1950 P15 Dual master conversion. The Bracket,

[cdnpont]

Thanks for all the help and ideas in my previous posts guys,

 

A little progress in the project. I now have a bracket made up, 1/4" plate. Drilling the 1.5" hole in the face was a challenge, but this cheap carbide metal hole saw made quick work of it in the drill press. Be sure to adjust your speed to around 300, and keep steady pressure on it with light oil. Amazon part.

 

Now Mocking up the mount position of the adjustable valve and residuals, trying to find the best spot to allow easy connection to existing (or new if Req.) main lines. I'll mount the adjustable valve knob inboard, thinking for protection and ease of adjustment from the down on the lawn lol. The idea is to use a good existing stock front bellows seal, and drill a drain hole in the bottom of the old core as a drain should water get in. Not likely as the car is dry driven only.

 

Using a fancy little 8an hose separator to mount the checks. A little nicer that having them hanging free I figure. A tiny bit of tape on the Wilwood valve and they clamp in tight. Amazon part.

 

The entire main bracket can be moved forward and back on the original master, as all 3 bolt holes in the side plate are slotted. This movement should  easily allow the faceplate to meet and bolt to that frame box back surface as required. Again, I we had the car here, this wouldn't be an issue. As a bonus, we'll be able to pull the new master forward into close contact with the old, and should allow us to place some kind of simple DIY rubber seal between the two.

 

The provided Wilwood pushrod comes way forward into the old core, so not much of an extension bar will need to be made. Maybe 4.5". Nice.

 

Cheers, Mark.

 

 

 

 

[D35 Torpedo]

I like it!

[Semmerling]

Nice clean work, well done. 

[cdnpont]

Thanks Guys, 

I now have myself wondering if we couldn't have included a 7" power booster under there as well. Probably too tight to the floor along the master centerline though. 

I see you can buy entire booster/master kits with a pedal. Too much work to fit a different pedal, along with fitting the clutch pedal I'd assume.

 

 

 

 

[Sniper]

Small boosters make small power.  Might look at what the output is and see if it is enough?  Last time I looked I seem to recall 800 psi was the output, not really enough for discs which is what I was looking at, or older non-self energizing drums.  But that might have been the single diaphragm setup, Speedway sells a dual one that might be the ticket.

 

I've attached an interesting spread sheet that will allow you to see the differences.  Not my spread sheet so I make no claims as to it's veracity.

Manual v Vacuum - uhcoog1.xls

 

That mount looks slick, but I wonder about one thing, it appears to be a T, will it work back and forth under use and eventually break?  Could a gusset top and bottom be fitted and would it help?

Edited April 26, 2023 by Sniper

[Sam Buchanan]

1 hour ago, Sniper said:

 

That mount looks slick, but I wonder about one thing, it appears to be a T, will it work back and forth under use and eventually break?  Could a gusset top and bottom be fitted and would it help?

 

I noticed the same thing but didn't mention it because I didn't know if maybe the 1/4" steel might be stiff enough and it isn't cantilevered very much. But I had the same concern with the mount I built from lighter material and could detect a minute amount of flex. I added a brace to remove the possibility of fatigue of the bracket. A gusset on top of your bracket would do the trick. 

 

Edited April 26, 2023 by Sam Buchanan

[cdnpont]

Thanks Sniper and Sam,

 

I agree a single diaphragm master might not be worth the trouble. But I do know they make a dual diaphragm compact 7" Booster. Does that double the assist?

 

I kind of visually estimated (from images only) the distance from the master centerline to the floor and it can't be much more than 3". The issue is a dual 7" booster is really closer to 8" in diameter at the locking flange. I guess if thee was a will, there'd surely be a way. Like make a hump in the floor under the drivers seat...

 

I did originally think of leaving the bracket to basically float from the side of the master only, and would have built in more gusseting (still might). But we will be through bolting the new master, new bracket and frame box together. This should tie it together on the outboard side.  

 

Edited April 26, 2023 by cdnpont

[cdnpont]

Oh, one thing I only just noticed is the two lower bolt holes for the master are offset horizontally. And don't laugh at my DIY slots!.

 

Pre drilled everything. I then welded the one 2 hole side section square to the face plate, bolted it onto the old core, with the new face square to the old, then bolted the small rear extension on, lined the gap up, then made that weld joint.

 

Was looking at it today, and thought, hey, I screwed up, the holes are way off! Looking closer, turns out the front bolt boss on the original master is lower then the bottom rear being square to the end cap.

 

Small thing, 

 

 

[nonstop]

14 hours ago, cdnpont said:

Thanks Guys, 

I now have myself wondering if we couldn't have included a 7" power booster under there as well. Probably too tight to the floor along the master centerline though. 

I see you can buy entire booster/master kits with a pedal. Too much work to fit a different pedal, along with fitting the clutch pedal I'd assume.

 

 

 

 

On my 1954, I used a dual diaphragm 8 inch booster.  I used an adapter from speedway to mount the booster.  The difference with mine was I used a bracket from ECI for my application, so I am not sure if it lowered the master at all.  I had started with a 7 inch, but not enough assist.  I really like how my brakes feel now.

[Sniper]

Was that a 7" single or dual booster?

[vintage6t]

18 hours ago, cdnpont said:

I now have myself wondering if we couldn't have included a 7" power booster under there as well. Probably too tight to the floor along the master centerline though. 

 

Here's one way to mount a booster. Not on the original center line though.

 

[cdnpont]

Great info. Thanks guys.

 

To be realistic, on this round we won't be doing a booster, but now I'm second guessing our choice of master bore size at 1 1/8" which is another subject all on it's own.

