Brake Box rebuild have some questions

KBabcock

True Classic
I'm just finishing rebuilding the brake box on my car. Stripped it down to pieces, derusted and cleaned all parts, repainted, reassembled and repacked everything in marine grade silicone grease. Now I have 3 questions which I have not been able to find.

1) Is there any exploded images of the brake box. I can not find any in the shop manual or elsewhere. The box was disassembled before and I want to make sure it was put together right with all parts. Mainly concerned about the two long bolts and what washer should be used in what order. I only have what I disassembled to go by.

2) How should the brake light switch be adjusted properly, it obviously set the travel of the brake pedal so setting it right would seem to be important.

3) Same question about the clutch pedal and setting its travel, I see it says 6.5" in the manuel but want to hear any other insight that might be out their from those who have done it.
 
There is an excellent photo rebuild by Bernice (Rapunzell) you can reference.

As for the setting the up stops you want both pedals even. Adjust the brake light switch so when the pedal is on the up stop the switch is closed and when moved off the stop it is on, a continuity tester will be your friend to do this.


There really are not that many parts. All years are identical with the exception that the late ones used the larger diameter supply nipples to the brake master cylinders.

Some prefer to omit the OE bolts and go to all thread so the clutch master can be removed without removing the entire box.
 
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Hi. Perhaps this may help. I just removed the pedal box from my '81 USA X1/9. You dont say what year your's is - always good to say that - but I think all years were pretty similar. To my knowledge...the pedal box in my X had never been removed before.

In the pics below....some nuts and lines have been loosened....but not yet removed.

You will also note my initial efforts to attempt to easily remove that heavy clutch spring. I yanked the clutch pedal towards the driver...so the spring becomes stretched a bit...and jammed some washers between the coils as you can see. You could also use pennies !!!. Now...when the pedal is yanked to its other position ( towards the floor )...the spring is now loose enough to be easily removed and set aside. When re-installing the spring...just reverse the procedure and pull out the washers. Easy-peasy....

As for the pedal adjustments.....I could be wrong here and someone please correct me if I am...but I was always taught that they should be adjusted so that the pushrods end up with just a hair of free play where they engage the end of the cylinders. There is a large 12mm bolt on the clutch side to adjust this. And it seems the brake light switch sets this on the brake side......

It is perhaps worth noting that on my X...they are not all the same...that the clutch reservoir line is 6mm ID, and the brake reservoir lines are 8mm ID. I would highly recommend that change those lines as well.

Hope the pics below can answer some of your questions. If you have any specific question...just ask. Doug

x19 pedal box 1.jpg
x19 pedal box 2.jpg
x19 depal box 3.jpg
x19 pedal box 4.jpg
x19 pedal box 5.jpg
x19 pedal box 6.jpg
x19 pedal box 7.jpg
x19 pedal box 8.jpg
 
Thanks for the replay's and pictures all very helpful. There is enough here that I feel comfortable with the reassembly.

RX1900, thanks for the tips on adjustment advise, I was thinking along the same lines. By the way my car is a 1985, the previous owner did a major restoration 10 years ago, professionally rebuilt trans and engine then had to store the car away after being 95% of the way there. Health issue prevented him from ever getting back to the car, he never got it started due to fuel injection issues. I am now the owner and finishing things up. reservou lines were replace 10 years and look good.

I took a different approach to the clutch spring which worked well for me both installing and removing it. Took a screw type carabiner and clipped onto the spring end, double lined a nylon rope to the carabiner then wrapped it around a wooden dole rod (be sure to wrap the rope over it's self around the rod to eliminate slippage) Two feet on the box and pull. Worked like a charm.

1626112316866.png

1626112334541.png
 
Yeah....you will be fine. It could indeed be possible to re-assemble with one of those distribution blocks upside-down or backwards. Just look at the pics of mine as I'm 99% sure that is correct. And do note there is a spacer between the brake master cyl and the double spacer block. I will look again tonight...but I dont think there are any washers between the master cylinders and the big metal channel piece....Just a flat washer under the bolt head...and a lock washer under the nut. EDIT.... there are FLAT washers under the nuts - not lock washers. And note those 8mm bolts get inserted from the brake side.

