Re-Rebuilding the 440-493 in a 1970 Charger

[Mopar Hunter]

I had to gut my distribution block on my four wheel disc brakes, they work excellent now.

 

[moparedtn]

This car had 4 wheel 10" non power drums when I bought it. It actually stopped okay. Not great but okay.
In 2012, I was curious about trying a 4 wheel disc and manual master cylinder arrangement. After trying 4 different master cylinders of differing sizes, I put the power stuff back on because I couldn't get the brakes to feel right. All 4 setups gave a hard pedal and terrible braking. Months afterwards, I saw that I had a disc/drum proportioning valve in place. Maybe I would have had better results with NO proportioning valve. Also, I had those big 2.75" iron front calipers with 1.5" rear calipers. I suspect that the front to rear bias was way off. The Mopar setup of a large caliper up front was matched to self energizing rear drums and a fixed proportioning valve. Even those cars sometimes had rear wheel lockup.
Now I have 13" front rotors with dual 1.59" calipers and the same 11.7" rear rotor size with 1.5" single piston calipers. This is an OEM setup for a 1994-2001 Mustang GT.

10" - yikes.
The 11" all the "muscle" models came with stock were/are light years better, of course...
drums to drums speaking anyways.

Although a Mustang is I'd imagine a smaller. lighter car than the Charger - those sizes seem more than adequate to me.
What did you not like about that setup?

 

[Kern Dog]

Although a Mustang is I'd imagine a smaller. lighter car than the Charger - those sizes seem more than adequate to me.
What did you not like about that setup?

In June of this year, I started making some changes.
From 2006 until 2012, I had the popular 12" Cordoba front rotors with 2.6" iron calipers with the Dr Diff 11.7" rear discs. I was using a '75 Dart power brake booster and 15/16" master cylinder. Braking was okay but not spectacular. I'd driven manual front disc A body cars and was impressed with the performance and feel so I decided to try converting the car to a manual master cylinder. I had a Master Power MC that was the biggest bore size in my stash...It may have been 1 1/8" or 1 3/16". It must have been meant for power applications because it gave an extremely hard pedal. The braking action was terrible though. I tried another that was 1 1/32". It felt about the same. I tried the iron 15/16" MC that was in the car before but this time with no booster. Braking improved but it was still not safe and not as good as it was with the booster. I ordered and installed a Dr Diff 15/16" aluminum master cylinder. It felt the same way. I couldn't skid the tires on my dirt driveway so I figured it wouldn't skid on pavement either. Four master cylinders with similar feel: Hard pedal with pitiful performance. I put the power booster back in and just admitted defeat.
Awhile later, I noticed that I somehow missed that all along, I had the stock disc/drum proportioning valve in place. A 4 wheel drum and a 4 wheel disc system is supposed to use the wheel cylinder or the caliper bore size as the "proportioning". I swapped in a 4 wheel drum distribution block that has no proportioning. Braking improved but it still wasn't awe inspiring.
I swapped in larger front calipers, going from 2.6 to 2.75. If there was any improvement, it wasn't much.
Sometime later, I pulled the brake pedal and drilled a hole above the stock hole....the hole where the brake pedal pushrod is attached. The higher hole improved the pedal ratio so that for every inch of travel of the pedal, the master cylinder saw more movement. In effect, I improved the leverage.
Finally the brakes felt pretty good. Again, not awesome...just good enough.
Then I swapped in the Tremec 5 speed and with it came an aftermarket clutch and brake pedal set. Of course, the brake pedal pushrod went back to the stock position and I lost that extra leverage. Since then, I've considered pulling the pedals out to drill that extra hole. Power brake systems use a reduction in the linkage to balance out for the assist they have. The relocated hole in a manual setup should be more of an improvement than the same increase in a power system since the linkage is not reduced.

 

[Mopar Hunter]

Electric brakes?

 

[68 Sport Satellite]

I've read that cars as heavy as mine are hard to stop with a manual master cylinder. That may be true. The car weighed 3940 before tearing it down in June. The Borgeson steering box and stock Idler and Pitman arms shaved 14 lbs. The new front brakes shaved another 14 despite the larger rotors. The switch from the A body vacuum booster and iron MC was another 15 lbs. I swapped rear tires for ones with shorter sidewalls. With all of this, I could be under 3900 with these changes.

