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Discussion Starter · #1 ·
Hi everybody,

As you can see picture 1 (taken on the car as I found them, noted Front Left and Front Right), my front brakes have been reassembled in a distant past by somebody probably rather stupid who turned them by 90 degrees.
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Consequently, the 2 pin for brake-shoes adjustment cam on the back side of the back-plate (picture 2) were hitting the lower and the upper wishbones, and so limitating dramatically the steering radius.
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This stupid man, just noticing that the brake pipe bracket was not in the right spot, simply cutted it and rewelded it...
And icing on the cake, the right and left hand hubs were inverted, the knock of nut of one of my front Borrani wheel decided to take some vacation while I was driving, so did the wheel...
But this is not the object of my request in this thread.

I do not understand the logic of functioning of these front drum brakes as they are fitted on the car.
The eccentric (cam) (picture 3)
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is there to catch up the free play between the brake shoe and the drum, according to the wear of the shoe lining. When one acts on the eccentric, the brake shoe is radially pushed towards the drum, thus decreasing the clearance between the brake lining and the drum (picture 1 : A = shoe moving axis by eccentric adjustment).
The best setting is when there is minimum clearance between brake shoe lining and drum, but with no contact otherwise permanent breaking.
The eccentric pushes the shoe, but does not pull it the other way (picture 4 : no element acts for the return motion of the brake shoe against the eccentric).
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Then the rotation of the drum - as designed by Alfa - subsequently tends to move away the shoe from the eccentric (shouldn’t the eccentric retain the braking shoe?). In this regard, the shoe tends to act as a self blocking device against the drum.
What is therefore the purpose of the eccentric in this assembling design?
IMO, the opposite rotation would be much more consistent for what the braking system is aimed at. This would be achievable by inverting the right and the left hand back plates. But in this case, the originally welded brake pipe bracket location would be found at the front of the wheel axis, what would definitely be a wrong layout.

In the meantime, I cannot find any evidence on the Alfa DVD providing hard statement about this subject (neither in texts nor in pictures).

In French, we talk about “swallowing” design (or “wedge trapping” layout, by opposition to “wedge escaping” layout), when the brake shoe cylinder pushes in the same direction than the drum rotation.
Both design were used in drum brakes, the “swallowing” providing a more aggressive braking.
But in this present case, this layout seems incompatible to me according to the way the brake shoes adjustment cam works.

Something must be wrong on my car, VIN 1020402892 manufactured on dec. 9 1960 and
assembled at Touring on may 1961.

Many thanks in advance for helping me
 

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Brakes are partly self adjusting version but mixed up.

I know what you mean when you say the wire wheels came off, and why. That is because the threads to tighten the knock offs were incorrect -- the right handed thread is supposed to be on the left and vice versa. Otherwise the wind resistance keeps pushing and pushing and finally unscrews the knock-offs. If put on correctly that is not a problem. It is not a right handed Knock off that is on the right side -- just opposite. I once incorrectly installed the "spider" for the rear wheels and experienced losing a wheel.

However, because your wheel came off on the front the stub axles were somehow on the car upside down. The arms on the front stub axles must always line up with the steering box and drag links so I can't visualize how it could have happened otherwise. I suspect that the front suspension was taken apart and somehow on being put back together the small A frames for the top ended up where the long A frames should have been on the bottom and vice versa. Go check and verify that the zerk grease fitting is on the top where it should be. Take a look at that FIRST.

But that doesn't explain why someone was so frustrated as to redo the holes in the backing plates. The mechanic was certainly sure which brake backing plate came off which side. He was just trying to get something to work. He must have succeeded. If you had brakes I must at least commend him.

But I believe there is something very very wrong. I like self adjusting brakes, and know the shoes are correct for the very newest two liters (don't go by VIN number because they skipped around in sequence) which have them. But it looks like the backing plates and also the cylinders are actually for one of the two earlier versions of brakes for two liters. I've had a dozen so I have seen all of the three kinds. But the shoes are NOT correct for the backing plates. On self adjusting set ups there is no eccentric on the sides. Instead, the front cylinders have an eccentric movable turning pin on one of the two bolts holding it on . That eccentric can be turned and adjust the end of the shoe opposite from the piston which pushes out when the brakes are applied. The pictures show there are adjusters taken from the earlier brake style and somehow added in strange locations. They don't work. It's worse than apples and oranges.

So, my friend, you must either get some of the self adjusting cylinders and backing plates to go with your self adjusting shoes, or go back to the old shoes (and probably un-cobbled and cut up backing plates with adjusters which are not self adjusting.

