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Thread: Fabricating Brake tower parts

  1. #1
    Join Date
    Apr 2021
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    SF Bay Area
    Posts
    97

    Default Fabricating Brake tower parts

    Hello Rovers!

    I am in the middle of a single-line to dual-line plus Power booster upgrade on my 1973 series 3, 109" RHD truck. I'll do a comprehensive post when I'm done as I think people might find it interesting to see the costs and challenges. But here's a little one to give folks some initiative:

    I have been scouring the parts catalog and all the usual vendors(including our hosts) in this list:
    https://forums.roversnorth.com/showt...-a-small-world
    ...and no one seems to make part#592567! It's a little spring arm that levers up and pushes the brake switch on the power booster brake tower.(See my image from the Parts catalog). Such a tiny, insignificant part...but it stops the build!

    After your encouragement on my last discontinued part, I decided to fabricate one! If you have this same problem, here is a breakdown of the steps. Took about 30 minutes and let me continue the build.

    1) Source a piece of steel or aluminum stock, about 3/4 inch wide and thin enough to bend/shape on the vise, but not bend by hand. Use the hinge fitting on the plate (AEU 1468) as width.
    2) Also, get an aluminum spacer or small tubing to keep a nice round fulcrum for the new spring arm. Home Depot has both of these.
    3) Use vise to clamp about 1/4 inch of aluminum stock. Use a carpenter's square so you know you are clamping exactly 90 degrees, or you will roll the aluminum like a cresant roll and be unhappy.
    4) Use a hammer and roll it 90 degrees.
    5) Get a drill bit of approximately the same size/radius as your round stock spacer. Clamp it into the elbow of the bend you just made, in the vise. Use the square again to make sure your stock is 90 degrees in the vise jaws.
    6) Use hammer or vise to press the aluminum stock around the drill shank, forming a round over that the little tubing can fit in.
    7) Put the tubing/spacer in the newly formed round fulcrum. Congratulations, you've made a tiny leaf spring! Use the vise and hammer to tighten up the fit, being careful not to crush the tubing and make it come out-of-round.
    8) Cut the width of the tubing to match the inside of the hinge hangers on the plate. Put it in there and use a Cotter pin to secure it in.
    9) I had no idea of the length, so I cut it long. You can trim it later. The final length is about the same width as the mounting plate(see parts catalog diagram). You should also put a slight bend at the end to make it easier to install in the brake tower.
    10) Test fit. I had to remove the vacuum diaphragm to install it. There just wasn't enough space to get the plate on and even reach the front 2 mounting screws with the diaphragm on. This was easy for me with new parts on the bench, but would be annoying in the car. Watch those tiny screws! You drop them and they vanish from the universe...
    11) Adjusting and testing. After I assembled everything and screwed the new switch in, it didn't really have the range of motion I expected. I mean that the action of the brake pedal didn't lever that little are as much as I thought it would. That image with my fingers cycling it...yeah, it only goes through about 1/4 that range installed in the tower. So, that means it's about proper adjustment to get the switch in the right range.
    12) I hooked up a voltmeter and set it up to measure resistence(Omega setting). The next part is finicky, because you need 4 hands. But, some lead clips or female electrical connections help hold things while you move the brake pedal. This might be easier installed in the car, but I did it at the bench in case I had to disassemble everything again. Luckily, it was not that bad, and just involved spinning the switch in or out until the range of motion matched the open-close circuit of the switch. It was a bit tight. The actual range on the brake switch is about 1/2 turn. So, if it's in too far...the brake light would be on the whole time. If it's not in far enough, the light never comes on. That difference is a half a turn. So, I backed it off a 1/4 turn and got it in a decent t range. I'm still not happy with it...so I'll adjust it further on the car, with the lights powered and the brake lines full and pressurized. Right now, on the bench, I have to push the pedal down almost 1/2 way through for the light to switch on. That feels excessive...maybe might not come on in light tapping. But then again, it may feel different in actual use. I used to have to hammer on my old leaky brakes to even do anything, so it's probably reasonable on Series trucks that you're half way through the travel of your brake pedal before it starts grabbing. I can adjust when I get it in the car. Just mentioning it here as a "pre load" kind of step...just getting it "in the ballpark" before final assembly.

    So, that's it! It works. There are two other places for these brake switches, depending on your package options. Folks with single line systems will have an in-line pressure switch at one of the front junctions. Also, the non-booster brake tower has a switch at the front of the pedal, like modern cars. I was going to do that, if this didn't work. But trying to keep things stock and somewhat matching the parts catalog. So far, I'm happy with it. So if you have a similar need, you can try this.