Just one big note of caution....be VERY careful when screwing in the jumper lines and the brake lines into those distribution blocks. As for some reason...perhaps because they are aluminum or brass...it is VERY easy to cross-thread them ( right Todd ? ). I found it best to run a bolt ( m10 x 1.25 ) into all the holes first..and be sure the bolt threads in easily by hand only..to ensure the threads are good. It seems that the brake lines...with the nut on them....if not perfectly 90 degrees to entry.....can tend to lead to cross-threading.....If the line nut does not thread in easily by hand...do NOT attempt to force it with a wrench !!!!

And hey....one question for you...I have not yet dismantled that big pivot bolt. i'm a little concerned about that wound spring on the brake pedal. Is it going to go boing and unwind itself several revolutions on me when released ?? Or no worries there ??
 
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Yeah....you will be fine. It could indeed be possible to re-assemble with one of those distribution blocks upside-down or backwards. Just look at the pics of mine as I'm 99% sure that is correct. And do note there is a spacer between the brake master cyl and the double spacer block. I will look again tonight...but I dont think there are any washers between the master cylinders and the big metal channel piece....Just a flat washer under the bolt head...and a lock washer under the nut. And note those 8mm bolts get inserted from the brake side.

Just one big note of caution....be VERY careful when screwing in the jumper lines and the brake lines into those distribution blocks. As for some reason...perhaps because they are aluminum or brass...it is VERY easy to cross-thread them ( right Todd ? ). I found it best to run a bolt ( m10 x 1.25 ) into all the holes first..and be sure the bolt threads in easily by hand only..to ensure the threads are good. It seems that the brake lines...with the nut on them....if not perfectly 90 degrees to entry.....can tend to lead to cross-threading.....If the line nut does not thread in easily by hand...do NOT attempt to force it with a wrench !!!!

And hey....one question for you...I have not yet dismantled that big pivot bolt. i'm a little concerned about that wound spring on the brake pedal. Is it going to go boing and unwind itself several revolutions on me when released ?? Or no worries there ??
Thanks for the heads up and I appreciate any pictures you can send that show washer and spacer placement, I don't have any lock washers on my box. These are the things I was looking for. It's crazy FIAT did not do an exploded diagram of this but such is life.

Ya, I read all about the blocks being easily cross threaded, plan to finger tighten for a bit. Also plan to use just a dab of anti seize on them.

The spring on the break return has very little tension, no 360 winding to it. Mine was a little rusted and would not even move the pedal all the way back to position. Cleaned it up and greased it well, now works as expect but again very safe to deal with. The biggest pain was removing the plastic shaft from the brake pedal rides on, mine was really rusted on (it's a tight tolerance and the pedal rusting inside cause a pressure fit). I was told do not hit it with a hammer and to use a press but did not have one so users a metal bar, various cut length of pipe and two c clamps to force it out (see below). You definitely want to clean this up get rid of the rust and grease it up well. If not it will pivot the plastic shaft rather than pivoting on it, this in turn will cause the shaft to get cut into by the brake box walls, eventually failing.
1626126711241.png
1626126739671.png


Also when you get it apart you can de-rust it to the bear metal by dumping it in a vat of Apple Cider Vinegar, it will eat every trace of rust off it in 2 days. When done wash it in a solution of water and baking soda to neutralize the acid and prevent ant rusting when removed from the vat. Blow it dry with compressed air which will also blow off any loose or loosened paint. This works really well on other parts as well, I've made completely rust covered screw look new. Just be aware that this process will eat away any galvanization protection on a part so be careful with what you treat.
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Thanks for the heads up and I appreciate any pictures you can send that show washer and spacer placement, I don't have any lock washers on my box. These are the things I was looking for. It's crazy FIAT did not do an exploded diagram of this but such is life.

