Brake/Clutch Pedal-Box Rebuild Info

Adding a couple more thoughts about rebuilding the pedal box.

Going back to my comment about the line (flare) nuts freezing to steel and iron more than to aluminum. I noticed the threaded holes in the aluminum junction blocks are anodized along with the rest of the blocks. Perhaps it is the anodized coating that helps prevent sticking?

I've been using the really inexpensive flare nut wrench I picked up in Greece a few years ago. It looks like the ones on the Lada website (and was about the same price) - see link below. Having the clamping capability has made a world of difference. It works amazingly well, zero damaged nuts. The unfortunate thing is the one I got has 8 and 10 mm ends, not 12 mm. So the 10 mm side is good for all of the brake nuts, but it does not have a 12 mm end for the clutch nut. I believe the 8 mm end may be good for the bleeder valves?
https://ladapower.com/catalog/lada-2101-2107/brakes-2015-01-20/lada-bleeding-nipple-tool-detail

Regarding the two long bolts that hold both masters (and the junction boxes) onto the box. I like the idea of converting them to allow removal of either master without having to remove the whole pedal box (to get the bolts out). Someone had suggested (sorry I don't recall who) one method of cutting the heads off the bolts and threading the end so a nut can be used. Another suggestion has been to use all thread rod with nuts on both ends. I've tried both methods (one on each of the two boxes I'm doing). Each method has slight pros and cons, but no significant difference really. However one thing I've noticed is it kind of makes it difficult to install or remove either nut without the other one moving (the rod rotating through the other nut). So getting the rod centered or just taking off one side isn't easy. One thought might be to make the rods a little long with extra threads sticking out beyond the nuts (on both sides), so you can double nut one side to hold the rod from rotating (while installing or removing the nuts).
 
Something I mentioned in another thread but it belongs here really.

On one of the pedal boxes I'm rebuilding, the clutch pedal's pivot to the short push-rod (into the clutch master cylinder) was very worn.
Here is what I'm talking about:
027bjk.JPG


That car is the "outlaw" garbage-X so I really did not want to replace the whole pedal. Instead I considered ways to repair the damage and eliminate the extra play it was causing.

One thought was to place a steel sleeve over the pivot (round stump) and drill out the corresponding hole in the push-rod to fit the sleeve's OD. But any attempt to enlarge the push-rod hole was futile. It must be very hardened. I guess that's why the pivot wears instead.

The next approach was to weld extra material onto the pivot to build it up, then grind that back to the same size diameter as the push-rod hole. I hesitated due to concerns it would be too soft and wear away again. But ultimately I decided it would be better than doing nothing and I could not think of a better method to repair it. So that's what I did. Grinding it back to a nice cylinder shape of the right diameter was a long process, taking a little off at a time. I had to add more weld material a couple times to get it even - each time having to go back and grind more. In the end it seems to have worked out. No more play and the pivot does not bind.

The pedal boxes will not go back into the cars for some time while I take care of other aspects. So I won't be reporting any real world use of it till then.
 
wear on the pivot pin for the push rod is common, I usually rebuild with weld (but I use bronze filler rod) and file back to a snug fit, with a good lube it seems to last well.

The other point of wear is the end if the push rod ... or perhaps it's differences in the ends of the master cylinders, but I've found anything more than about 1mm of clearance / play at the end of the push rod where it mates with the master cylinder will feel like half the pedal stroke is "dead" and doing nothing ... several I have welded / lengthened and trimmed back to (again) a very snug fit... several times I made the rod adjustable and lengthened to suit in situ.

and I'm pretty sure the clutch nut is a 13mm.

some clutch master cylinders come with the large nut on the end (which the flare nut screws into) made of brass... I figured this was for corrosion protection with the steel flare nut...OE Fiat this is steel.

SteveC
 
Steve, thanks for the feedback.

Good to hear the welded pivot pins seems to hold up. I wasn't sure if it would be hard enough to deal with the load and wear. I forgot to mention it, but another idea I looked into was to completely replace the pin on the pedal arm. But it is not easily removed without causing other damage, and sourcing a suitable replacement piece may be difficult.

Regarding the lengths of the push rods/masters. Luckily I found them to be pretty much equal on both on these boxes. But I agree that rod should be adjustable. You can adjust the free play by moving the pedal stops further in, but that changes the pedal position. I can see how that could be really awkward if the two were very different. But even if they are not, the pedal position would ideally be a separate adjustment from the master free play. I think mine are close enough that I will not need to modify the push rods, but if I do then I'd opt to make them adjustable like most other vehicles have.

And you are correct, the line nut on the clutch has a 13mm head....I was erroneously saying 12mm which is the thread size. Thanks for the correction. By the way, that 12mm nut is much more difficult the source than the 10mm ones.

The large end piece on my clutch masters are steel. But the more I work on the hydraulic systems and think about things, I don't believe the type of metal (steel, aluminum, iron) really is the issue with fittings freezing. Although the anodized coating on the aluminum may help, I found many nuts in other metals that did not cause problems during removal. In my case the biggest factor seems to have been the type of wrench used. That one I mentioned with the pinch bolt to clamp the wrench jaw tightly on the nut has a 100% perfect record for the 10mm nuts. Not having that style of wrench for the 13mm nut (I have a standard flare nut wrench) lead to destruction of them.
 
