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Sam Buchanan

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Sam Buchanan last won the day on May 16

Sam Buchanan had the most liked content!

About Sam Buchanan

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  • Location
    north Alabama
  • My Project Cars
    1948 Plymouth Special Deluxe;
    1974 Standard VW Beetle;
    Vans RV-6;
    Fokker D.VII replica


  • Location
    north Alabama
  • Interests
    custom-built aircraft

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  1. The nut will thread onto the rear axle just as it does on the front.
  2. Yes, new and purchased from an Amazon vendor, also available at McMaster Carr. It is 3/4"-16, you might find one at a good auto supply house or in the axle nut junk box of a gearhead. If using an experienced axle nut be sure the threads are still tight. The big-box stores will probably only have the course-thread 3/4"-10.
  3. In a previous thread I showed how I made a brake adjustment tool using a length of steel tubing, some all-thread and a piece of angle. The tool worked fairly well but had some inherent imprecision due to the tubing not being a real tight fit on the axle threads. This was really obvious on the rear axles due to the threads being worn. I've modified the tool and it now works very nicely and accurately. Instead of the all-thread being welded to steel tube, it is welded to a 3/4"-16 nut. This removes any significant play in the indicator. Before removing the wheel drum, one minor cam adjuster is tightened enough to create noticeable drag on the drum. The drum is then removed and the brake tool is threaded onto the axle. The pointer is located over the portion of the shoe that contacted the drum which indicates the ID of the drum and adjusted for a snug fit on the shoe. If you want to get really fancy a 0.006" feeler gauge can be inserted between the pointer and shoe. I tried chalking the shoe to assist with indicating the high point during the initial adjustment but didn't find it to be of any advantage. Notice how these brand new shoes have not yet worn enough to have full contact with the drum. I'll readjust the brakes after some miles have accumulated on the shoes. Once the pointer is adjusted to match the high point of the shoe that was adjusted against the drum, the tool is swept over each shoe so the major and minor cam adjustments can be set so each shoe is concentric with the drum. Hopefully this will remove some of the mystery of adjusting the brakes and provide visual confirmation of proper adjustment.
  4. I don't care to get mired in this discussion (much rather discuss old cars....) but as a retired small business man I wish to offer a couple of comments. One, I think James is painting with a very broad brush. Yes, he is frustrated due to not receiving the engineering input he desired, but I think a major factor is his request for "something odd". By definition, a small business must be very focused on their specialty in order to survive. In my previous small business life I would have been very reluctant to engage with a customer who requested something totally out of my normal work flow. This didn't mean I didn't have an interest in helping, I just couldn't sacrifice my customary attention to regular customers with my limited resources in order to run down a rabbit trail that wasn't in my wheelhouse. Two, there are tremendously dedicated small businesses in many countries, especially the USA, providing fantastic service. That is how they survive! To insinuate poor service is somehow related to nationality is a train of thought I find hard to follow. I also suspect there may be a generational component to Jame's disenchantment with American small businesses. There, James is probably hacked off at me now.....and I've elaborated all I intend to do. Now...back to our regular programming.
  5. The one in the middle appears to have one of those air conditioner things that folks used to attach to the passenger door....
  6. Thank you for the offer, Sharps, I'll keep it in mind if I need to pursue it.
  7. That's good to know, I'm sure one will turn up if/when I decide to replace the one I have....just not sure the threads will hold full torque next time I pull the drum.
  8. The threads on one of the rear axles on my '48 P15 have suffered considerable abuse and are pretty thin. Where would be a good place to look for a replacement axle shaft or can a machine shop weld and rethread the axle? Anyone have experience with a similar situation?
  9. Yes, the smaller cylinder will have less volume per given travel but yield greater pressure. I haven't explored the travel of each chamber of the new MC so don't know how displacement compares with the standard cylinder. The brakes were carefully adjusted for minimum shoe travel. Thank you for the reply, all thoughts are appreciated. I really want to figure out how to make this work.
  10. I don't really understand why the new MC didn't work either. First thought it was a bleeding issue but after running a quart or so of fluid through it never could get a pedal. The MC appeared to be pumping properly.....sort of a mystery. I even tried the front brakes without the residual valve but that didn't help. I suspect the problem is something simple but I couldn't nail it down. Since I have all the mechanicals done I may try again with a different cylinder when I feel energetic enough.... I cut a hole in the floor for access to the new MC. It would have required a cover with a slight dome shape but is mostly under the front edge of the seat so wouldn't be a problem. The geometry of the pushrod is such that it doesn't touch the old cylinder even at full travel.
