74' Pedal Box Project

Rupunzell

Rupunzell

Bernice Loui
Time to re-do the pedal box for the 74.

OEM Fiat cylinders were sent to Karps Brake for sleeving in Stainless steel (304). At this point in time, I flat refuse to use the current afermarket replacement cylinders are they are not equal to Fiat OEM. This is the innards of the clutch master with new seals installed. The moving parts are coated with Dupont Krytox O-ring lube.

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Since this Fiat clutch master has the press in with spring clip and O-ring plastic inlet fitting.. that are not replaceable, the choice was made to thread the inlet port with a M24x1.5 tap and make a special fitting to allow using a 1/8" NPT threaded 37 degree -4 JIC fitting. The M24 to 1/8 NPT fitting was torqued to 50 ft/lb.

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Here is what the clutch master looks like when assembled:

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Side view:

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The fittings are installed with Loctite PTFE sealer on the inlet fitting. The M24 copper crush washer was re-used. This can be done by heating the copper washer to cherry red hot and allowing it to cool slowly. This anneals the copper allowing a proper seal. If this is not done or a new copper washer used, the fitting will not seal.


For the Brake master, Aluminum fitting were made in place of the OEM plastic. This allows 37 degree -4 JIC fittings to be used in the inlet hoses.
The inside of these fittings are cone shaped to help air bubbles move out out of the fitting. Air bubbles can sit inside of the fitting if there are flat areas within the fitting.

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Top view of the brake master cylinder. This is a Lancia Scorpion brake master with the single front outlet.

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Side View:

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Fiat OEM and part number in casting:

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The Wilwood brake pressure valve and mounting bracket parts:

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Bracket and Wilwood valve. The fittings are 37 degree JIC -3.

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Wilwood valve on bracket:

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Some time ago, this pedal box was bead blast cleaned, primer-ed with zinc phosphate and finished with silver paint. Another bearing bronze bushing for the pedals got made and this the beginnings of putting it together.

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View of the bearing bronze bushing, slot and new brake switch with push rods that are in prime condition. These push rods and pins on the pedals wear badly if neglected and causes pedal feel problems and lots of slop in the pedal system. Pins, push rods and ball joint ends were lubed with Swepco 101 Moly grease. New washers and stainless steel cotter pins installed. Main pedal bushing was lubed with Redline CV moly grease.

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View of the Wilwood brake valve and bracket on the clutch master side:

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These are the long bolts that mount the master cylinders. The long bolt is M8 x 195, shorter one is M8 x180. These are old and tired. As most know, I don't like re-using hardware if at all possible. Since AN-5 bolts of this length cannot be easily had, new 5/16 x 24 tip, 8.00" long, SAE grade 8 bolts were purchased then modified as the threads are too long. The threads are just long enough for the nut/washer. (about 2 to 2.5 thread diameters).

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Side view of the clutch master with WIlwood valve and bracket. One of the brake tubing has been made and installed, Note the caps on the fittings waiting for tubing. This is done to keep stuff that should not be in the brake system out. Everything is kept as clean as possible as the work moves forward:

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Brake master side with the old M8 bolts used hold the cylinders in place as the brake lines are made.

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Top view of the pedal box with brake lines installed and 1/4" Gate Adapta-flex EPDM hose with JIC 37 degree barbed fittings on the inlet side of the masters.

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Part two, filling the cylinders, purging air and testing.


Bernice
 
Speechless!!!

:clap::clap::clap::clap::clap::clap::clap:
:clap::clap::clap::clap::clap::clap::clap:
:clap::clap::clap::clap::clap::clap::clap:
:clap::clap::clap::clap::clap::clap::clap:
 
Several Questions...

...from the perspective of someone who would want to duplicate what you did with the cylinders for the ultimate in long-term reliability.


1. What did Karps charge for sleeving?


2. Did the cylinders come back with internal parts fitted or did you do that yourself?


3. If you fitted the internals yourself, what was the source and cost for the consummables (seals, etc).


Also, just curious about your decision process regarding using a double eared Oetiker clamp vs single eared on the barbies.
 
+1 on Dan's questions

I'd like to know, too.

Amazing attention to detail, nicely done!
 
Well done as always ...

...As we've come to expect from you Bernice. :clap:
I especially like the idea of adding the threaded fitting in place of the original plastic one. Great idea.

I rebuilt a clutch slave cylinder last year and found it's not so hard as long as you pay attention to detail.

Well done and thanks for sharing. Can't wait to see part 2.
 
