15/16" Brake Master Cylinder

hansken_yo · Post by **hansken_yo** » Thu Dec 04, 2008 2:48 pm

Napa Autos has a special order Brake Master Cylinder for non-ABS 4 wheel Disc Brake Neons 2000-2005

Part Number is 390638

This is a great upgrade for those doing brake swaps and upgrades to big brake kits.

Others have shown up through different locations and stores I'll list those as well

Graphite SRT wrote:you can just get it from rockauto.com

listed under 02 Dodge Neon ES

RAYBESTOS Part # MC390638 {Professional Grade Bore Size=15/16" Number of Ports=3 Secondary Outlet Size=M18x1.0/7/16-24}
Front Disc Brakes; Rear Disc Brakes; Power Brakes; Non ABS Brakes; 15/16" Bore

Ntyvirus1 · Post by **Ntyvirus1** » Thu Dec 04, 2008 3:20 pm

would a normal srt master cylinder work?

hansken_yo · Post by **hansken_yo** » Thu Dec 04, 2008 4:05 pm

No, because the SRT MC has only two ports which leads to the ABS controller that then leads out to the 4 brake lines.

This MC still has the same 4 ports that an SXT, ES, SE whatever has, but with the larger bore to accommodate the 4 wheel disc brakes which takes a little more than drum.

Ntyvirus1 · Post by **Ntyvirus1** » Thu Dec 04, 2008 6:17 pm

looks like i need to get more money together

hansken_yo · Post by **hansken_yo** » Thu Dec 04, 2008 11:34 pm

The stock 7/8" bore is sufficient for a straight SRT rear disc brake swap. However, for a full SRT swap it is my opinion that the 7/8" bore is lacking and even more so with a big brake kit.

Caraudioholic24 · Post by **Caraudioholic24** » Sat Jan 02, 2010 10:02 pm

When you say sufficient do you mean it will run ok?? I don't mind spending the money if I know the 15/16 one will work a lot better. Im only doing the srt-4 rear setup on my 05 for now and possibly doing stainless steel brake lines. Thanks

hansken_yo · Post by **hansken_yo** » Sat Jan 02, 2010 11:31 pm

You'll be fine if your just doing the rear. You will still get a stiff pedal without worries.

It is when you upgrade to the whole front/rear SRT brakes that the pedal starts to get squishy. and then a little more so with the BBK.

Caraudioholic24 · Post by **Caraudioholic24** » Sat Jan 02, 2010 11:40 pm

Ok I just dont want to have to rip apart the brake system because of a shitty pedal feel. I wanna do it right the first time even if that means buying the MC. I have a frined at a couple of parts stores.

The stainless steel lines should help also right?? Now I guess the right way would be to buy two sets. LOL the srt set just for the rear lines and the neon set for the front lines. WTF!! Maybe I can sell the ones Im not gonna use!!! Thanks for the quick reply!!

srtgtr34 · Post by **srtgtr34** » Sun Jan 03, 2010 12:02 am

Caraudioholic24 wrote:Ok I just dont want to have to rip apart the brake system because of a shitty pedal feel. I wanna do it right the first time even if that means buying the MC. I have a frined at a couple of parts stores.

The stainless steel lines should help also right?? Now I guess the right way would be to buy two sets. LOL the srt set just for the rear lines and the neon set for the front lines. WTF!! Maybe I can sell the ones Im not gonna use!!! Thanks for the quick reply!!

You really don't need SS brake lines, unless your going for looks.
I just hooked up my rear discs and with them being bled well with all new fluid, the pedal is very stiff, at least twice as stiff as with the drums. SS lines would probly be overkill, unless of course you just want the bling factor.

Caraudioholic24 · Post by **Caraudioholic24** » Sun Jan 03, 2010 12:11 am

Yea its kind of just that LOL I picked up a nice set of cross drilled and slotted rotors and figured those would help set everything off. Just sux that to do it right I have to buy two kits. Why dont they sell fronts and rears. LOL

hansken_yo · Post by **hansken_yo** » Sun Jan 03, 2010 12:31 am

SS brake lines won't stretch compared to regular brake lines during high stress braking (such as tracking the car) though I hear it is minimal.

Caraudioholic24 · Post by **Caraudioholic24** » Sun Jan 03, 2010 1:14 am

so thats good right. no expansion more pressure so nice and strong pedal feel right. thats what i want.

hansken_yo · Post by **hansken_yo** » Sun Jan 03, 2010 1:18 am

Essentially.. yeah.

Post by **occasional demons** » Sun Jan 03, 2010 9:13 pm

The only claim I have seen is the response time is a little faster due to the lines not swelling as much during braking. How much difference it actually makes, IDK.

Caraudioholic24 · Post by **Caraudioholic24** » Sun Jan 03, 2010 9:30 pm

Yea that makes sense Bill. Thats what I figure will make up for changing out the master. Thanks for all the help everyone. Im savin up to buy 2 different sets of lines if anyone is interested in the ones Im not gonna use!!!

NickKo · Post by **NickKo** » Sat Jan 09, 2010 9:53 pm

occasional demons wrote:The only claim I have seen is the response time is a little faster due to the lines not swelling as much during braking. How much difference it actually makes, IDK.

"Depends".

On my old '71 Ply.Scamp, I completely rebuilt the entire braking system.
After 150,000+ miles and 25 YEARS of use, the original lines were getting cruddy inside and out, and the flexible rubber lines were starting to get too flexible.

I replaced the Master Cylinder, rebuilt the proportioning valve, and upgraded to Stainless Steel hardlines, AND also to SS flex hoses (to replace the rubber hose.)
WOW, what a difference ! I could actually modulate the brakes afterward.... plus it made braking much easier.

The moral of the story:
If your rubber / flex lines are getting old and / or have high mileage, then upgrading to SS flex lines may make a noticable difference..... if only because the old ones needed replacing anyway.

- Nick

excon · Post by **excon** » Tue Jan 12, 2010 5:49 pm

again, you don't need two sets. Just saying it again so you don't have to waste another $100.

p.s. read the sticky.

viewtopic.php?t=12341

hansken_yo · Post by **hansken_yo** » Tue Jan 12, 2010 5:55 pm

Not to be an ass, but can we keep this thread related to the master cylinder please.

and Thanks excon for posting a link for the SS brake line discussion.

Caraudioholic24 · Post by **Caraudioholic24** » Tue Jan 12, 2010 6:19 pm

excon wrote:again, you don't need two sets. Just saying it again so you don't have to waste another $100.

p.s. read the sticky.

viewtopic.php?t=12341

yea i read it but didnt know if anyone had any problems with them loosening up. i figured i would start that thread. thanks for the heads up.

thats the last i will post on here about them.lol

ragek23 · Post by **ragek23** » Tue Jan 12, 2010 7:54 pm

in that case I have a full set of ss brake lines laying around for any 2nd gen w/drums

.

front srts and rear drums.

Post by **occasional demons** » Fri Jan 29, 2010 1:00 pm

For reference: NAPA pn# UP 390638

hansken_yo · Post by **hansken_yo** » Fri Jan 29, 2010 2:23 pm

occasional demons wrote:For reference: NAPA pn# UP 390638

That is correct and posted in the first post
Thanks

Post by **Canada** » Mon Feb 28, 2011 7:51 pm

As a quick update, this is on sale for $50 CDN at Rock Auto right now if anyone wants one cheaply...

hansken_yo · Post by **hansken_yo** » Mon Feb 28, 2011 8:08 pm

That is a steal!!!!