Regarding a coating to protect your newly rebuilt pedal box from brake fluid and rusting. I did not think to try this on mine (I certainly would have), but maybe some of the plastic spray coatings will work? I'm referring to this type of product:
black-matte-plasti-dip-rubberized-coatings-11203-6-64_1000.jpg

Although they can be peeled off when relatively new, the longer it is left on the more permanite it becomes. Being a rubberized plastic product it might resist brake fluid very well. And I even have a can of it that's been sitting on a shelf waiting for an excuse to try it. But I'm not going to disassemble everything to refinish it now.
 
So I'm using my shelter-in-place time to work on the hydraulics and got the pedal box out. I ended up using my harbor freight flare wrenches for the hard lines and they worked great. I expected brake fluid to come out of the brake lines, but actually an amount of water came out. The old reservoir in the car was cracked and exposed to the elements so I'm guessing that's how it got in.

Question - is there anything that is supposed to go on the threads of the hard lines when this gets reassembled, or does it just screw in as is. Thank in advance. -Mike
 
Question - is there anything that is supposed to go on the threads of the hard lines when this gets reassembled, or does it just screw in as is.
Mike, although you did not seem to have much issue removing the flare nuts, typically they get seized and result in a lot of damage when removing them. So it is generally recommended to put a bit of "anti-seize" on the threads when installing them, to prevent problems in the future. But nothing is required for sealing purposes.
 
That pedal box looks pretty nasty - make sure that rust on top doesn't perforate the box. You may need to reinforce it otherwise.

Adding anti-seize honestly doesn't do much, since brake fluid is goign to wash most of the fitting when you bleed them, which you should, working out from the MC, ending at the caliper bleeders.
 
bleed them
Interesting, assuming this is what you mean. I have never bled each fitting, only the whole system at the two ends. That applies to every hydraulic system I've ever done. Honestly that seems like a big mess to me, and I've never found any reason to do it (meaning I'm able to bleed the system without cracking each joint). However I agree that if you prefer to bleed each fitting then it will cover the threads with brake lube, which might do a similar job of preventing freezing(?).
 
Interesting, assuming this is what you mean. I have never bled each fitting, only the whole system at the two ends. That applies to every hydraulic system I've ever done. Honestly that seems like a big mess to me, and I've never found any reason to do it (meaning I'm able to bleed the system without cracking each joint). However I agree that if you prefer to bleed each fitting then it will cover the threads with brake lube, which might do a similar job of preventing freezing(?).

Given the layout of the X1/9 system, it gets the air out at the beginning of the circuit rather than pushing it all the way through. I do this on any car though, bench bleed the MC, then bleed the lines at the MC, then bleed the calipers if needed. When I put my pedal box back in, I only bled the lines for the clutch & brakes at the MC line fittings, that was all that was necessary.

What I meant was that the brake fluid would tend to wash off the anti-seize :D
 
Just finishing this projet myself on the the first of two cars. I painted the Master Cylinders with caliper paint. The originals had a lot of surface rust, and were generally nasty. Not that it will make a big difference, but at least they look nice now. The brakes bled easily for me, but I'm still having a bit of an issue with the clutch. The nipple on the slave cylinder is really small and shallow and I'm having a tough time getting a fitting for my vacuum bleeder that fits snugly. Probably just some aquarium hose fitted in a manner to not let air back in would work better than what I have.

I didn't bench bleed the MC's as Hussein did. I don't see how you could do that and not wind up with brake fluid everywhere. Hussein, you are way more talented than me :)

One last thought is that the clutch reservoir is really small and it's easy to drain it before you have all the air out of the system. Check it frequently so you don't have to start all over with the bleeding process again.

Sorry, I keep thinking of things. The reservoir hoses are two sizes. I used Tygon for the clutch, and brake fluid resistant hose from a BMW parts vendor I found on Amazon for the brakes which looks similar to the factory hose. It's covered with black braided cloth. It was much cheaper than the VW vendors had, and black rather than blue in color.
 
So I'm putting together my pedal box, and one of the hard line nuts will not go into the new brake master. I don't see any casting errors on the hole. Is this something that happens, and if so, does anyone know the remedy? I tried test fitting the nut from the other end in that hole and that goes in fine. The nut also goes into the old master ok.
Master Line.jpg
 
You might be getting some binding from the angle of the line that you are trying to seat in there. I found if I loosened up the other end of the line I could manipulate it enough to get it to start and then could snug down both sides. They can be really difficult.
 
You might be getting some binding from the angle of the line that you are trying to seat in there. I found if I loosened up the other end of the line I could manipulate it enough to get it to start and then could snug down both sides. They can be really difficult.
Exactly. The angle of the line isn't allowing the thread to catch. Take care to avoir stripping it... :eek:
 
Thanks for all the advice. I eventually got it to go by slipping a smaller flair wrench over the nut and applied pressure while turning the nut with another wrench. I also took out the connecting bolt to the small box and got both lines on and then reinserted the bolt which gave me more wiggle room. Box finished!! Here's the after and the before. I'll drive this car yet!!
IMG_20200406_183226.jpg
Pedal Box.jpg
 
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Just a little tip - maybe too late - sorry :oops:. Use all thread rod to hold both master cylinders on. You have to drop the pedal ass. to get brake master off with that long bolt because it'll hit the center stack (console) and won't come all the way out if you don't drop it.
All thread makes it possible to get the fastener out of the way so that both of the masters can drop out without removing the entire ass.
 
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