Actually considering how bad that piston is I'd probably just cut it off..
1968 Plymouth GTX
- Thread starter '68 Coronet R/T
- Start date
'68 Coronet R/T
Well-Known Member
I think that is a great idea.
'68 Coronet R/T
Well-Known Member
No, I go the one listed for my B-body.
Plan on sending it back... First, your running discs in the front, that's a four wheel drum M/C.... Second you'll want no bigger than a 1 1/16th bore, preferably a 1" bore...
If your not running a booster you'll need a smaller bore M/C to try to compensate... You wind up trading pedal travel for pedal feel...
Might even drop down to a 15/16" M/C like this one..
Mopar 15/16 bore master cylinder A B E body Cuda Charger 4 bolt cast iron | eBay
This is a new in the box cast iron master cylinder for Chrysler disc brakes 1 /2 -20 and 9/16 -20 Ports.
www.ebay.com
You might want to read Kern Dogs thread about four wheel discs & getting his brakes to lock up... He's done the work & spent money on all the parts testing till he got it right...
'68 Coronet R/T
Well-Known Member
I didn't even see where it listed the bore size?Plan on sending it back... First, your running discs in the front, that's a four wheel drum M/C.... Second you'll want no bigger than a 1 1/16th bore, preferably a 1" bore...
If your not running a booster you'll need a smaller bore M/C to try to compensate... You wind up trading pedal travel for pedal feel...
Might even drop down to a 15/16" M/C like this one..
Mopar 15/16 bore master cylinder A B E body Cuda Charger 4 bolt cast iron | eBay
This is a new in the box cast iron master cylinder for Chrysler disc brakes 1 /2 -20 and 9/16 -20 Ports.www.ebay.com
You might want to read Kern Dogs thread about four wheel discs & getting his brakes to lock up... He's done the work & spent money on all the parts testing till he got it right...
So y'all are saying I should have ordered a '73-'76 A-body master cylinder like the one you linked to?
Bore size = pedal effort & pedal travel... But also a 4 wheel drum M/C woll have residual pressure valves in both ports.... The port to the rear drum brakes needs one, it help keeping the wheel cylinders from leaking & keeps the pistons in contact with the brake shoes... If you use that same residual pressure valve on disc brakes the brakes will drag constantly causing them to overheat... Also on a drum M/C the front & rear reservoir are the same size.. But since disc brakes need extra fluid volume a disc brake M/C has a small side for the drums & a larger side for the discs...
'68 Coronet R/T
Well-Known Member
Okay, I read the thread you recommended and my question was about the proportioning aspect. You answered that for me, so I will place an order for that 15/16" bore, disc/drum master cylinder. Thanks.
Many here (myself included) have earned this info the hard way.... It's better to learn from our mistakes and give yourself a better chance of getting it right...
Not saying it'll be perfect.. Hopefully it will but there's always variables..
'68 Coronet R/T
Well-Known Member
The master cylinder from Year One comes with two new seals for the push rod. The 15/16" bore cylinder does not. Does anyone have a source for these rod seals/gaskets?
While waiting I started working on the left front fender. Removed the undercoating with a heat gun and chisel, then began media blasting with crushed glass.
Things were going great until I ran out of media. Couldn't believe I didn't have any more on hand.
So now I need to move on to another project. Fortunately there is a whole bunch more to do on this car.
While waiting I started working on the left front fender. Removed the undercoating with a heat gun and chisel, then began media blasting with crushed glass.
Things were going great until I ran out of media. Couldn't believe I didn't have any more on hand.
So now I need to move on to another project. Fortunately there is a whole bunch more to do on this car.
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'68 Coronet R/T
Well-Known Member
Should I order an adjustable push rod for this new master cylinder?
theman440
Well-Known Member
You should be able to use your old one - don't use ANY pushrod that does not use the thick square rubber o-ring on the end of it and always replace it anytime you pull it out. That's what keeps the rod from falling out of the master. When I converted my '66 Coronet to '73-'76 A body disks I reused my original single pot '66 master cylinder push rod in the newer style master, then I reused it again in a Mopar Performance aluminum master cyl. when I put Wilwood discs on the rear of the car.
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theman440
Well-Known Member
'68 Coronet R/T
Well-Known Member
I ordered the 15/16" master cylinder and after closer inspection of my push rod, I ordered this one:
I doesn't have a boot on it, so wondering if I need to get one of them. Not sure what it's function is?
I doesn't have a boot on it, so wondering if I need to get one of them. Not sure what it's function is?
Where did you get the adjustable brake pushrod?
'68 Coronet R/T
Well-Known Member
Right Stuff RC14: Universal Adjustable Brake Push-Rods for Select Mopar Manual Disc Conversion Kits - JEGS
Get the Best Performance with Right Stuff Universal Adjustable Brake Push-Rods for Select Mopar Manual Disc Conversion Kits RC14 parts at JEGS. Shop Now at the Guaranteed Lowest Price!
www.jegs.com
Right Stuff RC14: Universal Adjustable Brake Push-Rods for Select Mopar Manual Disc Conversion Kits - JEGS
Get the Best Performance with Right Stuff Universal Adjustable Brake Push-Rods for Select Mopar Manual Disc Conversion Kits RC14 parts at JEGS. Shop Now at the Guaranteed Lowest Price!
Thanks, the Dr Diff pushrod I used on the GTX has a heim joint, without the flats the brake light switch sometimes doesn’t reset. It would be easier to replace the pushrod instead of reworking the mounting for the brake light switch.
'68 Coronet R/T
Well-Known Member
Yes, I had looked at others and thought the same thing. Plus most of the others were twice the price.
This one looks correct.
'68 Coronet R/T
Well-Known Member
Master cylinder installed:
The adjustable push rod worked great and provides good contact with brake light switch.
As you can see the steering column is in place. I didn't anchor it solid yet.
I also installed the emergency brake and forward cable.
The adjustable push rod worked great and provides good contact with brake light switch.
As you can see the steering column is in place. I didn't anchor it solid yet.
I also installed the emergency brake and forward cable.
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