Parking brake with T5 transmission conversion

[Theturtle]

My P19 fastback came from prior owner with a T5.  I would have preferred an overdrive equipped car but this was the best P19 fastback I could find locally.  On balance, I like the transmission.  First gear is too "low" but fifth is real great when keeping up with traffic.  Someday I will check into changing to a first gear closer the the stock Plymouth ratio.

 

What I don't like is loss of a parking brake.  I am hoping someone has come up with a solution simpler than swapping in a rear axle that has provision for a parking brake.  

 

Years ago I built two home built airplanes.  A common approach with those was an on/off hydraulic valve.  You would press the brake pedals and then use the valve to hold pressure.  (Handy to temporarily to hold the plane on a slope until you could get wheel chocks.)  I am thinking of something similar that would be operated with the regular parking brake control which is still present on my car.  Has anyone here worked out a good parking brake solution along those lines?  (I am not seeking an emergency brake.  Just something to hold the car temporarily such as when it would stall on a slope.)

[vintage6t]

The "parking brake" on my farm tractor is sort of what you describe. Press in the brake pedal and push down a lever to mechanically hold the pedal down. The tractor brakes are not hydraulic though, just mechanical linkage to the rear wheels.

 

You could do some thing like this. Cable/pulley from your old parking lever to the back of your brake pedal. Pulling the parking lever out pulls the brake pedal down. The parking lever ratchet will hold the brakes on. You would also have to cut power to the brake lights so they would not be on in parking mode.

[kencombs]

The hydraulic solution will work.  But, will not pass inspection in states with that system as the park brake is required to be independent of the service brakes.   Any tiny bypass leak in the master or a leak at any point will result in brake release at some point.   I can do that here as OK has no inspection.   But wouldn't rely on it for anything beyond a few minutes.

 

Parts to do that are available as something similar is use by drag racers to lock front brakes when doing burnouts.  When I messed with that the product was called Line-Loc I think.

 

I know it is not good practice, but I almost never engage the park brake.  I parked my Tundra the other day and wanted to leave it running for a few minutes, so I set the brake and had to look for the release.  It had been that long since last used, I forgot where/how to release it!

 

One solution is a brake on the pinion shaft of the differential.   I have parts of one of those, caliper and disk but will have to fab the brackets as they were only made for Ford 9" as far as I know.   The bracket for that is no where near fitting my Dodge.

 

 

Edited September 3, 2023 by kencombs

[DJ194950]

Kens idea is the best I believe.

 

A replacement rear axle is always a possibility -

 

Other ways for temporary brakes are a available and used for racing , also construction machinery etc.

 

I searched " hydraulic holding brake " and quickly got one response. I did not spend any more time but you sure could.

https://www.jegs.com/p/JEGS/JEGS-Hydraulic-Brake-Lock/1769685/10002/-1

 

DJ

 

 

 

Edited September 3, 2023 by DJ194950
add new rear option

[Young Ed]

Back years ago there was a guy on here that swapped more modern drum brakes onto his stock axle. 

[andyd]

In 1957 Oz Chrysler came out with the Chrysler Royal a 54 Plymouth body with 55 Plymouth fenders grafted on & with 3 different engine & transmission options.....the 230 if you wanted a standard 3 speed, the 250 if you wanted the Overdrive or Powerflite Auto and if ordered with the 313 Poly your only choice was the Powerflite.....

............now the weird thing was that the Overdrive and Powerflite options got you the normal driveshaft mounted Parking Brake setup......no exceptions......

.............BUT if you ordered the standard 230 & 3 speed gearbox you got what I had never seen in a mopar with a sidevalve engine.........you got a rear axle with the Parking Brakes MOUNTED INSIDE the Rear brake drum like late model cars AND the gearbox linkages on the Oz Right Hand Side of the transmission with NO driveshaft handbrake, it was as mentioned inside the rear brake drums

.......so was there any use of a rear axle in USA Mopars with the side valve 6 engines that had the parking brake inside the rear brake drums?...........

.........this pic is of the 1957 Chrysler Royal, unfortunately I never took a pic of the 3 speed gearbox I had with the shifter forks on the US Passenger side.....regards, andyd  

[Theturtle]

Thanks for the comments.  It had not occurred to me to mechanically pull the brake pedal on using the hand brake mechanism.  I am going to see if I can figure out how to do that.   I see the Line-Loc is still for sale.  I have looked a lot at valves on Amazon along the lines of the JEGS item mentioned by DJ.  If the brake pedal does not work out will probably do something using a valve like the JEGS one, but with a lever.

 

On the airplanes I learned that copying someone else's idea works out better than my design attempts.  Hoping I can find something to copy.  If I do it myself, will be sure to post if it is not too ugly.

 

I have learned so much from this forum over the years.  Thanks again to all of you.

[Ivan_B]

6 hours ago, Young Ed said:

Back years ago there was a guy on here that swapped more modern drum brakes onto his stock axle. 