    Oh, also need to mention that the booster brake tower is a repro one fabricated by Pangolin4x4 as its also a discontinued part (but available at their website).

    Now for pics!
    Click image for larger version. 

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    1973 Series 3, 109

  2. #2
    Join Date
    Dec 2010
    Posts
    160

    Default

    gawd !!! such ambition, good job but i would have a harder time dealing with installation of the lines .......... keep posting as I'd like to see how you deal with that.
    thx,

  3. #3
    Join Date
    Apr 2021
    Location
    SF Bay Area
    Posts
    97

    Default

    @jimrr:

    I have been researching that A LOT! I'm sure you've seen my other thread:
    https://forums.roversnorth.com/showt...-Valve-bracket

    But here is my plan:
    1) PDWL Shuttle valve) I don't care so much about the dummy warning light on the dash. But the shuttle valve is needed as a safety device to separate the two lines(front and back) in case of a catastrophic leak. So, this is more plumbing than electrical(for now). It just replaces the 3-way tee that usually is below the master cylinder, screwed to the frame. Easy.

    2) PDWL 4 or 5 way) These come in two flavors...one with 4 holes arranged like an "H". And ones with 5 holes, with an extra line out towards the front. Lots of options here. I have seen parts manual and repair manuals show various piping diagrams. The thing that settled it was a diagram of the PDWL valve cut open. Basically, the valving is pass-thru...so the two lines systems are like the legs of the "H"...it comes in at the top, and exits the bottom...and the horizontal bar of the "H" is the valve that slides forward or back to close one or the other. The 5 hole PDWL just has an extra line for the front...so you could do two separate brake lines for LF and RF. The parts manual shows a plug #NRC4137 that can block that hole...essentially letting you use a 5 hole PDWL valve as a 4 hole. So, they are interchangeable. Done. Why use either? See next point...

    3) Front brake lines - Single or double?) The reason you have 4 and 5 hole PDWL valves is if you want to run separated Left and Right Front brake lines from the PDWL Shuttle valve. If you want to run two parallel lines out of the PDWL valve, going forward to the wheel well, then each going to their wheel...use the 5 hole PDWL. If you want to run a single line going forward on the frame, then have a Tee piece split that line once you get to the near side wheel well...use the 4 hole PDWL. That's it. Or, use a 5 hole PDWL and plug the front hole. It comes down to how you want to run the brake lines to the front. Both ways are valid(both in LR authorized publications).

    4) Separated lines or single with Tee?) So the decision becomes, how to route brake lines in front? I don't have a nice flaring tool. A good one is $170-$300 to get professional double flares 100% of the time. I'm not messing around with cheap tools and having to re-shaoe and cut and flare a bunch of lines because I messed up. I found pre-cut, CuNiFer lines already flared and order by LR part number at John Craddock. I think our hosts also sell nice kits of precut lines. For me, I'd rather spend $200 on lines than $200 on tools and be frustrated. Usually, I'm the other way around...but I don't plan on opening up a brake shop...so I'll need to make like 6 flares and them be done...so that's like $50 a flare. Not worth it. The pre-cut lines are like $15-$30 each. Done.

    I decided to go with the single front line out to a Tee that splits Left and right lines. So, 3 shorter runs of pipe instead of 2 long runs. Why? Well, after messing around with bending and shaping the pipe connecting the wheel cylinder...I realized that trying to shape a 8 foot long, complicated shape around my frame and existing parts is a fool's errand. I could do it, but I'd probably mess up 2 or 3 times...and have to order spares(not bad idea). So, shorter runs are easier to install and service. People could argue that adding extra connections increases areas it could leak...but, I think having better access to it means you can service any leaks or replace sections sooner and easier than a single long run. Also, you can bend and handle a 3-4 foot section easier. So, I am going with the single line out the PDWL into a Tee at the front.

    Mind you, the PDWL valve only has two circuits- front and back. Even if you have two lines coming out the front...those two lines are on the same circuit. You're not getting 3 circuits protection. So if you develop a leak in the left front...the right front goes out, too. So, the plumbing is just about convenience and servicing at that point.

    So that's the plan. It will look exactly like a single line plumbing after the PDWL valve. The only difference is between the PDWL valve and the master cylinder...where there are two circuits(imagine the master cylinder sitting on top of that "H", and then the bottom legs of the "H" go front and back.).

