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D400 Wheel cylinders and hardware

Posted: Fri Jul 28, 2017 7:14 am
by Grodr625
Hi everyone, I am working on tidying up my drum brakes on my S400/D400 bus. The rear brake lines I replaced were 1/4" tube 7/16-24 thread. I can only find rear wheel cylinders with 7/16-20 threads. After much searching on this forum, the conclusion I came to is that "Parts are available except for drums and shoes" and that with some measurements and cross referencing potentially some International parts can be adapted.

Anyway, I am on the hunt for all four cylinders and respective brake hardware. Can anyone point me in the right direction? Napa does not list these via light or medium duty databases. Will the 1/2 ton stuff work? I'm assuming I need 1.5" bore, but worried that the thread size on this isn't compatible and would rather not have to run anymore adapters.

http://www.dormanproducts.com/itemdetai ... ame=w28850

Thanks for any and all input.

Re: D400 Wheel cylinders and hardware

Posted: Fri Jul 28, 2017 10:27 am
by Hobcobble

Re: D400 Wheel cylinders and hardware

Posted: Fri Jul 28, 2017 11:05 am
by Grodr625
Hi John, I've checked Rockauto, but was unsure how to correctly source D400 parts since they only list up to a 300 series.

Looks like the D100 cylinders are 1" bore and the D300 cylinders are 1.25" - which matches bore on my MC. Do 300 and 400 series brake parts match?

My confusion is that the dorman part that I linked in my initial post indicates is for a D400 according to application listing and shows 1.5" bore.

Also when checking the D300 cylinders the listings show 7/16-20 threads on all front cylinders except for https://www.rockauto.com/en/moreinfo.ph ... cc=1329421

This shows 7/16-24 for front right, but the corresponding front left shows 7/16-20 threads.
https://www.rockauto.com/en/moreinfo.ph ... cc=1329421

Any further insight? Should I just go for the D300 stuff at 1.25 bore and worry about thread pitch later?

Re: D400 Wheel cylinders and hardware

Posted: Fri Jul 28, 2017 1:32 pm
by dodgeboykim
You might want to try a medium/heavy duty truck parts supplier.

Re: D400 Wheel cylinders and hardware

Posted: Fri Jul 28, 2017 6:06 pm
by PwrWgnDrvr
You can also hone your cylinders and install new cups if they aren't pitted, or have them lined with stainless if they are.

Re: D400 Wheel cylinders and hardware

Posted: Mon Jul 31, 2017 10:25 am
by coelcanth
your project is pretty cool and unique..
but i think you can only do so much research online.
at some point you just need to have the parts in hand.. at least they are not a big investment ! rockauto has one of the D300 dormans on closeout for $3.
i remember my D100 had many different threadings for flare nuts, perhaps it was a system to avoid mixing up parts front / rear / left / right.
the easiest way out might be to bend your own hard lines with custom fittings.

you're probably going to need lots of hard-to-find things for the project over time.
you could find a helpful friendly knowledgable guy at the local NAPA or similar parts counter who will be your ally.
the guys at my shop are not experts in Dodges or anything, but they are always helpful and willing to look stuff up and show me the picture in the computer so i can double check what I'm getting. they'll look things up in the old paper catalogs too by dimensions (like the time i needed an endless drive belt for my southbend lathe or a fuel filter for my single cylinder norwegian diesel) definitely non standard applications !
they have lots in stock too but can get most other things delivered in one or two days. they usually take returns if stuff turns out incorrect.
at the end of the day, they get a kick out of keeping the old equipment running and like to see it drive by.

the truck specialist shops in the industrial areas are probably a good bet for this job too. my local truck brake shop was very helpful when i needed my drums turned, and they were glad to order parts i could not find elsewhere.
have you tried any of these guys in Seattle ? :
-Brake and Clutch Supply, Inc.
-West Seattle Brake Service
-FleetPride

the option to reline and rebuild your original cylinders is good too, especially if the current ones are made in USA and you'll be keeping the truck for a long while.
only thing is the expense.. the shops around here charge somewhere near $75+ per cylinder

good luck !

Re: D400 Wheel cylinders and hardware

Posted: Mon Jul 31, 2017 12:04 pm
by Grodr625
coelcanth wrote:your project is pretty cool and unique..
but i think you can only do so much research online.
at some point you just need to have the parts in hand.. at least they are not a big investment ! rockauto has one of the D300 dormans on closeout for $3.
i remember my D100 had many different threadings for flare nuts, perhaps it was a system to avoid mixing up parts front / rear / left / right.
the easiest way out might be to bend your own hard lines with custom fittings.

you're probably going to need lots of hard-to-find things for the project over time.
you could find a helpful friendly knowledgable guy at the local NAPA or similar parts counter who will be your ally.
the guys at my shop are not experts in Dodges or anything, but they are always helpful and willing to look stuff up and show me the picture in the computer so i can double check what I'm getting. they'll look things up in the old paper catalogs too by dimensions (like the time i needed an endless drive belt for my southbend lathe or a fuel filter for my single cylinder norwegian diesel) definitely non standard applications !
they have lots in stock too but can get most other things delivered in one or two days. they usually take returns if stuff turns out incorrect.
at the end of the day, they get a kick out of keeping the old equipment running and like to see it drive by.

the truck specialist shops in the industrial areas are probably a good bet for this job too. my local truck brake shop was very helpful when i needed my drums turned, and they were glad to order parts i could not find elsewhere.
have you tried any of these guys in Seattle ? :
-Brake and Clutch Supply, Inc.
-West Seattle Brake Service
-FleetPride

the option to reline and rebuild your original cylinders is good too, especially if the current ones are made in USA and you'll be keeping the truck for a long while.
only thing is the expense.. the shops around here charge somewhere near $75+ per cylinder

good luck !
You make a good point, but I'm certain that somewhere in Internet land is a parts breakdown with Chrysler part #s for a factory brake setup on a D400. This is what I was hoping for, but will take advice given here and break it apart in hopes of matching casting #s to a good part #.

