begins to control rear pressure at the knee-point cut-in (brake fluid pressure cut-in). It offers no slope after cut-in as does a true PPV. It's something you have to remember and to make the correct initial adjustment. There is really no other choice as a special PPV would have to be calibrated for every possible application.

It helps to state what you are working on and whether kit or donor

[terry_208]

Are you describing the caliper piston or MC bore size?

It helps to state what you are working on and whether kit or donor

I have a mix of donor parts/pieces.  Spindles, calipers, and rotors are from 74 Maverick (I also have on hand the manual mc from same), Hydroboost and mc from 99 Mustang GT and am planning to replace the stock rear drums of the 57 with parts from a Crown Victoria/Marque.

Seems like I have a box of problems, doesn't it?

[gasman826]

I have done the Granada style front disc swap ('74 Maverick should be the same caliper) with hydraulic booster and rear Crown Vic/Explorer disc on two '57s.  Both cars used the '57 OEM manual brake pedal and the original hole (the ratio is correct).  Using the '57 manual pedal, I set the pedal height at the same height as manual brakes and the same as the clutch pedal.  I am assuming you also have power steering.  The hydraulic boosters will not work correctly without PS!  One '57 had booster and MC from a Mustang GT.  The other '57 had a '75 Lincoln donor.  I saw no difference.  The Mustang MC was metric and aluminum which made it prettier.  The Lincoln ugly iron MC worked fine but it was later changed out because it was...ugly.  Both cars had Wilwood adjustable bias valves and both were cranked in as far as they would go leading me to believe they were a waste of money...at least they are not real expensive...better to have and not need than...you know.  Fixed bias is a joke.  So many things enter into adjusting front to rear bias.  Springs, load, road surface, tire sizes, more and more.  What works for me may or may not for you.  I'm just sharing what I've done.

I am gathering parts to convert to four wheel disc this winter.  This time, donor cars and time to search for donor cars has gotten short and valuable.  The plan is for a hydraulic booster (will really help with valve cover clearance) and I still have one in my hoarder pile.  A 1" Wilwood MC and six piston Wilwood conversion kit on the front and with Crown Vic disc on the rear.  This time I am going with Wilwood's combo adjustable proportioning/isolation valve. 

I forgot all three cars have line locks just for fun!

[KULTULZ]

A picture is worth a thousand words.........Here is what I have. I don't see anything that "divides" the MC. Having said that, the larger volume/area of the MC is in the rear. So If I had to guess,the rear circuit is for the front brakes. Just a guess.

This overshot my ears, I need to sit up a little better ...

The reason for the reservoir to appear tilted as it is to compensate for a MC that winds up mounted non-horizontally. The actual fluid level stays level to fill either MC piston chamber.

You have to keep an eye on the fluid level because as the pads wear, there is quicker fluid drop (compared to a drum MC) because of caliper piston/bore size.

Any style MC reservoir(s) must be level at final install.

[KULTULZ]

I have a mix of donor parts/pieces. Spindles, calipers, and rotors are from 74 Maverick (I also have on hand the manual mc from same), Hydroboost and mc from 99 Mustang GT and am planning to replace the stock rear drums of the 57 with parts from a Crown Victoria/Marque.

Seems like I have a box of problems, doesn't it?

Have you considered using the SCAREBIRD caliper adapters to be able to use KH-4 PISTON fixed calipers (and WILDWOOD now offers a direct replacement caliper if wanting to go flashy) on the stock spindle?

This will eliminate the GRANADA spindle setup that can cause alignment problems and bump-steer?

Why do you want rear disc?