LarryC
Curator of #10105275
Whoa! That's a useful diagram there. Went right into my master cylinder folder.
Fixed: Brake Master Change Nightmare, thanks to RX1900 (See pg4)
- Thread starter BrianM
- Start date
Rupunzell
Bernice Loui
Yes, any quality anti-seize works long as not too much is applied and only applied to the threaded areas, Keep the anti-seize off the ends of the brake tubing's open ends to prevent and minimize any anti-seize from entering the brake fluid system.
Bernice
Mark_Toro
True Classic
I can't wait to dig in to this on my X. (really, this is a rite of passage). The pictures are helpful.
I'm not a real engineer (designed lawnmowers for 20 years until mgmt called), but I would never design a bolted joint to hold a load in shear. A joint like this should be designed that the compressive load (bolt tension) prevents any possible motion of the joint. If the bolt goes into shear, then the joint has already failed (you have relative motion).
The comments about using junk material are still valid, because you won't be able to attain reliable, adequate clamp load with poor material.
Of course who knows what 1970's Italian engineers were thinking as they designed this particular joint (I've made errors too)
I'm not a real engineer (designed lawnmowers for 20 years until mgmt called), but I would never design a bolted joint to hold a load in shear. A joint like this should be designed that the compressive load (bolt tension) prevents any possible motion of the joint. If the bolt goes into shear, then the joint has already failed (you have relative motion).
The comments about using junk material are still valid, because you won't be able to attain reliable, adequate clamp load with poor material.
Of course who knows what 1970's Italian engineers were thinking as they designed this particular joint (I've made errors too)
Steve Thomas
True Classic
Yes but no but. Yes, a joint can be designed to operate on the basis of friction developed by clamp load. It is far simpler to assume that initial loading [in a case like these bolts that hold the masters and those union blocks onto the pedal box] will take up any slop/tolerance and that subsequent load is carried in shear. Easier to design and very much safer with respect to joints that will be repeatedly disassembled/reassembled by variable quality workforce. The primary load is unidirectional so no need to worry about parts shunting back and forth. The torque on these bolts is to ensure they don't come undone and to securely gather up a bunch of parts. Yes, the clamping load will give a friction component as well but very dependent on the condition of all those interfaces.I can't wait to dig in to this on my X. (really, this is a rite of passage). The pictures are helpful.
I'm not a real engineer (designed lawnmowers for 20 years until mgmt called), but I would never design a bolted joint to hold a load in shear. A joint like this should be designed that the compressive load (bolt tension) prevents any possible motion of the joint. If the bolt goes into shear, then the joint has already failed (you have relative motion).
The comments about using junk material are still valid, because you won't be able to attain reliable, adequate clamp load with poor material.
Of course who knows what 1970's Italian engineers were thinking as they designed this particular joint (I've made errors too)
LarryC
Curator of #10105275
My thoughts immediately turned to the axle CV joint attachments....I can't wait to dig in to this on my X. (really, this is a rite of passage). The pictures are helpful.
I'm not a real engineer (designed lawnmowers for 20 years until mgmt called), but I would never design a bolted joint to hold a load in shear. A joint like this should be designed that the compressive load (bolt tension) prevents any possible motion of the joint. If the bolt goes into shear, then the joint has already failed (you have relative motion).
The comments about using junk material are still valid, because you won't be able to attain reliable, adequate clamp load with poor material.
Of course who knows what 1970's Italian engineers were thinking as they designed this particular joint (I've made errors too)
Steve Thomas
True Classic
One of the many, many reasons why tripods are better.
Dan Sarandrea (Phila)
Waitin' On Parts...
Yes, it's a mystery how six measly 10.9 capscrews can stand up to all that engine torque!
SuperTopo
True Classic
I can't wait to dig in to this on my X. (really, this is a rite of passage). The pictures are helpful.
I'm not a real engineer (designed lawnmowers for 20 years until mgmt called), but I would never design a bolted joint to hold a load in shear. A joint like this should be designed that the compressive load (bolt tension) prevents any possible motion of the joint. If the bolt goes into shear, then the joint has already failed (you have relative motion).
The comments about using junk material are still valid, because you won't be able to attain reliable, adequate clamp load with poor material.
Of course who knows what 1970's Italian engineers were thinking as they designed this particular joint (I've made errors too)
This is bang on. A slipped joint is a failed joint.
Steve Thomas
True Classic
Terminology problem. Not worth bogging this thread down anymore than we have
Clatter
True Classic
Taking my pedal assembly apart today,
This is how these through-bolts were done.
Far as i can tell this is factory?
That’s a spacer…
All this talk about clamp loading and shear..
Pretty sure they didn’t think about these type of things at Fiat back then.
They built it like it seemed right, and if it worked, great.
If not, maybe they would try something else.
This is how these through-bolts were done.
Far as i can tell this is factory?
That’s a spacer…
All this talk about clamp loading and shear..
Pretty sure they didn’t think about these type of things at Fiat back then.
They built it like it seemed right, and if it worked, great.
If not, maybe they would try something else.
Steve Thomas
True Classic
FIAT in the late 60s [when X was designed] was a pretty hard core engineering team.
Tom Ginefra
True Classic
Outstanding choice of beverage!
Steve Thomas
True Classic
I don't think so. I suspect the double union block [ref post #11] that should under the head end of that bolt is missing? Or the bolt is just not the correct bolt. I really do not see that as ex-factory!
Clatter
True Classic
Gotta keep lubricated…
A friend was doing the floors on a Miura.