...from the perspective of someone who would want to duplicate what you did with the cylinders for the ultimate in long-term reliability.


1. What did Karps charge for sleeving?

*Karps charges about $100 USD per cylinder to be sleeved in stainless steel. Yes, new aftermarket masters cost about $30 to $70 or so. It is possible they are all made by one supplier in Italy, Metelli SPA.
http://www.metelli.com/en/index.php

It is curious that new aftermarket cylinders can still be had for such a long time after they have gone out of production.

*Apple Hydro charges less for brass sleeving. Thinking about this, Stainless steel is more appealing in the long run as it addresses the corrosion issue when the fluid in the hydraulic system is neglected and allowed to corrode out the entire system. Brass can corrode, it is softer than stainless steel which can wear and according to both Karps & Apple Hydraulics cannot be honed in these cylinders.

*Given difficulty of servicing these cylinders, I'm gong to take every possible precaution and use the very best parts and greatest of care when putting this all back together as the pedal box assembly and it's cylinder are one of the more difficult things to do on an exxe.


2. Did the cylinders come back with internal parts fitted or did you do that yourself?

*Karps did the clean up and sleeving. They were taken apart here and inspected for the best possible core. Several were taken apart and the best cores were selected for sleeving. There is a small pile of cylinders here (both OEM Fiat and aftermarket) after this adventure.

3. If you fitted the internals yourself, what was the source and cost for the consummables (seals, etc).

*They were assembled here using the best piston parts from that pile of Fiat OEM cores. It is worth noting that the same brake master cylinder parts are used in other Fiats from this same vintage of similar size.

*The brake master pistons came out of a new old stock Fiat Strada brake master with new seals installed.

*The seals were sourced from a supplier in the EU, about $10 delivered.

It is worth noting that many Italian cars from this era used the same donut seals. This style of seal is used in Ferrari, Maserati and some Alfa Romeo and Lancia. It appears the Italians had their design ideas of how these cylinders are to be made. This kernel of info came from Jeff at Karps who has sleeved many, many cylinders over the years for all these Italian cars. Some of the cylinders they sleeve have no easy replacements due to their low production.

*The current aftermarket cylinders are made using the common cup seal with a completely different piston design which IMO, is inferior (cheapened and cost reduction-ed shorter service life and...) to the OEM Fiat. It is possible this is due to the price this market is willing to pay. If these aftermarket cylinders cost a few hundred USD and of very high quality, few if any would consider them for a car with low market value. It is possible the problem of low quality parts is due to the low market value of the exxe and what the market is willing to pay for replacement parts.

*Curious bit learned from this cylinder adventure, the inlet seals on the Fiat OEM master cylinders are made by ATE in Germany. The ATE logo is moulded into the seal. Got an image of this which I'll post later.

*Cylinders are normally assembled using brake fluid, brake assembly lube or brake assembly grease. The choice of Krytox assembly lube was made after trying a number of these other assembly lubricants, Krytox appears to work best. Except for cost which is $60 for a 60 gram tube.

*Not going to take any chances assembly on these cylinders. I want to know what was used, the exact condition of each part installed, how they were installed and what the tolerances are. This is why they were inspected and assembled here. It is worth noting that the clearance between cylinder and piston runs about 0.0015". If the clearance goes above 0.003" sealing within the cylinder & piston will have problems. Cup style seals are more forgiving in this regard, still this is why keeping the brake fluid clean, changed often and properly maintained with the proper fluid is imperative for proper brake and clutch operation.

*Karps brake can rebuild the entire cylinder with finishing if requested.

4. Also, just curious about your decision process regarding using a double eared Oetiker clamp vs single eared on the barbies.

*The clamps are on the feed side of the cylinder which normally have near zero pressure except when the system is pressurized for bleeding.

Double ear Oetiker clamps were what the hose shop had and the clamp pliers are the same for doing CV joint clamps. The alternative would have been to use no clamp or screw with band clamps often used in EFI system and OEM Fiat. These screw clamps work well until it is time to work on them.. Taking the apart can be not so easy.

The hose is 1/4" Gates Adapata Flex made of EPDM ( EPDM is one of the few rubber compounds compatible with brake fluid. If common Nitrile Rubber hose was used, there will be a fluid non-compatiability problem. Alternatives is Tygon tubing, Poly tubing or other compatible compounds. Silicon tubing tends to seep or absorb stuff making a less desirable choice.

Since the barb fitting have a 37 degree AN / JIC threaded fitting on the inlet side putting these fittings on the hose for good is not a service problem as they can be easily taken apart and re-assembled without problems.

