Brake problems on my Ply 46 Coupe

[Forty6217]

Hi

I have been working on my coupe front brakes now for about a week, trying to work out what is wrong and why I cannot adjust them.

The drum is 10.000 in internal diameter

The linings are 13/64" or 5.3mm which appears to be an oversize.

However when I set it up for the heel of the lining to touch the drum with the cam it does not seem to be connecting correctly and its as if the piston is to far out of the wheel cylinder. I have set it up like this and while I have been driving i have applied the brake heavily and the rubber seal blows out and I loose all brakes, lucky the park brake is pretty good and there was nothing in front of me at the time.

I have tried to understand why, are the pins the push the brake linings out to short? are they from a different model car? they measure from the end that goes into the piston to the part that contacts the shoe 3/4". (not the guide fingers)

I have thought about increasing the lining thickness to 0.289" or 7.3mm, this may change the point of contact which may have a non working surface effect, dont know? I have lined up the brake shoe inside the drums and the current point of contact looks fine.

I am a bit stuck, can anyone shed light on my situation.

Thanks Mike

Edited May 2, 2011 by Forty6217
Heading is not discriptive enough

[Dodgeb4ya]

You will need to check your wheel cylinder piston and push rod combinations. Here are some pics of the different types. Your push rod you are using must be the shorter one.

Bob

[Forty6217]

Thanks Bob

I did not know that there were 3 different types and sizes of pins.

Do you know which of these pins suits which era which model and which year.

Are they "case" hardened or all hardened steel?

Can you give me the size of the one in the middle. from were it sits in the piston to were it seats on the brake shoe

Thankyou very much, i was pulling my hair out, now i can get on my lathe and make 4 pins the correct size.

Cheers Mike

[Dodgeb4ya]

Here are pics with caliper readings. The pins are hardened steel. Only 2 sizes of push rods-long and short. Don't know why I showed the middle push rod-it is just a different style with a small hole through it to pin it to the shoe-obsolete. These were old pic's of a previous posting I did way back.

You will need to use the longer push rod to keep the pistons from extending too far.

Bob

[Forty6217]

Bob

That explained it all.

Thanks for your help.

Mike

[Forty6217]

Hi Bob

A friend of mine was over from the US and in Australia just recently and he brought me over a set of the longer push rods and have I have installed them and now I feel a lot more confident with my braking system. cheers Mike

[Plymouthy Adams]

this just came up locally and after talking and hashing out some of the things in the work over the phone..it was concluded that some of the newer piston/pins coming across the counter are being mixed and matched and thus you may not get the right combo..there are a few different lengths I understand..the push pins are of a different base size for the piston also..so the local fix involved cutting the rod slot to allow proper fit and adjustment...of course the use of the AAmco 1750 is very beneficial here

[zephyrland]

Time to wake up an old topic.

 

I am doing a brake job on my 1947 Dodge Custom Coupe.  I have the red cyllinders and the push pin things are attached to my brake shoes.  At least I think they are. (there seems to be small rivet holes on each one) I haven't just smashed them off with a hammer, nor have I drilled them out,  as I don't want to damage the existing shoes I have(despite them basically being bare metal)

 

Question:

 

Can I drill them off of the old shoes and then attach them to the new shoes without some sort of mounting hardware?  Will the shoe springs keep them in place? Or am I missing something obvious?

 

Help

[P15-D24]

Push pins are normally not attached to the shoe. The springs hold them in place. 

[Dodgeb4ya]

This is the type of pin retained pin he is talking about. I had these on my 46 NY business coupe.  They are kinda a hassle to remove. Gotta punch the little pin out to remove the W/cyl push rod.

[zephyrland]

Think I can reuse the pin/rivet?

[Dodgeb4ya]

You don't really need to as they discontinued that style push rod and liitle pin. I think in 47. Knock the little pin out and reinsatll the wheel cylinder push rod prperly connected to the brake shoe indent when reassembling the brakes

[zephyrland]

You don't really need to as they discontinued that style push rod and liitle pin. I think in 47. Knock the little pin out and reinsatll the wheel cylinder push rod prperly connected to the brake shoe indent when reassembling the brakes

Cool!  When I pop the fronts off again, I'll put the new shoes on.  new (old)shoes, yay!