Ya, I read all about the blocks being easily cross threaded, plan to finger tighten for a bit. Also plan to use just a dab of anti seize on them.

The spring on the break return has very little tension, no 360 winding to it. Mine was a little rusted and would not even move the pedal all the way back to position. Cleaned it up and greased it well, now works as expect but again very safe to deal with. The biggest pain was removing the plastic shaft from the brake pedal rides on, mine was really rusted on (it's a tight tolerance and the pedal rusting inside cause a pressure fit). I was told do not hit it with a hammer and to use a press but did not have one so users a metal bar, various cut length of pipe and two c clamps to force it out (see below). You definitely want to clean this up get rid of the rust and grease it up well. If not it will pivot the plastic shaft rather than pivoting on it, this in turn will cause the shaft to get cut into by the brake box walls, eventually failing.
View attachment 49489View attachment 49490

Also when you get it apart you can de-rust it to the bear metal by dumping it in a vat of Apple Cider Vinegar, it will eat every trace of rust off it in 2 days. When done wash it in a solution of water and baking soda to neutralize the acid and prevent ant rusting when removed from the vat. Blow it dry with compressed air which will also blow off any loose or loosened paint. This works really well on other parts as well, I've made completely rust covered screw look new. Just be aware that this process will eat away any galvanization protection on a part so be careful with what you treat.
View attachment 49491

Thanks for the info and hints on the pedal pivot arrangement. As my pedal seem to pivot okay....I was tempted to just leave them be....but you are right.....as long as I am this far in...I might as well go the whole way and dismantle everything and clean/de-rust/paint/lube.......oh good more project creep....

As for the washers and spacer on those 8mm long bolts...I took some more pics for you last night. Note all pics are from the underneath as it seemed to show better.

In pic 1 below, the tip of the pencil is pointing to that spacer. Sorry for the crummy pic...but look closely and you can see that spacer between the double distribution box and the brake master. That spacer is about 8mm ID, 16mm OD, and about 8mm thick. As the pedal box has never been touched during my ownership of the car ( since 1988 )...and the way the jumper lines seem to line up perfectly...I'm pretty convinced that is the way it came from the factory. And that spacer DOES appear in my official Fiat parts book as part # 4363364. Mind you...your '85 may well have a different arrangement there...
x19 pedal box bolts 1.jpg


In the pic below....you can see the flat washer ( m8 x 16 ) under the head of each long bolts...that the tips of the pencils are pointing to.
x19 pedal bolts 2.jpg


In the below pic you can see - tips of the pencils again - more flat washers ( not lock washers as I said yesterday - i will go back and edit that ) under the nuts. Again just m8 x 16 flat washers. And my parts book confirms these to be the same flat washer part # as the other washers.


And those nuts are just plain nuts - no nyloc or anything - which seems a bit odd that Fiat did not use a lock washer or lock nut there....I suppose substituting a locking nut there might be a good idea....
x19 pedal bolts 3.jpg


And to confirm...there are NO other washers or spacers anywhere along those long 8mm bolts.

One curious thing..look at the pic below:
x19 pedal bolts 4.jpg

I would think there should be -and even my parts book shows one - some sort of jamb nut where the pencil is pointing to. To lock in the proper adjustment. It would make sense. But no sign of one being there. But I can even see one there in the pic of your pedal box. so think I will add one.....

Hope this helps. Doug
 
Thanks for the picture that is very helpful. I'll be finishing and installing the box this weekend. Good idea to rebuild the complete box, remember that grease is only good for so long. It will eventually separate and stop working. You might be fine today but two years from now it could fail. Best to put new grease in while it is out. I'm hoping this is the last time I have to do this. Thanks again and good luck.
 
One curious thing..look at the pic below:
View attachment 49535
I would think there should be -and even my parts book shows one - some sort of jamb nut where the pencil is pointing to. To lock in the proper adjustment. It would make sense. But no sign of one being there. But I can even see one there in the pic of your pedal box. so think I will add one.....

Hope this helps. Doug
My car had a jam nut there when I bought it in '08:

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