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Correct front wheel cylinders for 10" drum brake A-Body?

Posted By: vinnyd76

Correct front wheel cylinders for 10" drum brake A-Body? - 01/16/19 06:22 PM

Having some issues locating the correct front wheel cylinders for 10” drum brakes on a 70 Duster.

Background:
I ordered a set of front wheel cylinders from my local auto parts store and I received a set of Raybestos (part numbers: 37171 and 37172), which are not correct. These numbers were confirmed by Raybestos this morning, but appear to be for a B or E-Body. These part numbers were called out for both 10” and 11” Drums in their system, which appears to be incorrect for an A-Body? Below is a pic of the wheel cylinder that I’m being told is correct for a 10” drum application and I also included the small brake line that attaches between the wheel cylinder and flex line for reference.

Anyone have a similar issue and/or can point me in the right direction? Below is what I had the tech at Raybestos look up and provide info.

1965 – 1967 Barracuda: Part Number 36050 and 36051
1968 – 1969 Barracuda: Part Number 37102 and 37103
1970 – 1972 Duster Part Number 37171 and 37172

The bore sizes on these Raybestos wheel cylinders bore size appear to be common at 1”, but the thread for the LH is 7/16” 20 and RH is 3/8” 24.

I'm open to other brands... thank you in advance for the help!!

Attached picture Wheel Cylinder Example.JPG
Attached picture 70 Duster Wheel Cylinder to Flex Brake Line.JPG
Posted By: mopars4ever

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/16/19 07:21 PM

70 A and B E body 10 inch front are the same part numbers 3420995 and 3420996 L&R. https://www.ebay.com/itm/NOS-MoPar-1969-...96/272672957491
Posted By: vinnyd76

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/16/19 08:46 PM

I'm told it should be a 3/8" 24 thread to accept a 3/16" brake line. The bottom hole should be an inverted flare. Thoughts?
Posted By: RapidRobert

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/16/19 09:08 PM

^^^ first sentence is correct. not sure if the other is or is not. EDIT looking at the bottom one closer it appears to the same double flare but there is the smooth extension of the male fitting. I would see what the inside threaded area on the old wheel cyls looks like.
Posted By: charge70

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/17/19 03:36 AM

All 10" A-body flex hoses screw directly into the wheel cylinder.Only 9" A-body brakes use that small steel line between the hose and the cylinder.Also the pic of the wheel cylinders you posted shows the bleeder straight out,all 10" brakes I've seen have the bleeder coming out at an angle to clear the spindle.Something not right here
Posted By: Supercuda

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/17/19 03:58 AM

Those are not 10" drum wheel cylinders.

Get a copy of the FSM, in the brake section it is clearly shown. http://www.mymopar.com/index.php?pid=109

The Raybestos ones match the FSM. You either do not have 10" front drums or someone put wheel cylinders out of a 9" drum in there.
Posted By: vinnyd76

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/17/19 05:10 AM

Originally Posted By Supercuda
Those are not 10" drum wheel cylinders.

Get a copy of the FSM, in the brake section it is clearly shown. http://www.mymopar.com/index.php?pid=109

The Raybestos ones match the FSM. You either do not have 10" front drums or someone put wheel cylinders out of a 9" drum in there.



Thank you very much for the service manual link!

One key point that I read in both the Dart and Duster manuals is the following snip. Does that not reference this small jumper line?

Attached picture Service Manual - Brake 2 of 2.JPG
Attached picture 70 Duster Wheel Cylinder to Flex Brake Line.JPG
Posted By: Supercuda

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/17/19 04:01 PM

9" drum ONLY

If you have that you have 9" drum parts
Posted By: vinnyd76

Re: Correct front wheel cylinders for 10" drum brake A-Body? - 01/17/19 04:35 PM

Originally Posted By Supercuda
9" drum ONLY

If you have that you have 9" drum parts


Take a look at this file that I received this morning.


It appears all these new wheel cylinders today require a bubble flare and double flare for the steel line to attach to the wheel cylinder and the rubber brake hose (reference above).

Attached picture Assembly Instruction.JPG
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