brake job scaled back

[DonaldSmith]

My 47 Desoto Suburban pulls to the left, after having been in slumber for a month or so.  After a mile or so of hard stops, the pulling goes away.  Last Fall, from highway speeds, I stopped late for a yellow light, and ended up a few car lengths farther than I wished.  And is the pedal travel getting to be bit much?  Next July we are going to the National DeSoto Club convention, in Chatham, Ontario.   Ooh, ooh, cross the border.  (Easier than it had been.)  Anyway, the car is running well, but what about the brakes? 

 

Immediate jump-to-conclusion - disc brakes in the front.  I even sent a message to James Douglas, to see how his Suburban Brake project is coming.  Then i looked up his posts - Custom Fabrication.  Lathe.  Wheel Hell.   I had fallen into the old car trap.   A slight problem calls for radical solutions.  "My starter won't crank - I need 12 volts."  "The rear seal is leaking - I need a V-8."

 

Cooler thinking - these brakes were good for their time.  I've driven the car for 20 years, carefully, not following too close, and the brakes performed well.  And Chatham is only an hour and a half from us, and I've gone that far before.  

 

Before ripping out the system, pop the drums and inspect what I have   Proceed methodically.   Follow the Shop Manual.  (The Brakes chapter doesn't tell how to get the drums off, but  the Forum has discussed front wheel nut tightening and cotter pinning, and rear wheel mega-puller pop-off.)   I think I see the path before me.    

 

James Douglas, how's it going with the disc brake project?  Just curious.  No rush. 

[oldodge41]

"The old car trap" been there, done that! I like the way you're thinking.

[LeRoy]

In top condition 47 brakes will lock up the tires. Put it back original and ensure everything is like new and I think you're good to go. 

[RobertKB]

7 minutes ago, LeRoy said:

In top condition 47 brakes will lock up the tires. Put it back original and ensure everything is like new and I think you're good to go. 

I agree. I had to stop very suddenly in my ‘51 when a semi turned in front of me. Locked up tires and they squawked. Avoid “the old car trap” and go with your plan. Sounds like you might have a slight safety issue you need to deal with. Good luck!

[Los_Control]

2 hours ago, DonaldSmith said:

I've driven the car for 20 years, carefully,

 

2 hours ago, DonaldSmith said:

(The Brakes chapter doesn't tell how to get the drums off, but  the Forum has discussed front wheel nut tightening and cotter pinning, and rear wheel mega-puller pop-off.)   I think I see the path before me.    

 

 

I think @LeRoy is correct. ..... I also think you may be slightly overdue for brake maintenance    

 

Possible all you need is a good adjustment to get them back into good working condition.

If your drums are worn beyond safety specs, then I might start considering disk brakes or other avenues.

[Sniper]

9 minutes ago, LeRoy said:

In top condition 47 brakes will lock up the tires. Put it back original and ensure everything is like new and I think you're good to go. 

 

Just don't ride your brakes down a mountain.

[desoto1939]

Don Smith: My brakes did pull on my 39 Desoto. Tried everything, no leaking or anything could be found. I took my front drums and had both turned down a little. seems as if I had a high spot on one and this was causing a pulling. Before you turn them down take the lug nuts or bolts with you. Since we have riveted hub and drum you need to make sure the drum and the hub are tight. This will make sure that the cut is straight.  My mechanic told me this has to be done in insure a straight cut.

 

Good luck at the NDC meet in Chatham.  I attend the meet in Altoona the past June and received a 3rd place on my 39 Desoto.  We had three 39's and all placed 1st,2,bd, and 3rd.  We will not be attending the NDC convention in 2023.

 

Rich Hartung

desoto1939@aol.com

[LeRoy]

On 12/17/2022 at 9:44 AM, Sniper said:

 

Just don't ride your brakes down a mountain.

is that experience talking?

[Sniper]

15 hours ago, LeRoy said:

is that experience talking?

Not in the 51, but in other all drum cars, like my 64 300

[busycoupe]

On 12/17/2022 at 9:44 AM, Sniper said:

 

Just don't ride your brakes down a mountain.

In the fall my wife and I took a leaf peeping ride around the local ski mountain.  Coming around the backside of the we came down a rather steep half mile long twisty slope.  Near the bottom there were a bunch of cars parked near a rail head.  After riding the brakes down the hill it was all I could do to stop before hitting them ... standing on the brake pedal, downshifting, usung the parking brake.  We stopped in time, but it was un-nerving.   I am going to inspect the brakes before spring, but I think it was just brake fade.

[Sniper]

Scary, isn't it?  I no longer live anywhere near mountains but the memory lingers, lol.

[48ply1stcar]

Are your brakes the same as the P15, with a cylinder per shoe.  if so and you want to enjoy the ride go disc.

I went with a scarebird kit, although I se they don't include the hubs.  get a kit with hubs and you'll never regret it.  My mother bought me my car for $75 in 1968 and I stalled the disc in the spring of 2020.  I'm still using the stock master cylinder without the residual valve.  eventually I'll put a residual valve front and back 2 and 10 pound.

 

 

[keithb7]

Never going down a hill faster than I can travel up it in my flathead equipped old car, is a fair guideline. Indeed you have a limited number of controlled braking applications while descending a long steep hill. After 2 possible brake applications to control my speed, for me the third time is usually a hard brake. Knocking me down to 25 mph. Then I can comfortably grab 2nd gear and ride it all the way down.  I can’t say I’m not always looking for safe escape paths in the event of a brake failure.  I’m not paranoid, just being realistic. My brakes are stock, well maintained and work well. Yet suddenly its 1938 when I’m behind the wheel.  

[LeRoy]

51 minutes ago, keithb7 said:

Never going down a hill faster than I can travel up it in my flathead equipped old car, is a fair guideline. Indeed you have a limited number of controlled braking applications while descending a long steep hill. After 2 possible brake applications to control my speed, for me the third time is usually a hard brake. Knocking me down to 25 mph. Then I can comfortably grab 2nd gear and ride it all the way down.  I can’t say I’m not always looking for safe escape paths in the event of a brake failure.  I’m not paranoid, just being realistic. My brakes are stock, well maintained and work well. Yet suddenly its 1938 when I’m behind the wheel.  

I was engine braking recently and it kept jumping out of 2nd gear. I don't know if it's linkage trouble or trans. It would stay in 3rd or 1st without fail. I ended up just going into 1st and creeping down.

[keithb7]

Clutch gear (synchro) on second gear is well worn. Will pop out of gear if going downhill while holding back your vehicle. 

Edited December 21, 2022 by keithb7

[MarcDeSoto]

Just watch Bogart in High Sierra if you want a lesson in how to drive a 38 Plymouth in the Sierra Nevada mountains with the cops after you!  

[Los_Control]

Was a common trick the old dirt track racers would use. Create a wire loop or hook on the dash board, when they get in 2nd gear they used it to hold the shift lever in 2nd gear.

The short small dirt tracks 2nd gear was the main gear .... wind the piss out of it going down the straight away then back off the throttle going into the corner .... they just stayed in 2nd gear. Was tough on the syncros  & always pop out of gear when backing off the throttle.