Adjustable brake push rod?

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69413valiant

69413valiant

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Im going to be running the master cyl off of a chrysler 5 ave with the plastic reservoir in my 69 valiant. Do I need to use a adjustable brake push rod? Im already running 73-up brakes.
 
Is this a manual MC? If so, will you use a 69 pedal rod and does the rubber bushing lock into the MC piston? Do you need a 2-4 bolt adapter? Most likely, the brake pedal will wind up very close to the factory location. Adjust your lamp switch, regardless.
 
Realizing this is an old thread, but here goes. I have too much throw in my break pedal and its screwing up the switch. Brakes were converted to a dual reservoir MC. The manual shows a stop but I don't believe the MC had threaded holes for a stop.
1966 dart. Was a 273 car, now a 318.
If I use a shorter push rod, will it pull the piston too far out? Will I have enough throw?? Any help us appreciated
Jim
 
pyrojim said:
... its screwing up the switch. ... If I use a shorter push rod, will it pull the piston too far out? Will I have enough throw??
Jim
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Remove the switch until you bolt the pedal up. Then install and adjust the switch (slotted hole). The switch shouldn't interfere w/ pedal motion, just sense it.

The brake pedal doesn't push or pull the MC piston (unless you use your foot). The MC should position the rod w/ its spring and stops. The pedal just goes along for the ride. You only need a different length rod if the pedal doesn't sit where you want it. Ex., you don't want the pedal bottoming out on the floor before the MC hits its stop, and you don't want it sitting way above the gas pedal, unless you drive w/ 2 feet (like I do and they might now teach in driver's ed). Thus, neither rod, nor pedal, nor switch should affect or interfere w/ the "throw". It is common sense once you understand this.
 
Too much pedal travel may indicate a problem.Does the Throw diminish with multiple stabs on the pedal?Does the pedal feel spongy?Has the throw been increasing over time? If there is a yes in there anywhere, your brakes are not right.Fix that first.
 
AJ/FormS said:
Too much pedal travel may indicate a problem.Does the Throw diminish with multiple stabs on the pedal?Does the pedal feel spongy?Has the throw been increasing over time? If there is a yes in there anywhere, your brakes are not right.Fix that first.
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if, you used a conversion plate to bolt the master cyl. up to the firewall,just lengthen the rod the thickness of the conversion plate. I threaded mine, screwed a threaded rod coupling on it, then welded it w/ the exact diff. adjusted in to it. then ground it down and dressed it up. has worked great so far! :coffee2:
 
69413valiant said:
Im going to be running the master cyl off of a chrysler 5 ave with the plastic reservoir in my 69 valiant. Do I need to use a adjustable brake push rod? Im already running 73-up brakes.
Click to expand...

yea i know its an old thread. but i want to post good info on the subject..


the 5th ave mc has a shallower pushrod bore then the stock 73 style mc. as long as you run an adapter plate like this one http://arengineering.com/products/master-cylinder-adapter-no-studs/ which is the same thickness as the difference in bore depth then you are fine with the stock 73 style push rod.
 
When I Installed a late model master cylinder with the 4 to 2 bolt adapter, I installed an adjustable rod. I had to adjust the brake light switch.
 
Ted Carlson said:
When I Installed a late model master cylinder with the 4 to 2 bolt adapter, I installed an adjustable rod. I had to adjust the brake light switch.
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who's adapter was it? was it ar engineerings?

I've put the late model mc using the adapter plate i posted above in two different cars using the stock 73 style push rod. never had to adjust the brake switch on either car. bolted it in, bled the brakes and away i went.
 
BillGrissom said:
Remove the switch until you bolt the pedal up. Then install and adjust the switch (slotted hole). The switch shouldn't interfere w/ pedal motion, just sense it.

The brake pedal doesn't push or pull the MC piston (unless you use your foot). The MC should position the rod w/ its spring and stops. The pedal just goes along for the ride. You only need a different length rod if the pedal doesn't sit where you want it. Ex., you don't want the pedal bottoming out on the floor before the MC hits its stop, and you don't want it sitting way above the gas pedal, unless you drive w/ 2 feet (like I do and they might now teach in driver's ed). Thus, neither rod, nor pedal, nor switch should affect or interfere w/ the "throw". It is common sense once you understand this.
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I understand the concept. But it seems to me that their should be the locking grommet on the end of the push rod into the master cylinder. the pushrod now just floats freely. So, if my foot comes off the brake and pulls the pedal up a little too far, it pushes on the switch and locks the brake lights on.
I've ordered the bushing/grommet for the pushrod, just not sure that it will fit in the slot inside the MC.
Thanks.
Jim
 
pyrojim said:
I understand the concept. But it seems to me that their should be the locking grommet on the end of the push rod into the master cylinder. the pushrod now just floats freely. So, if my foot comes off the brake and pulls the pedal up a little too far, it pushes on the switch and locks the brake lights on.
I've ordered the bushing/grommet for the pushrod, just not sure that it will fit in the slot inside the MC.
Thanks.
Jim
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pushing on the switch shuts the brake lights off.