I would also suspect that you do not need to swap the whole axle. Maybe just the back plates and associated hardware? Basically, you only need a pivoted mechanism for pushing the rear shoes apart, which you can control with an existing parking brake cable. If you do planes, maybe it is even possible to adapt something from a more modern vehicle? ?

[Dave72dt]

Line locs, mico locs and hydraulic e brakes like used in drifting and mechanically pulling the brake pedal are still a hydraulic based e-brake and legally only used with a mechanical e-brake.  You need to activate shoes mechanically.   Hydraulics can go away with a pinhole in a line or a weepy cylinder.  Park it on a hill and lose hydraulic pressure and the outcome may not be pleasant.

[YukonJack]

Problem is that parking brakes are also used as emergency brakes. A hydraulic emergency brake is useless if your brakes fail. The T5 conversions have been around for years but if you use the stock rear end you loose the transmission mounted emergency brake. A mixed blessing in my opinion. 

[Sniper]

36 minutes ago, YukonJack said:

Problem is that parking brakes are also used as emergency brakes.

 

Good luck using the stock trans mounted parking brake to stop your car in any manner where the word emergency comes to play.  Eventually? yes, emergency?  no, unless emergency room is what you mean.

 

 

[DJ194950]

Back when horse and buggies ruled the road and cars had to pull to the side of the road when a horse came by.  The E brakes did their job!

 

 Was that an emergency when the name was coined?

 

DJ

[TodFitch]

56 minutes ago, DJ194950 said:

Back when horse and buggies ruled the road and cars had to pull to the side of the road when a horse came by.  The E brakes did their job!

 

 Was that an emergency when the name was coined?

 

DJ

A lot of old literature called it a “hand brake”. And other old literature sometimes called it a “parking brake”. I am not sure when people started calling it an “emergency brake”.

[Theturtle]

I understand that the hydraulic valve method does nothing in the way of an "emergency" brake.  I think a dual master cylinder would go a long way toward this and have been following the recent thread on this.

[Sniper]

A dual master cylinder will do nothing extra in this regard.  There is a reason stock parking brake setups do not use the hydraulics to accomplish this.  That would be because they are not designed for continuous pressure application and a leak anywhere in the system will fail the brakes.

 

You have three choices here.

 

Fab up some sort of pinion mounted parking brake.

 

Swap in a newer style rear axle with brakes that have a parking feature built in, I saw a claim that someone swapped in later brakes on the existing axle.  If that is true that would be an option.

 

No parking brake, park it in gear and chock the wheels.

 

 

[junkers72]

I had adapted backing plates from a 90’s era Jeep Cherokee onto original DeSoto axle . My park brake band was in poor condition so I did use jeep e brake cables and found that I would have to make up a lever to assist with the pull because the hand lever didn’t have enough leverage to properly set the brake to hold on an incline while parked. Was going to move forward with that idea but then scored a very good original brake band and removed all the jeep cables and park brake levers to have a very good functioning original set up . The Jeep drum brakes on the rear are working very well though. 

[Eneto-55]

11 hours ago, junkers72 said:

I had adapted backing plates from a 90’s era Jeep Cherokee onto original DeSoto axle . My park brake band was in poor condition so I did use jeep e brake cables and found that I would have to make up a lever to assist with the pull because the hand lever didn’t have enough leverage to properly set the brake to hold on an incline while parked. Was going to move forward with that idea but then scored a very good original brake band and removed all the jeep cables and park brake levers to have a very good functioning original set up . The Jeep drum brakes on the rear are working very well though. 

What did you need to do to adapt those backing plates?  Also, did you look at doing the same on the front, or do you already have discs up front?

[junkers72]

Scarebird disc on front. Removed seal holder and trimmed excess off to better suit “new” backing plate . Where the spot welds were removed is where I welded it to “new” backing plate. Drilled holes accordingly. Had to message the upper edge of axle housing for it to seat as it should . Shimmed axle end play as per DeSoto shop manual. Had centering lip machined off of original rear hub after removal of DeSoto drum so new drum would go on and seat properly.

[Plymouthy Adams]

I did similar but I also recall that I had to trim a bit for the e-brake spanner to clear the now old seal retainer nut now relocated on the modern backing plate.  There was a number of steps getting the upgrade in place and you will need the tools time and space to work these issues.  It is not just a bolt on as trimming axle mount flange at the top is needed, changing the backing plate bolt patter on two of the 5 bolts, removing and reusing the original seal retainer.    And many do not know the very other step of machining off the step that is a bit wider for the drum to centric align to the original hub.  This can be lead to one or two fixes for the modern drum to fit, either a plate to space out the drum across the full face of the hub or the trimming of the backing plate.  I had two style drums, finned and not finned, the finned sat about .030 deeper at the rear of the drum and would drag on the backing plate just a tad. The inner clearance was sufficient with both drums and not internal drag issues.  I removed about 1/8 inch of the backing plate lip as it had plenty of sacrifical metal to yield to the mod and would not have to mess with aligning an intermediate positioned disc between the hub and the drum.  