This came about due to the absolute hassle and problems with push-on hose fittings with clamps. The are low cost, work fine except when it comes time to work on them, they can be awful.

And... if the hydraulic system is neglected in the exxe, it will drip fluid causing corrosion/rust between the pedal bearing sleeves and plastic bushing resulting in stuck pedals, sticking pedals and ...


Bernice
 
Problem with replacing the stock plastic inlet fitting, it must be made using a decent lathe with proper cutting tools. A speciality fitting like this is not off the shelf.

Rebuilding these cylinders is not difficult. Proper care and attention to keeping it all clean as possible with the proper parts and lube is all it takes.

There was a time when one can walk into the Fiat dealer parts department and order up a master cylinder. Minutes later, the parts guy would have the OEM Fiat part in your hand that same day. Those days are long gone for the exxe. This means taking the steps required to get proper OEM or better quality replacement parts.

I do believe if the market value or value to their owners were higher, more exxe owners would pay for higher quality parts. In the case of a Ferrari, Porsche or similar vehicle that is highly valued and perceived as special, their owners often have little issue with paying high cost for parts. Sadly not true for the exxe with few exceptions.



Bernice


bbrown said:
...As we've come to expect from you Bernice. :clap:
I especially like the idea of adding the threaded fitting in place of the original plastic one. Great idea.

I rebuilt a clutch slave cylinder last year and found it's not so hard as long as you pay attention to detail.

Well done and thanks for sharing. Can't wait to see part 2.
Click to expand...
 
pedal box

Bernice, I will ask what all the members want to know.
if a forum member sent you a pedal box with cylinders what would it cost to have you replicate it??
of course sans the prop. valve??
mikemo90*aol.com
 
No....

The amount of hours required to replicate this is immense. These images represents hours, days and weeks of work. It is more a hobby and passion and craft interest for me. When stuff like this is done for others, if something goes wrong.. bad stuff happens.

Same happened with the shifter that was designed for the Porsche 901 gear box, every Porsche-Phile that has seen it and tried it wants one. Same answer, no.



Bernice


mikemo90 said:
Bernice, I will ask what all the members want to know.
if a forum member sent you a pedal box with cylinders what would it cost to have you replicate it??
of course sans the prop. valve??
mikemo90*aol.com
Click to expand...
 
pedal box

I understand rupunsel's desire not to go forward with something like that.
no matter how good you make something, the install will always come back to the maker yelling that it isn't right!!!
how about a kit ...buyer beware.... done wrong it is ON the buyer, not the designer.
most of us don't need the high tech fittings that you have such as the prop valve, brass inlets in as much as we might want a super reliable brake/ clutch assembly.
if installed incorrectly, you shouldn't expect any boo-hoo's from the forum.
we are all big boys (girls) and should know what is needed to do the job.
I just had a spare pedal box and thought if I sent it..............
never mind
any thing you can replicate for us dopes out here .
mikemo90*aol.com
p.s. did you like the gas cap???
 
No one who does stuff like this is a "dope". In today's world of non-user serviceable vehicles, DIY is a really good thing specially for those who are trying to keep their exxe on the road. We are all on the road of learning, making mistakes and learning from what went wrong and trying again often allows reaching the goal.

Much of the info presented here is nothing more than an example of what can be done. Much of how and what was done is included for anyone who is interested to try much the same. This is never the only way as there are many other equally nice ways to achieve a similar to identical result.

I'll help where possible with info and such.


Yes, the gas cap arrived fine and looks as it should. The locking gas cap installed by the PO just did not make it.


Bernice


mikemo90 said:
I understand rupunsel's desire not to go forward with something like that.
no matter how good you make something, the install will always come back to the maker yelling that it isn't right!!!
how about a kit ...buyer beware.... done wrong it is ON the buyer, not the designer.
most of us don't need the high tech fittings that you have such as the prop valve, brass inlets in as much as we might want a super reliable brake/ clutch assembly.
if installed incorrectly, you shouldn't expect any boo-hoo's from the forum.
we are all big boys (girls) and should know what is needed to do the job.
I just had a spare pedal box and thought if I sent it..............
never mind
any thing you can replicate for us dopes out here .
mikemo90*aol.com
p.s. did you like the gas cap???
Click to expand...
 
Yes, to me it looks like it would be:

1. Gather up a set of cylinders
2. Send out to be sleeved in stainless by a reputable shop
3. Hardest part, acquiring top-quality replacement innards
4. Assemble in a clean environment and meticulous fashion
 
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