But check where the zerk fittings are on the front axles first. Might as well avoid losing another wheel. Check which way the rear wheels knock offs tighten too. Since no two liter came from the factory right had RHD drive the right side (i.e. passenger side) needs the left had thread so the wind resistance doesn't unscrew it.

Then go look what you have in the line of front cylinders, backing plates and shoes to get full sets. Remember that for the self adjusting ones (the ones with the huge six side nut like appearance on the side) cylinders are required that have the mounting bolt eccentric to provide an adjustment for the opposite end of the shoe not moved by the piston. They are Girling too, but an advanced version that came out after the parts book was published. So they are not shown in the regular material and you learn about it only by experience. However, I am not correctly logged on or I would be sending you a page form the AFRA catalog which shows both types of front cylinders. If you want a copy, ask me. I'll log in right. Your shoes look good, but you need the right cylinders and backing plate for them. One way or the other. You can't mix and match. Check to see what parts you do have. I think you could put your backing plates back together right for one or the other. If you need parts I might have enough except for cylinders. They aren't that expensive, however, from AFRA. Everything is relative. By the way, I don't understand why your turning radius was compromised. I'd love to get under your car and look.

I also seem to recall the brake line coming first to the top cylinder and then running from it to to the bottom one with the adjuster screw. Once you get the right combination of cylinders, shoes and backing plate you can change that. If you really get desperate I probably could go down into the garage and take pictures. I believe I have sets of all three kinds.


i
 

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Otherwise the wind resistance keeps pushing and pushing and finally unscrews the knock-offs.
I can't comment on the other issues, but I don't think it's "wind resistance" that makes wheel nuts come loose (just imagine: the wind forces would cancel each other out on the ears on opposite sides of the spinner of a wire wheel).

Most likely, the reason why wheel nuts come loose (no matter whether center lock for wire wheels or multiple lugs for disc wheels) is friction that happens on the mating surfaces as a result of lugs and nuts and holes of the wheels not being perfectly shaped and/or aligned, which leads to some degree of eccentricity under weight bearing conditions. The forces applied use the same principle as swinging on a hoola hoop ring -- depending on the direction of rotation and direction of the threading, the hoola hoop action would either tighten or loosen the nuts.

Add to that the forces of acceleration, deceleration and cornering, and the effects of camber and toe-in to stabilize directional behavior, and the forces on a wheel nut become quite complex -- but, as stated above, I believe wind resistance has nothing to do with it.
 

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Some Girling info on Alfa 2000 brakes:
 

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The above extract from the manual addresses the early manually-adjusted brakes only. I've never found a thorough discussion of the later automatically-adjusted brakes anywhere, and although I have a complete set of auto-adjusting brakes in my spares, I prefer the manual. Less room is taken in my diminishing memory banks.

If, as Jay notes, the original poster has a mix and match of components from the manual and auto brakes, the only smart solution is to come up with a complete matching set of one or the other. For some reason, I'm recalling that the manual brakes have the cylinders at the top and bottom as shown, whereas the auto have them positioned fore and aft.

I vaguely recall a friend with a Spitfire who accidentally swapped the hubs on the front such that the left hand thread were on the right side and the right hand threads on the left side. I think he made it about 100 feet from my house before both front wheels fell off into the street. Jay's advice is to the contrary, but I have no experience with Alfa knock-offs, so can't debate it one way or the other. I'm surprised the method would be opposite that of the Spitfire, though.
 

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One thing that I can add is that my "snail shell" adjusters have little notches along their length. The 'auto adjusting' snail shell adjusters are smooth.

Most likely, the reason why wheel nuts come loose (no matter whether center lock for wire wheels or multiple lugs for disc wheels) is friction that happens on the mating surfaces as a result of lugs and nuts and holes of the wheels not being perfectly shaped and/or aligned, which leads to some degree of eccentricity under weight bearing conditions.

I believe Ruedi is right about the knock-off nuts, maybe it is easier to remember 'which way the knock off nuts go' based on the direction of wind resistance. I had heard horror stories from others regarding wire wheels coming off and was bound and determined not to let that happen to me.

The first time I installed the splined hubs, I used Loctite red and put the hubs on "the wrong sides" of the car! Later I realized, after heating the lug nuts with a torch to melt the Loctite, that the only thing they held on was the brake drum. Once the large knock off nut was installed and torqued to 380 ft-lbs the 'lug nuts' became obsolete. I had to borrow a hub puller from a buddy with a 275 GTB (his tool kit was probably worth as much as my car) so I could swap the hubs.