yes use the little rubber thing inside the new mc. its dangerous not to have it lock in the master cyl. you pull up on the pedal and the rod falls out of the mc. then you have no brakes.
 
abodyjoe said:
pushing on the switch shuts the brake lights off.

yes use the little rubber thing inside the new mc. its dangerous not to have it lock in the master cyl. you pull up on the pedal and the rod falls out of the mc. then you have no brakes.
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Hey Joe.
Do you know if the original grommet from the original pushrod is universal???
Bought this car as a basket case, I have no clue the make of the MC?
 

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i'm thinking they are but i'm not sure.. i got mine from RMS when i did my change over.

i went from the mc you pictured (73-up disc brake mc) to the newer alum with plastic mc and used the same push rod and new grommet.
 
abodyjoe said:
i'm thinking they are but i'm not sure.. i got mine from RMS when i did my change over.

i went from the mc you pictured (73-up disc brake mc) to the newer alum with plastic mc and used the same push rod and new grommet.
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Thanks Joe!!!
 
Abodyjoe, is the manual pushrod different from a 65 as opposed to a 73? Asking because I'll be making this swap soon
 
Didn't some cars have a light spring that holds the rod into the cylinder? I sure remember seeing that on a Mopar of some model.
 
salinasjoel said:
Abodyjoe, is the manual pushrod different from a 65 as opposed to a 73? Asking because I'll be making this swap soon
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doesn't the 65 push rod bolt into the master cyl? the 73 style is a separate piece all together and only has that rubber thing holding it in..
 
maybe it is the same for a 65. i bet you can call brewers and atleast ask.

http://www.brewersperformance.com/proddetail.asp?prod=BPR-A


BPR-A.jpg


Reconditioned brake pedal to master cylinder pushrod, for manual brake applications, includes pushrod, nut and bolt with new o-ring, and locking grommet for master cylinder. Fits all 1963-76 A-body applications, measures 6 1/2" overall length. As available.
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Gentleman: I caught this thread doing research for a 4 to 2-bolt aluminum MC switch. "Dr Diff" says their 2-bolt MC with provided 4-bolt adapter will accept the stock manual brake rod; at least for a 71 DART/Demon. The shallower depth of the 2-bolt MC is offset by the depth of the adapter. Does anyone know if a rebuilt/replacement 1979 or newer (non-front wheel drive) MC with the stock manual rod?

BTW, thanks "Abodyjoe" for your posts and info.
 
DLKessler said:
... Does anyone know if a rebuilt/replacement 1979 or newer (non-front wheel drive) MC with the stock manual rod?
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Not sure why you suspect front-wheel drive would matter.

Here is how I determined my brake pedal will be in about the same place w/ the MC for a 95-99 Breeze w/ ABS ($25) on adapter plate ($28), using the manual brake rod for my 64 Valiant. The thickness of the adapter plate doesn't make a tremendous difference in where the pedal will sit. You should always remove and re-position the brake lamp switch. People must be foolish if they think the the switch won't need moving. Some seem to think it should act as a "pedal stop" (I think false). The factory put adjustment slots in it.

I put a new rubber bushing on the end of my manual rod. Seems it will lock it in fine in the new MC piston. Indeed, I wasted one in a test fit when I had to remove it to install the boot and the rod wouldn't come out without destroying the bushing.

BTW, I mounted an adjustable proportioning valve on the bracket I took from an Intrepid. That will allow me to easily use front disks later.
 

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DLKessler said:
Bill, I pulled the "do not use master cylinders from FWD cars" from this MOPAR ACTION tech article: http://www.moparaction.com/tech/archive/disc-main.html

The exact mechanical reason was not stated but, since the used a "!" at the end of that statement I figured there was a real good reason.

Thank you for the pictures and input.
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http://arengineering.com/ used to have the reason posted. can't find it on their site now though. its something about how its plumbed. i think it was only certain year fwd master cyl.
 
Thanks for the info on FWD MC's. Every bit helps. I read that Ehrenburg article in the past, but didn't catch that. Prompted my intereset because I put an MC from a FWD car (95-99 Breeze w/ ABS) in my three 60's Mopars. Seems to work fine. Perhaps Ehrenburg meant 80-90's K-cars. Many newer cars have MC's that seal vacuum where they bolt to the booster. K-cars could be like that and not bolt up correct to a Dart booster. The Breeze MC works for me in 3 different setups - manual, on Breeze (or Intrepid) booster, and on C-body booster (via 2-4 adapter plate).
 
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