Non stock rear brake repair on a P15

[BobT-47P15]

Way back when....before I met it....the driver of my future 1947 Plymouth P15 evidently ran off the road and into a ditch, over a culvert or big rocks, or some similar mishap. 

There are some big scratches on the frame......both front and rear passenger side fenders were replaced, body work was done on the passenger door and quarter.......and

the rear axle/differential was replaced by what was presumably available at their local salvage yard that would fit.  The best guess made so far by a parts vendor is perhaps

a rear end from a 1939 Dodge pickup.    Actually certain parts seem to apply from 1939 up to 1948 or so.  

 

So, a few days ago I stepped on the brake pedal and it went to the floor.  A check of the inside of the tires indicated the left rear wheel cylinder was leaking.

We removed the wheels and brake drums to inspect.  Turns out that due to old age, it's time for new brake shoes.....as well as a pair of new wheel cylinders.

The cylinders are larger on one half than the other......one end is 1" diameter, the other end is 1 1/8" diameter.  And the tabs on the brake shoes that go into the

ends of the wheel cyls are larger/longer than a P15.  Found an area auto supply who can send my shoes to Kansas City for re-lining at about $15 per shoe.  I have

two n.o.s. (or at least kinda old) wheel cylinders that may still be usable.  If not. will get some more.  AB says he carries 3 varieties similar to mine and one should

probably work.  Will have to send him one foe a sample if I order.   Or.......can send the cyls to White Post Restoration shop who will bore them and install stainless sleeves'

My cyl might cost $175 each due to their style....otherwise about $87 each.   Then I have just received an inner and outer grease seal for the right rear axle

which has been leaking some grease.  Fun stuff.   I am getting to try out my new 3 1/2 ton floor jack received for Father's Day for the first time.  So far, so good.

 

The wheel cyl and shoes this rear end uses.

 

 

Presumed 1939 Dodge PU rear.....?

 

Grease leak on R R.

 

The car when I got it 1973.

 

Edited September 11, 2019 by BobT-47P15

[keithb7]

I find it interesting that you have different sized wheel cylinders. I can understand how that may have happened. I am wondering what that does to effect braking? Unequal hydraulic pressure at the cylinders? Perhaps different travel distances too. Which is likely a clue why you have 2 shoes with longer tabs on them, where they contact the cylinder. Have you had a look at the master cylinder to determine its diameter? Up to this point how did it feel when braking?

Edited September 11, 2019 by keithb7

[greg g]

I think those stepped wheel cylinders were mentioned as being used on 40/ 41.  But my recollection is that they were on the front brakes of those cars.  Did the 40 or 41 have Plymouth have single front wheel cylinders instead of the dual  46 on set up?

[greg g]

There are some pics and info in this old thread thar might help.  I think those stepped wheel cylinders were mentioned as being used on 40/ 41.  But my recollection is that they were on the front brakes of those cars.  Did the 40 or 41 have Plymouth have single front wheel cylinders instead of the dual  46 on set up? Maybe less expensive to do a more modern rear axle with better parts availability.  Might be less money also.  Ford ranger, Jeep non grande Cherokee, early Dakota.

 

 

Edited September 11, 2019 by greg g

[BobT-47P15]

My car has the correct, original style two cylinder front brakes.  Have never studied on the master cylinder.  (I do have a new one still wrapped

up from my trip to Carlisle 3 or so years ago.)  The brakes have always worked fairly well....considering it's an old system.  But not as well as

an updated system with discs, etc, of course. 

 

When you install disc brakes on the front of a P15.....can you use the original wheels or do you need to update to a newer, deeper style?

I want to be able to use my 1955 Chrysler wire wheels.

[greg g]

Depends on kit and the pieces used.

[Merle Coggins]

The B-series 1/2 and 3/4 ton trucks used stepped bore wheel cylinders on the front and dual cylinders in the rear (similar to the fronts on the cars). I wonder if the T, and W-series trucks used the stepped bore cylinders on the front and rear. If this is indeed a '39 truck axle that may indeed be the answer. Maybe one of the earlier series truck guys can chime in on this... 

I don't believe anyone makes the step bore cylinders anymore, but places like Whitepost or Hagens(?) can sleeve them and revive them.

[Jerry Roberts]

Here is a photo from the shop manual for 1938 Dodge truck , the 1939 Dodge truck used the same manual but there was a thin supplement book used too . The photo is for the RC model ( 1/2 ton )  and the RD model ( 1 ton ) trucks . The photo looks the same as your photo . Also the manual shows the stepped wheel cylinders with the small piston for the front and the large piston to the rear . If you should decide to order parts for a 1939 Dodge truck , 1/2 ton , that would be model TC  .

Edited September 12, 2019 by Jerry Roberts

[9 foot box]

   The W-Series Dodge truck's use a Raybestos WC6353 cylinder, left front or rear, WC6354, right front or rear. The body is 3.750" wide, without caps, 1.750" bolt pattern. It has a larger step bore than your measurements, but it might work. 

[Bobb Horn]

My 38 Coupe has wheel cylinders that are larger on one side,  like 1 3/8 to 1 1/4 on the front, and on the rear 1 1/4 to 1 1/8.

The shoe lining are of different lengths also from one side to another.    I think it is all about balance of lining pressure....

I installed Ford Granada shoe linings of the same length.     One side may wear quicker than the other, but they work good.....

[Frank Elder]

Wouldn't a truck axle have the spring perches on top of the axle for carrying a heavy load as opposed to the perches in your photo which are mounted below the axle?

[BobT-47P15]

Good question Frank.  I do not know the answer.  

 

Jerry Roberts........in your pickup book......where is the spring perch, above or below the axle?

The picture you posted does look like mine.

 

What I am going by is this--- several years ago I had to replace the brake cylinders and Mr Andy Bernbaum from whom I bought

those cylinders remarked they were probably from a 39 Dodge pickup due to their style.  I had to send him an old cylinder so

he could match it from his stock. 

Otherwise, I don't know what this axle came from......apparently something they found in a

junkyard in the late 1950s or sometime in the 1960s that they felt would fit the car.

 

Thanks to everyone for information .... I'm apparently never too old to learn.       

Edited September 13, 2019 by BobT-47P15

[Jerry Roberts]

1 hour ago, BobT-47P15 said:

Jerry Roberts........in your pickup book......where is the spring perch, above or below the axle?

The spring perch is above the axle . 

[BobT-47P15]

Interesting.    Thanks.              1941 Plymouth truck

[BobT-47P15]

Well then.....if the perches of pickups and other trucks are above the axle (which I didn't know til now)  (Thanks Frank).......then my rear axle must have

come from a car in the 1938 to somewhere in the 1940s era......probably Dodge or Plymouth.        I definitely have the step wheel cylinder with the two

different size halves.     Appreciate the input.   

[Merle Coggins]

Look closely to see if there are any signs that the spring perches were cut off and re-welded on the bottom. 

[BobT-47P15]

Hi Merle,  I looked and can not see any evidence of welding. 

[plymjim]

  Recently replaced the wheel cyls. on my '38 Dodge D-8. Just went to the garage

& measured the old ones. For  the rear the mounting bolts are 1 3/4" center to center.

Stepped bores measure 1 1/4" and 1 3/8".  

  Got replacements from Andy B.