Edited September 7, 2023 by Plymouthy Adams

[junkers72]

I agree with Plymouthy Adams, this is not for everyone. I had a co worker who was going through his Jeep Cherokee at the time when I was getting deeper into my project and he loaned me a backing plate to check it out . When I thought It was do able I purchased a few pieces local, used, & affordable and moved forward. Brake shoes, hardware, & wheel cylinders were purchased new after I got it all fitted. Is not a quick, direct bolt on and I used AMC Eagle cast drums to solve the minor depth issue. My original DeSoto rear brake parts were beyond usable and didn’t feel like coughing up the loot for Restoration quality parts.  Hope this helps the OP

[andyd]

I did a somewhat similar but different thing to the Oz Chrysler Royal rear axle/brakes under my 1940 Dodge.   After I adapted 11" vented OZ PBR discs to the front 1941-54 stub axles the rear drums still not great so this is what I did.........this was on a 1962 Oz Chrysler Royal rear end which from what I understood was essentially a 1956 Plymouth rear end..........

.........I removed the rear brake drum and then separated the actual "hub" from the brake drum...

.........I then obtained an Oz 1970 Valiant front disc rotor which was a vented style and had about 1/4" machined from the separated "hub" circumference which allowed it to sit inside the disc rotor then I attached the two together using countersunk 3'8th cap screws.

.........This then allowed the disc to be bolted onto the rear axle via the center nut.

........The remains of the rear brake assembly was removed from the brake backing plate and the backing plate cut down to just a small circular piece that held the seal & bearing as per standard.

........I then obtained 1973 Ford rear Vented Disc calipers and after sitting them against the vented disc rotor was able to come up with a small caliper bracket using 4 of the 5 seal backing plate bolt holes to attach the caliper bracket.

........A small piece of the caliper mount had to be shamfered to gain clearance on the mounting bracket but apart from that the adaption was complete and would still be in use were it not for issues with the rear outer bearing which cracked and spun inside the axle housing gently machining it "oversize"......

.........the first time this happened I had access to a metal spraying company & had the new outer bearing race built up the required 20thou.......the 2nd time this happened after 25 yrs later I did not have the access to this metal spraying process so I replaced the whole rear axle assembly with that from a 1992 Ford Falcon station wagon which virtually bolted in apart from drilling 2 extra U bolt holes....

..........Unfortunately I did not take any pics of what I did but its surprising what can be achieved if you set your mind to it........lol..........Andy Douglas

  

[Theturtle]

In the last day or so I had a note from Russell Nardi of 5speedadapters.com that they are working on a solution.  So I am hoping that works out.  

 

I do not understand the comment above that dual master cylinders would not help.  My impression was that would amount to two independent hydraulic systems.  Loss of fluid from one would leave me with half my normal braking, far better emergency braking that even the OEM set-up.  Still the possibility of a mechanical break in the pedal linkage, but a big improvement it seems to me.

[Eneto-55]

On 9/3/2023 at 11:49 AM, Theturtle said:

....

What I don't like is loss of a parking brake.  I am hoping someone has come up with a solution simpler than swapping in a rear axle that has provision for a parking brake.  

Years ago I built two home built airplanes.  A common approach with those was an on/off hydraulic valve.  You would press the brake pedals and then use the valve to hold pressure.  (Handy to temporarily to hold the plane on a slope until you could get wheel chocks.)  I am thinking of something similar that would be operated with the regular parking brake control which is still present on my car.  Has anyone here worked out a good parking brake solution along those lines?  (I am not seeking an emergency brake.  Just something to hold the car temporarily such as when it would stall on a slope.)

I think I've seen those used on designs for "CycleKarts", but the application, as I understand it, is for short-term parking brake use, not for holding it in place for a duration of hours, or on a hill.  (Most of them are not set up with electric start, so the driver has to be outside the kart to start it, then it can be somewhat difficult to get in, because of the small size of the cockpit.  Many of them are also set up with removable steering wheels, to make it easier to get in and out.)

Edited September 8, 2023 by Eneto-55

[Sniper]

11 hours ago, Theturtle said:

I do not understand the comment above that dual master cylinders would not help.

 

the question was about how to replace the tail shaft mounted mechanical PARKING brake with something else

 

That has ZERO to do with the hydraulics of the SERVICE brake system.

 

You can have no hydraulics at all and the parking brake will be unaffected.

[Eneto-55]

1 hour ago, Sniper said:

 

the question was about how to replace the tail shaft mounted mechanical PARKING brake with something else

 

That has ZERO to do with the hydraulics of the SERVICE brake system.

 

You can have no hydraulics at all and the parking brake will be unaffected.

Have you heard of the hydraulic line lock he mentions? 

[I have never seen one, but have seen descriptions of how they work on another forum.  But they are only intended for very short term holding, and I don't personally think I would want something like that in my brake line on a road vehicle, because maybe it could engage w/o you wanting it to (malfunction), and then your brakes would be on, and no way to disengage them.  But I have never actually seen one, to know if that is even possible.]

Edited September 8, 2023 by Eneto-55