I met a guy with a Lotus at a local 'Cruise In' car show. I noticed that the knock-off nuts for his alloy disc wheels were on "wrong"! Well, they were opposite my knock-off nuts. We both did a lot of research and studying photographs on the internet trying to convince each other to change their hubs around. It turns out that his Lotus, with disc wheels (non-spoked) were on the proper side for his car and so were my Borrani wire wheels on opposite his. Each were on the correct side for our set up! In other words; What is correct for 'disc' wheels is opposite that which is correct for wire spoke wheels. Had we listened to each other, our wheels would likely have fallen off.

Mark
 

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In other words; What is correct for 'disc' wheels is opposite that which is correct for wire spoke wheels.
The reason why this is the case stems from the fact that the car "stands" on the disc wheel (i.e. weight bearing is between axle and ground) but "hangs" off the spokes of the wire wheel (i.e. weight bearing forces act from axle to top of rim, then through the rim down to ground), which changes the direction of the friction (i.e whether hoola hoop action will be applied clockwise of counter-clockwise).
 

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At least my wire wheels don't come off anymore

Man on man! I am reminded about the man born blind that Jesus cured. The Sanhedrin brought him in to question him. He had no explanation except that he could see. I can only say that my wheels no longer get loose and fall off.

It can't be all that quaking and shaking and way of hanging that makes all the difference. I was very aware that on the Alfa 102/2000 spider one uses right hand lug nuts on the right side and left hand lug nuts on the left when putting on the wheels. In fact, because I knew that I was able to change the tire on the left side of the first such car I ever saw. I realized the lug nuts on the left side had left hand threads. Because of that I was allowed to drive that car and became bitten by the Alfa snake. I am totally aware..

And when I got my wire wheels I just assumed the knock off also just had to go right hand thread on the right side and left hand on the left. I took great care to make things that way. And the wire wheels would get loose, actually fall off. I recall driving to Malcolm Harris's fine home in Seattle, turning into his driveway and having the right front wheel knockoff falling into his yard (thank goodness it was not bounced along on the concrete). My son driving my car had the same thing happen on the streets of Vancouver, BC when I let him take it for a spring break in college. There was a disturbing history, and it needed a solution.

So I switched, being very careful to put the threads for the knockoffs just opposite -- the left handed threads on the right side and the left handed threads on the left. I used no locktite, no super glue, no fancy stickup. I just hammered the knockoff up tight again. And guess what! I have never had my wheels get loose since, and remember I drove this car as my daily driver from 1965 (although I got the wire wheels in 1975 or so) until 1990. And in the old Latin logic the phrase: "Esse ad posse valet illatio" -- One can validly argue from the fact that something actually works that it can work.-- applies.

My theory is that when the knock offs are spinning both ears incur air resistance. Remember the air can lift huge airplanes. Don't discount air resistance or force of the air. And, incidentally, perhaps that is why some of those English knock offs are shaped in such a way is to avoid wind resistance. I do not know how those turn to get tightened. Maybe they can get away with right hand threads on the right side if the knock off is shaped in such a way that the wind resistance is not a factor. I am not an engineer. I am not a scientist. I am merely a practical man. Because I go forward most of the time I prefer having the air resistance tend to cause a force to make the knock offs get tighter. But if one tries to analyze all those other explanations of how Alfa knock offs (i.e. Barranni style with ears sticking out) get loose, one also has to explain how merely reversing the direction of tightening in relation to the wind resistance pushing on the ears of the knock offs makes such a difference. All those other events given as explanations were not changed. I am a simple man. My knock offs no longer come loose. They used to. As the say - QED: "Quod erat demonstrandum" (more Latin), even if the proof to me is something more than a mental construct in this case. Frankly, you are NOT going to be able to convince me to change back. And, once again, I advise that poor fellow in France with cobbled up brakes to check which way the threads go on his knock offs. And, of course, to get his brakes one way or the other. I suspect that although he might have some extra holes left over in his baking plates he could solve everything by getting the right style front brake cylinders from AFRA:
AFRA phone 011 39 02 328 6111
Settimo Milanese (MI)
Via Carducci 36-38
Italia Claudio Giorgetti (Speaks English)
[email protected]
 

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Jay, that was my logic exactly! Perhaps great minds think alike...unfortunately we were both wrong!
I was very aware that on the Alfa 102/2000 spider one uses right hand lug nuts on the right side and left hand lug nuts on the left when putting on the wheels...
And when I got my wire wheels I just assumed the knock off also just had to go right hand thread on the right side and left hand on the left. "Esse ad posse valet illatio" -- One can validly argue from the fact that something actually works that it can work.-- applies.