[D35 Torpedo]

10 minutes ago, cdnpont said:

Great info. Thanks guys.

 

To be realistic, on this round we won't be doing a booster, but now I'm second guessing our choice of master bore size at 1 1/8" which is another subject all on it's own.

Are you running four wheel drum?

 

We got a front disk conversion kit for a 65 Valiant at work. I have never seen a booster so small. It has to be six inches O,D, Some boost is better then no boost.

[Sniper]

Speaking of A bodies, they have an offset booster mount, in it's original application the offset is up, I wonder how hard it would be to rotate that bracket 90 degrees and use the offset to move the booster inboard?

 

https://www.speedwaymotors.com/1965-1970-Mopar-Brake-Booster-Bracket,8901.html

 

 

[nonstop]

4 hours ago, Sniper said:

Was that a 7" single or dual booster?

Mine was a 7 inch dual… It worked, but did not feel like it was providing much boost.  I am also using a Dodge Diplomat master (I think) with a 1 1/32 bore.

[cdnpont]

Completed the master/valving/bracket and associated lines. Still have yet to make a pushrod extension.

Just waiting till July to get to the car then the fun begins.

 

Thanks again to the members and all the good ideas...

 

 

 

 

[diben]

Hey Sam,  what model master cylinder did you use and where did you get the remote reservoir adapters?

[Sam Buchanan]

1 hour ago, diben said:

Hey Sam,  what model master cylinder did you use and where did you get the remote reservoir adapters?

 

Wilwood 1", part #260-7563. The reservoirs come with the cylinder with adapters for either cylinder or remote installation.

[Conn47D24]

These look great !   Mine is working fine,  but looks like a Ham & Egg job compared to these.  

 

Nice work !

[Sam Buchanan]

On 5/8/2023 at 2:37 PM, cdnpont said:

Completed the master/valving/bracket and associated lines. Still have yet to make a pushrod extension.

Just waiting till July to get to the car then the fun begins.

 

Thanks again to the members and all the good ideas...

 

 

Just a datapoint.....the bolts attaching the old master cylinder/pedal support to the bracket are too short. If nyloc nuts are used for locking purposes there should always be at least one, and preferably two or three threads protruding beyond the elastic lock. This is a critical area but something that is easily fixed.

[diben]

Thanks for the information Sam.

[cdnpont]

Update! dual system in, and working well right from the get go. who would have thunk it?

 

 

Time was spent on the initial shoe adjustments, so the brakes pulled straight and true on the road test. The new 10lb residual valves did as expected and kept the shoes out where they need to be. No initial pumping of the pedal like before required.

 

 

I did initially have a concern that the 1 1/8" dual master would have created far too hard of pedal. But not so, the pedal is absolutely perfect and I can fully recommend the size choice. All new Copper Nickle lines, flex lines and wheel cylinders made bleeding the system a breeze. Basically fill the reservoirs, open the bleeders one corner at a time (two on each front, bottom first), wait for fluid to appear at each bleeder. Having the remote reservoirs so high up really helped with gravity. The final pedal bleed was a breeze. Just 3 flair nuts needed a retighten in the system, which is pretty good in my books. We were VERY careful when installing the caps on the master and the drains on the bottles. They are O ring sealed and have a reputation for leaking. A little bit of dielectric grease on the O rings and a careful positioning and tightening of the clamps...no leaks.

 

The master bracket seen in the initial post worked well, although a little trim to the length was required at that forward bolt slot to clear the crossmember.

 

As seen in the image (with a test bolt in place), my diy through rod used the original 7/16 - 24 eyebolt at the pedal end. Had just the right about of back-forth adjustment built in to allow for just a little play at the master before pedal take up. I got lucky with my eyeball engineering!

 

For those who might care, Initially, we hooked up temporary bleed lines from the master outputs up to the fully plumbed in remote reservoirs, to essentially "bench bleed" the master in car. We used two small flared lines at the master, connected by clear tubing up to two little hooked lines at the reservoirs. Again, worked perfect. The air was easy to see and very happy to travel up the line and took maybe 5 minutes of slow pedal pushing to clear. We already had the new front/back lines fitted, removed and pulled to a little to the side close to the master outputs. So it made for a quick changeover from the bleeders to the mainlines. Very little fluid was lost.

 

Yes, we had to move the red firewall build plate more center to fit the reservoirs. The spot chosen was really the best position for them. Purists will cringe at the plate move, but the bottles look pretty good up there we think. Almost factory looking if they ever had done this.

 

The rubber feed lines to new the master "caps" are very close to the floor and crossmember, but fit through just fine.

 

We were able to reset the floorboard panel in place on top of the new feedlines and front brake line, it was tight, but to protect the hoses, we placed a small mat of rubber over them first. We chose to go with sections of hardline in combination with rubber up through this section for durability (and ease of install). The hard lines all have a little bit of a flair hump done on the ends to help with sealing them in the hose.

 

 

Good project, with an appreciable increase in safety! 

Thanks for all the input.

 

 

 

Edited August 10, 2023 by cdnpont
fun

[Saskwatch]

Thank you very much for posting, your progress & all the pictures, nicely done ! 
   ??

[cdnpont]

Thanks! Hopefully it'll give some ideas to others that might be considering something similar.

[Matt Wilson]

On 8/10/2023 at 2:53 PM, cdnpont said:

I did initially have a concern that the 1 1/8" dual master would have created far too hard of pedal. But not so, the pedal is absolutely perfect and I can fully recommend the size choice.

Nice work!  What was the original M/C bore size?  And based on your other commentary, it sounds like you retained the original drum brakes at all four wheels, correct?