I have been to Seattle Brake and clutch and will likely have them reline shoe steel, if needed. Will be checking with Fleet Pride as well! Best case scenario- we replace 4 cylinders and hardware and adjust shoes. Fingers crossed

Re: D400 Wheel cylinders and hardware

Posted: Mon Jul 31, 2017 12:22 pm
by soopernaut
Did you look through any of this?

http://sweptline.org/brakeservice63_68/index.html

Re: D400 Wheel cylinders and hardware

Posted: Tue Aug 01, 2017 5:03 pm
by coelcanth
i can see you have a tough project ahead of you ..
there is almost no mention of the 400 series in the literature !

Re: D400 Wheel cylinders and hardware

Posted: Wed Aug 09, 2017 9:08 am
by Grodr625
soopernaut wrote:Did you look through any of this?

http://sweptline.org/brakeservice63_68/index.html

This is excellent! Are you able to cross to part #s based on the numbers given here? Is there an accompanying index, or are these to be understood as Oem Mopar part numbers? I see the rear brake diagram, but not the front, are they identical? Was trying to find a part # on the wheel cylinders, but my amateur sleuthing came up empty handed.

Thanks again!

Re: D400 Wheel cylinders and hardware

Posted: Wed Aug 09, 2017 9:11 am
by Grodr625
coelcanth wrote:i can see you have a tough project ahead of you ..
there is almost no mention of the 400 series in the literature !
Even then VIN decoder here conveniently leaves out the S400! The shop manual has not been as useful as I had wished. But she runs and drives now and is stopping on three drums with my leaky cylinder plugged at the tee on the rear axle. This has renewed steam going into the project considerably :)

Re: D400 Wheel cylinders and hardware

Posted: Wed Aug 09, 2017 9:58 am
by PwrWgnDrvr
For the most part, the S400 is identical to a D400. Basically, its a D400 with a school bus body on it.

Re: D400 Wheel cylinders and hardware

Posted: Wed Aug 09, 2017 10:51 am
by soopernaut
Grodr625 wrote:
soopernaut wrote:Did you look through any of this?

http://sweptline.org/brakeservice63_68/index.html

This is excellent! Are you able to cross to part #s based on the numbers given here? Is there an accompanying index, or are these to be understood as Oem Mopar part numbers? I see the rear brake diagram, but not the front, are they identical? Was trying to find a part # on the wheel cylinders, but my amateur sleuthing came up empty handed.

Thanks again!
Take the number given in the drawings and go to the page with that number before the part description. Then go down the 1st column until you find "D" or "S" and the column marked 400 will have a 1 or 2 (amount) or more if needed. The last column on this line is the part number.

Re: D400 Wheel cylinders and hardware

Posted: Thu Sep 28, 2017 1:00 pm
by Grodr625
So I finally got the rear drums off and luckily there's plenty of meat left and they are being cut by a heavy truck shop in town. My next puzzle is finding the correct wheel cylinders. The casting #s on the ones installed are a little difficult to make out. They read "BENDIX 9743" I THINK! This 9743 crosses over to a wheel cylinder that does not match what I have.

Per the Dodge parts listing it should require part # 2084-408 which does indeed look like what I have mounted, problem is the thread pitch is off. 7/16-24 from my brake line to 3/8-24 into these Napa wheel cylinders https://www.napaonline.com/en/p/UBP27342

The parts listing also shows #2084-406 for the front brakes which crosses to a rear wheel cylinder with thread inlet size of 7/16-20, closer! Will 7/16-20 and 7/16-24 play well enough to thread without damage or leaks? **Its possible the 1/4" tube line that I replaced, but haven't run pressure through, was the wrong thread pitch! ** Yikes
https://www.napaonline.com/en/p/UBP28850

Am I decoding my casting # incorrectly? The above links are what it should look like, but the advertised fitting size is wrong. Should I keep digging for the right stuff or consider running adapters to each port?

https://i.imgur.com/a2EHS8t.jpg

https://i.imgur.com/3qvqI9K.jpg

https://i.imgur.com/Y0SeQmb.jpg

Re: D400 Wheel cylinders and hardware

Posted: Wed Nov 01, 2017 1:00 pm
by moparbay
I know this will not help much but on my 67 D400, the front and rear wheel cylinders are absolutely different. The front only has 1 wheel cylinder per side (assuming it is a double piston)and the rear has 2 wheel cylinders per side (assuming single piston). I am in the process pulling the rear hubs off mine to see what they are.

Re: D400 Wheel cylinders and hardware

Posted: Wed Nov 01, 2017 1:52 pm
by dodgeboykim
Personally I would source the correct line fittings to fit wheel cylinders to make up lines from bulk line. When I redid the brake system in my 70 D500 every line was hand fabricated and bend by me for a nice fit. Only thing bought pre made were the hoses. :thinking

Re: D400 Wheel cylinders and hardware

Posted: Sat Nov 25, 2017 10:19 am
by Kaegi
did you ask seattle brake and clutch if they shows WC part numbers?