    Make sense?
    ...┌───────┬──,,
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    ...d ..__ ......... |... | ..__....p
    └/ | \────┴──┴/ | \─┘≡
    ..../..@........................@

    1973 Series 3, 109

  4. #4
    Join Date
    Dec 2010
    Posts
    160

    Default

    really, i think that's just the way i'd do it too but i'd probably screw up 75 ft. of brake line trying to make it one piece!, in thinking of this situation the other day i realized my series 2 has the old system in it. further more, to move it last time i had to open the rf bleed valve which had locked the wheel. I believe this caused by the master cylinder but i never looked at it, just swore to remember that i don't have brakes after driving it a couple weeks ago and having forgotten!
    All in all Vlad i'll probably not change it but think about keeping oil off the E brake. I don't think my series 3 has had a E brake in 20 years! ..... I think I had the xmission out in the early 80's in seattle and didn't even know about centering the shoes on the E brake though I remember puzzeling why it was mentioned in the original factory manuals I got in 1976 for like $80 on army pay from the seattle dealer!
    anyway, they're covered in 90 wt. oil now as it needs a new seal and probably the bearings tightened .......... all part of the plan dont'cha know? !

  5. #5
    Join Date
    Apr 2021
    Location
    SF Bay Area
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    Default

    Had a nice weekend of work. Here are some pictures of the old system and the new system.

    Old, single-line system. Also, the old drums and some suspension bits I replaced recently:
    Click image for larger version. 

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    The new dual-line system, with vacuum power booster and new brake tower. You can see the plumbing layout:

    Also, isn't it the unexpected things that take forever!? My firewall/bulkhead is so rusted. But I don't want to replace it just yet...so I had to fabricate a backer piece to sandwich the rusted mounting area...to stabilize and reinforce it:

    And, because folks talk about this...I can confirm the 8" Booster Diaphram and Series 3 Tower fit without cutting the fender(wing) and the standard hood(bonnet):
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    ...d ..__ ......... |... | ..__....p
    └/ | \────┴──┴/ | \─┘≡
    ..../..@........................@

    1973 Series 3, 109

  6. #6
    Join Date
    Dec 2010
    Posts
    160

    Default

    looks like a class act vlad, real nice.

  7. #7
    Join Date
    Apr 2021
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    SF Bay Area
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    97

    Default

    Oh boy...

    Another 2 weekends spent under the Rover, working on brake lines this time. I'm rethinking my whole approach. I thought I'd share, in case someone is doing something similar.

    I was trying to avoid buying $200 of specialty flaring tools, and spending time measuring and cutting, prepping lines. I bought Land Rover part number pre-cut and flares lines instead. I picked the ones out of the official parts catalog...matching part numbers to get a "factory" engineering, I assumed. Well, I had mixed results:

    1) The front lines LH & RH to the "T" fitting went in okay. Since they are pre-cut and flared, they come a little long, so that you have a little wiggle room for custom fit. Well, they were about 6" too long. So, I had to put a needless "Z" in them to take up the slack.

    2) The one going from the "T" junction to the PDWL valve was about 1 foot too long! I ended up putting a gentle loop about 4" diameter to eat up the slack. This looks wonkey...and I had other problems that means I'll have to throw put this line...(more).

    3) There are about 4 setups shown in the Parts catalog for this dual-line setup. There are some with the PDWL valve flipped upside down...and some with it rotated back-to-front. I didn't think it mattered, but it DOES! The thing that matters is that PDWL/Shuttle valve has different threaded holes in it on all sides! So it matters what your brake lines are, and what the lines from your Brake MC are!

    I'm doing all new parts, so it should just work, right? Wrong. I'm all in the British, SAE standard, bubble flare...but it's still a mess.

    The "top" 2 ports of the shuttle valve are 7/16"-20. The "bottom" 2 ports are 3/8"-24. The 5th "front" hole is a 7/16"-20.

    My "rear" line nut(going to rear brakes) is 3/8"-24.

    My new "front" line nut is 7/16"-20.

    But, the crappy part...the "front" line nut is a short one. It won't seat fully. The threads stop, and the line is still loose. So after bending it all up and installing, it won't seat. I needed it to have a long thread. I think it was meant to go into a 3-way "T" instead, which is shorter?

    So, the LR part number shows interchange...but the reality is different.

    So here comes the wisdom:
    * Don't bother with pre-cut lines!!
    * They are almost impossible to get alignment and length right (unless pre bent for your exact car, too).
    * They are not guaranteed to have the right flare nuts size on them(often not listed online).