It seemed mostly handmade.
Interesting welding and hole punch work.
Accuracy wasn’t impressive.
Definitely fabricated.
Not that a Miura isn’t a fabulous car,
But the build quality of the shell itself was pretty rough.
I’m finding out that the X is similar in certain ways, even though, unlike the Miura, it was produced in volume in a big factory.
They get the big parts and the design done well,
But when it comes to finishing out details they don’t sweat the small stuff.
Like that spacer holding the masters.
Sorry to babble,
But I’ve worked on a lot of German and USA stuff, and this design philosophy is kinda tripping me out.
It really resembles home-made hot rod or race car fab.
When they got to say fasteners or serviceability, detail/finish stuff, seems like they were over it and moving on to something else already.
A friend was doing the floors on a Miura.
It seemed mostly handmade.
Interesting welding and hole punch work.
Accuracy wasn’t impressive.
Definitely fabricated.
Not that a Miura isn’t a fabulous car,
But the build quality of the shell itself was pretty rough.
I’m finding out that the X is similar in certain ways, even though, unlike the Miura, it was produced in volume in a big factory.
They get the big parts and the design done well,
But when it comes to finishing out details they don’t sweat the small stuff.
Like that spacer holding the masters.
Sorry to babble,
But I’ve worked on a lot of German and USA stuff, and this design philosophy is kinda tripping me out.
It really resembles home-made hot rod or race car fab.
When they got to say fasteners or serviceability, detail/finish stuff, seems like they were over it and moving on to something else already.
fiatfactory
Steve Cecchele
nope, because the thru bolt is fed in from the other direction from the factory, in from the left...,. that lets you (in a LHD car) retract the bolt and remove the BMC without dropping the pedal box. (or possibly even retract it completely) On a RHD car it's also fed in from the left - which presents a problem - as the thru bolt hits the heater assembly and you definitely can't extract the thru bolt without dropping the pedal box. And that spacer is not in the factory fitted position, and you're also missing the clutch assist spring and associated bracket ....
SteveC
Steve Thomas
True Classic
Not really. 160k over 15 years comes out about 10k per annum. Even allowing for low rate in the last years and say 15k per annum in the earlier years. That is low volume and marginally economic. Not economic for FIAT hence body outsourced to a small manufacturer [Bertone] and the general use of parts bin items. For perspective, somewhere around 3 million 128.
rx1900
1981 X1/9
NO !!! I'm pretty sure your pedal box has been worked on before and someone assembled it incorrectly. That spacer you see does NOT go there. Instead...it should be on the other end of that bolt....between the brake master and the double junction block. See the pic below with the pencil pointing to that spacer. These are from my '81 X1/9 - same year as yours.....
Sorry.....I dont agree. I do think...that from the factory....on LHD X1/9s.....the bolts were fed in from the RIGHT side ( that is from the middle of the car ) . As in the above pics. It would seem the intention was to allow you to easily change the clutch master ! As further proof....below are pics from my factory Fiat North America official workshop manual. You can clearly see the nut end of the bolts on the clutch master side. I have no idea how the bolts were fitted on your Aussie RHD cars.......
Rupunzell
Bernice Loui
Gotta keep lubricated…
A friend was doing the floors on a Miura.
It seemed mostly handmade.
Interesting welding and hole punch work.
Accuracy wasn’t impressive.
Definitely fabricated.
Not that a Miura isn’t a fabulous car,
But the build quality of the shell itself was pretty rough.
I’m finding out that the X is similar in certain ways, even though, unlike the Miura, it was produced in volume in a big factory.
They get the big parts and the design done well,
But when it comes to finishing out details they don’t sweat the small stuff.
Like that spacer holding the masters.
Sorry to babble,
But I’ve worked on a lot of German and USA stuff, and this design philosophy is kinda tripping me out.
It really resembles home-made hot rod or race car fab.
When they got to say fasteners or serviceability, detail/finish stuff, seems like they were over it and moving on to something else already.
Yep, the miura is a hand built car in much the same way as many other "coach built" low volume cars. This includes "German" status cars like the Mercedes 300SL, early Porsche 911's, countless early Ferrari, Maserati, Morgan and many more. They are equally poor with their accuracy of fab as a result of being hand built in small numbers. You'll discover and find the same on many early aluminum airframe aircraft as their panels were hand beaten/shaped identical to coach built car bodies.
About zero wrong with this, consider appreciating the folks that pounded, wheeled and more to shape panels to fit a specific body.
While the exxe was built in large_ish numbers it remains a coach built car with a lot of hand built aspects. Keep in mind all that was learned by the group that designed/built the Lambo miura applied what they learned into the exxe...
Take the time to read this article in Hemmings, specially the side bar about the exxe..
What you're dealing with is a low production semi-hand built car with it's design rooted in the Lambo miura and Lancia Stratos... with parts of this design transplanted to the Lancia MonteCarlo.. It's all very incestuous within the same small group of Italian designers..
Bernice
Last edited:
JKIDD
Auto Addict
Agreed. I was able to replace my CMC in the car, but there was no way to do the BMC without removing the box.
Ics19
belle macchine!
The RHD cars have the clutch spring on the left side and uses a bracket that the LHD cars don't have/need, see pic in previous thread:
Pedal box removal and rebuilding
So I bought my 85 X1/9 and when it was delivered I looked at the carpet where the Master brake cylinder had leaked. I decided my first job would be replacing that Master brake cylinder (MBC). So I started to read and learn then execute. Below is my experience and how I did it along with gotchas...
xwebforums.com