I am merely a practical man...I am a simple man.
Jay, just for you:
simple man lynard skynard - Bing
Mark
 

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Discussion Starter · #10 ·
For Jay, here is why my turning radius was compromised :
picture 1 : showing front right hand end,
point C1 (Contact 1) on upper rear wishbone is contact with upper brake-shoes adjustment cam pin limitating right hand turn circle,
and C2 (Contact 2) on lower front wishbone is contact with lower brake-shoes adjustment cam pin limitating left hand turn circle.

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Picture 3 : (taken by the front of the backplate) showing C1

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Picture 4 : (taken by the rear of the backplate) showing C2

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Concerning the reason why wheel nuts come loose, I totally agree with Ruedi and I love the way he describe this phenomenon with the “hoola hoop action”, this is by far the main effect.
With center wheel nut, the left hand wheels must have a right hand thread nut and vice-versa for the other side.
At least with Borrani wire wheels and that’s what they told me recently on the phone.

In response to Jay :

<<However, because your wheel came off on the front the stub axles were somehow on the car upside down. The arms on the front stub axles must always line up with the steering box and drag links so I can't visualize how it could have happened otherwise.>>

The front stub axles are correct on my car.
I just had to invert the hubs, from the front right hand side to the left (picture 2).

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Same for the rear.

Here is the reason why I do not want that to happen again :

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Jay, sorry but I don’t understand what you mean by :

<<I suspect that the front suspension was taken apart and somehow on being put back together the small A frames for the top ended up where the long A frames should have been on the bottom and vice versa. Go check and verify that the zerk grease fitting is on the top where it should be. Take a look at that FIRST.>>

Perhaps do you have a answer on the picture 1 ?

I do not see anything wrong on picture 1 unless perhaps the fact that the link rod for the stabiliser rod seems to me tilted instead of more or less parallel to the fulcrum for stub axle (or shock absorber).
Could it be that my stabiliser rod is too long (the part which is bend at each end), coming from another car model ?

Regards,
Roland
 

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I'll try to find documentation, but I believe the auto-adjust brake version positions the two cylinders fore and aft rather than high and low.
 

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I took at look at my self-adjusting brake parts, and took pictures. Unfortunately, my PC has forgotten how to upload pics from my IPhone. I'm working on that.

The backing plates for the auto-adjusting brake system definitely position the cylinders fore and aft. You can see how this will immediately resolve the interference problems you have. However, as Jay noted, you've got the wrong backing plates, and who knows what else is incorrect.

If you plan to have a safe and reliable car, you'll need to get all the right parts in the same place at the same time.
 

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Here's a couple of pics from the front suspension manual.
 

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I suspect a mechanic may have been confused by the differences between depictions in the parts catalog (showing brake shoes front and back, same as in Girling description posted above) vs. the shop manual (showing brake shoes top and bottom).

The parts catalog indicates that the piping on the front backing plates was changed during production (but there seems to have been no change to the backing plates). Girling info copied further below indicates that the front brake slave cylinders and the return spring for the brake shoes were also changed. But no other changes. I'm not aware of any Alfa Romeo TSB advising of making changes to the brake setup.

So, as indicated in post #1 above, the problem indeed seems to stem from the backing plates having been rotated 90 degrees (brake shoes back to vertical) by a mechanic. If so, rotating them to horizontal brake shoe position (possibly with L/R reversal) should not be a big problem with new piping on the backing plates.

The parts catalog and shop manual pages below are from the CarDisc DVD.

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The pictures don't really convince me one way or another whether the subject car has early backing plates or late. It could well be that it has the early non-adjusting plate, which should be mounted as shown, but equipped with the wrong shoes and cylinders.

If you need it, I can pull out my auto-adjust backing plate and take pictures.
 

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Also....

The Alfa parts book essentially makes no mention of the later auto-adjusting system. We should not assume that showing only one part number for the backing plate means there is only one part. It's as though Alfa was on the verge of ditching the 2000 in favor of the 2600, so why bother with updating the records to cover the auto-adjusting system?

The Girling catalog at leasts acknowledges that there were two different systems, but as they note, the backing plate, shoes, etc were to be supplied by Alfa.

I'd say this situation requires a whole do-over.
 

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The Alfa parts book essentially makes no mention of the later auto-adjusting system.
There were two amendments to the parts catalog -- the second one contains the 102 Sprint body parts and is rarely ever seen (and not included on the CarDisc DVD I checked). I sold the parts catalog I had scanned but the hard disk with the scans (and its backup) crashed. I can't remember I there was an amendment note that mentioned the adjusters. Does anybody have a full parts catalog with amendments 1 + 2?
 

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Don, off subject but did you not sell your Montreal last year?

Dennis
Dennis,

Not yet. I decided to do "the full Monty" on the engine bay first. This has led to a complete overhaul of the engine, and detailing of the bay and underbody. Progress is being made.
 
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