    So, I ordered 25 feet of new CuNiFer line from Fedhill, along with EXACTLY the flare nuts to spec, and a solid bench flaring tool, pipe cutter and deburring tool. In the end, custom lines are the only way to go to guarantee you get exactly what fits.

    * Also, don't buy a Land Rover. But if you're reading this, welcome to the club of frustrated DIY mechanics.
    ...┌───────┬──,,
    ...|______OD__|__\\_____
    ...d ..__ ......... |... | ..__....p
    └/ | \────┴──┴/ | \─┘≡
    ..../..@........................@

    1973 Series 3, 109

  8. #8
    Join Date
    Apr 2021
    Location
    SF Bay Area
    Posts
    97

    Default

    Another weekend with the Rover project.

    The brake flaring tools and 25' coil of CuNiFer brake tubing and fittings came in the mail, so I set to work making custom lines. I can say it went really well...so much better than last time with the pre-cut lines. Having extra tubing and all the tools to make custom lengths and cuts really makes a difference.Each tube is exactly the length it needs to be, and cleanly run. No zig-zags to reduce excess length or needless loops.

    I sort of learned a neat trick for measuring runs of tubing and custom shaping. I got some 1/8" aluminum Armature Wire from the art store. This is the stuff you put inside clay sculptures to give them structure while you sculpt...like rebar in concrete. Anyway, it's super bendable by hand and stiff enough to hold a shape. I got a 15 foot roll for like $7. And I also got some thin tape (1/4 inch) at the Art store, too. Most tutorials say to use a coat hanger or garden wire or soldering lead to bent out a pathway for the tubing...so you can get the shape you want. Then, you pull it straight and measure it to know how much tubing to cut. But then you have lost the custom shape!! My trick is, put that tape on the aluminum Armature Wire every 6" or 1' to about 4 feet of Wire. Then, get under the car and bend the Wire into the exact shape you need.. Then, bring the bent Wire to the workbench. You count the number of tape stripes and that is your lengthy! No need to straighten it out. You now also have a custom template. Cut your tubing to the exact length (add 1/2" for insurance) and hold it up to the template to get the exact bends you need. Then, take it back to the car and you have perfect lines, bent exactly to fit the car!

    The only other tricky bit was making sure to plumb the correct lines from the master cylinder. I have a 109" Series 3, and the front brakes on those have 2 wheel cylinders each. So the volume of fluid is higher for the front circuit. Had to triple check the diagrams and forum posts. Thank you Terry Ann for a great website. The LR manuals are not very clear on this, but on the 109...the hole closest to the vacuum booster is the primary valve with the larger volume of fluid. So, it MUST go to the front. That means the back pipe on the MC goes to the front circuit. The diagrams in the Parts catalogs show that PDWL/Shuttle valve swapped every which-a-way!! But the takeaway is - larger volume to the front circuit. I guess on the 88" MC, it's flipped...with the larger volume on the front hole in the MC. So the flip flopping in the PDWL valve is to account for this. Both sides are identical in the PWDL valve, and you'll see either the lines above it(to the MC) do a swap before coming in...or the bottom is flipped and the line going to the back brakes is plummed to the bottom front of the PDWL valve. I ran mine with the outgoing lines front going front and back going to the back brakes and did the cross over at the top(see pics).Click image for larger version. 

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    Also, the flare nuts on the MC are two different sizes...probably so you don't mix them up on disassembly. The tubing is the same size(3/16" or 4.75mm) but the flare nuts are different. The rest of my lines are either 3/8-24 or 7/16-20. One of the MC holes is 7/16-20(rear) and the other one is larger, FYI.

    I got some nice aluminum spacers from Jegs for 3/16" tubing to finish off the install. They were more than the tubing($20 for 3) but I think look sharp.
    ...┌───────┬──,,
    ...|______OD__|__\\_____
    ...d ..__ ......... |... | ..__....p
    └/ | \────┴──┴/ | \─┘≡
    ..../..@........................@

    1973 Series 3, 109

  9. #9
    Join Date
    Dec 2010
    Posts
    160

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    i'll need this info, thx,

  10. #10
    Join Date
    Oct 2007
    Location
    Gig Harbor,Wa
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    30

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    Looks really nice! Reminds me that I need to re-do mine. Like the spacers! Looks professional....
    Erik Peterson
    Gig Harbor, Washington
    '69 SWB Soft Top 2.25 petrol LHD
    '71 LWB 2 Door 2.25 petrol LHD

    "Every trip is an adventure in a Land Rover".

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