  11. Well....this is not the update I wanted to make. In spite of many attempts to bleed the brakes I was unable to get a satisfactory (hardly any) pedal with the dual-chamber master cylinder. I used to tell my science students that because an experiment didn't have the anticipated result that there was still knowledge to be gained. I suspect the cylinder I used didn't have sufficient displacement. It is a 1" bore and maybe a larger bore cylinder is needed since the standard cylinder is 1 1/8" bore. I reasoned that 1" was sufficient since each chamber was only pushing wheel cylinders on one end of the car but that must be faulty reasoning. However, mechanically the mod worked flawlessly, the bracket and pushrod were an excellent setup. All that is needed is a master cylinder that is compatible with the P15 wheel cylinders. I wimped out and installed a new standard cylinder which bled as expected. I'll ponder this some more and may revisit the mod at a later date.
  12. This tool has been improved and updated and can be found in this thread. Like many newbies to the P15, I'm finding the brakes to be the most frustrating aspect of an otherwise simple vehicle. The absence of a factory adjustment tool certainly adds to the uncertainty of setting up the brakes in addition to not having prior experience with the Lockheed brakes. I filed flats on the ends of the anchor bolts so they can be adjusted with the drums in place but I just wasn't confident the shoes were concentric with the drums. The tool below is one I fabricated from scrap material in the shop and it provided visual confirmation that the shoe adjustment was close to what it needed to be. This is not an original idea and many of you may already have something similar, just want to toss this out for those who are struggling with brake adjustment. The tool is just a length of .875"x.059" steel tube with some 1/4" all-thread welded to it. A short length of aluminum angle forms a pointer than can be adjusted via the nuts on the all-thread. The tube is a close fit on the 3/4" spindle. With the drum in place one minor adjustment cam was set so the toe of the shoe barely dragged. The drum was removed and the pointer on the tool adjusted so it barely touched the toe of that shoe which is a close approximation of the ID of the drum. It is then just a matter of sweeping the tool over the shoes to adjust them so they are concentric to the drum. It turns out the method I had used to adjust the anchors and cams with the drums in place was pretty close but this added visual confirmation. I don't have the rear brakes opened at the moment so can't recall if the same steel tube will work on the axle. The tool could also be built by welding the all-thread to a spare axle nut.
  13. I recently added directional signals to my '48 P15 with the same switch. Be sure the flasher and the Signal Stat have excellent grounds. Do the brake lights still function? If not recheck the brake switch wiring and the connection you made at the switch. Stay with it, you'll figure it out.
  14. When the '48 Special Deluxe sedan followed me home one of the first mods that came to mind was changing the standard master cylinder to a dual-chamber cylinder. Since the time in my very distant youth when my 1963 VW Beetle rolled into an intersection when a brake line let go I have been very wary of single-chamber master cylinders. I first checked with ECI to see if their master cylinder retro-kit was suitable for drum/drum brakes and was informed it was only for disks/drums. My hours spent researching the forum archives uncovered a photo of a retro-fit that formed the inspiration for this conversion. I don't recall who posted the photo....but Thank You. I'm including some in-process photos and will update as the conversion is completed. If anyone sees any gotchas feel free to wave a red flag. Here is the retro-fit as it stands this evening: The new cylinder mounts behind the body of the old cylinder and is activated by a pushrod running from the brake pedal through the gutted old cylinder to the new cylinder. The pushrod was fabricated with a combination of 5/8" steel tube and the ends of the old pushrod: It seems the original pushrod components are not easily replaced so this will allow them to be put back in service if a standard cylinder is used at a later time. A 7/16-20 nut was welded to one end of the tube and a 7/16-20 bolt to the other. This allows the pushrod length to be adjusted for proper pedal free-play. Below is the new master cylinder bracket, it is 0.090" steel and through-bolted to the frame rail:
  15. The saga continues......received a little bag of #12-24 filister-head screws today, rushed breathlessly out to the Plymouth to replace the carb bowl screws and.....no joy....turns out the screws need to be #12-28. Started looking and #12-28 screws like the ones in the carb are nearly unobtainable. There are a few socket-head and brass screws in this size but it seems this screw went out of style with '78's (records). One of the holes in the carb bowl is missing about 3/4 of its threads and that's why I wanted to find some slightly longer #12's. It looks like the best option if the rest of the threads pull is heli-coils with modern threads. This is the charm of old cars.
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