I can tell you that if you disregard brake fade with repeated fast speed braking, the 2 manual drum cars I've driven both stopped very well. One is Dennis H's 1969 Coronet RT with 440 (about the same weight as your car - 3800-3900 lbs) and the other was my 1967 Impala SS with 327 that I drove as a daily driver for 15 yrs (was my dad's old car). That one had 11" manual drums all around and I never wanted for braking power. At sub-20 mph speeds I could get it to stop fairly quickly and it wasn't that much of a leg workout and had excellent pedal feel. That car weighed about 3500 lbs.

 

[Kern Dog]

I just read this on another site.....

...Another item that is worth mentioning is the proper way to bleed power steering and hydroboost. Pretty much 90% of people think just starting the engine and turning the steering wheel back and forth is the proper method to bleed the system. The actual correct way to bleed the system according to steering engineers I work with is to lift the front wheels off the ground, start the engine and turn the steering wheel lock to lock 2 or 3 times then, turn off the engine, exit the vehicle and turn the wheels lock to lock about a dozen times by using the actual tire/wheel. The difference is the motion and pressures inside the box initiated by the movement of the pitman side of the gear box instead of the selector shaft side (steering wheel side). When it was explained to me it made perfect sense but I don’t recall all of the details but has something to do with creating high and low pressures inside the box to push the bubbles out. That procedure works great the first time, every time....

I have not tried this. It never occurred to me. I did saw the wheel back and forth several times but I never pushed the wheels lock to lock from the outside. I don't understand how that would help but it is easy and free...Like the girl down the street.

 

[1STMP]

Hello KD,
Just my .02, but it looks to me that the lifter
bases are flat on those 3 lobes. That would
explain the odd wear pattern on the cam
and the scratches/gouges running across
the lobes.
Have you pulled one out to see if they're
flat?
In any case, it's really a bummer you have
to tear that engine down....again.

 

[Kern Dog]

There are some things that we never fully understand.
I believe that the problem originated with the oil. The engine ran fine for years with Valvoline VR1. It failed within a year with this weird high detergent synthetic oil. One or two lobes usually means a tight lifter bore or a lifter that isn't rotating but I had 10 lobes all failing about the same time.

 

[Cheapsunglasses]

I’ve always been skeptical of synthetics for our older cars. Some modern convinces I can embrace, but oil, no, I’ll stick with conventional.

 

[68 Sport Satellite]

There are some things that we never fully understand.
I believe that the problem originated with the oil. The engine ran fine for years with Valvoline VR1. It failed within a year with this weird high detergent synthetic oil. One or two lobes usually means a tight lifter bore or a lifter that isn't rotating but I had 10 lobes all failing about the same time.

the VR1 is synthetic high zinc and your car ran great for 5 yrs on this stuff.
What high detergent synthetic oil caused the motor's demise and why had you switched from VR1?

 

[hunt2elk]

the VR1 is synthetic high zinc and your car ran great for 5 yrs on this stuff.
What high detergent synthetic oil caused the motor's demise and why had you switched from VR1?

You can buy VR1 in a non synthetic as well. That's what I run anyway....

 

[68 Sport Satellite]

You can buy VR1 in a non synthetic as well. That's what I run anyway....

didn't know that!
KD, can you clarify if the VR1 you ran for 5 years without trouble was conventional or synthetic?
I'm using Amsoil 10-40 Z-rod synthetic and no issues on my motor.

 

[Kern Dog]

the VR1 is synthetic high zinc and your car ran great for 5 yrs on this stuff.
What high detergent synthetic oil caused the motor's demise and why had you switched from VR1?

The API rating of SN means that it is the highest detergent rating available. That detergent works against the zinc in the oil because it scrubs it instead of letting the zinc cling to the metal.

 

[Kern Dog]

I tried bleeding the hydraulic system using the method shown in post #666. It did not help at all.
In fact, the steering assist now is struggling. With the other pump, the rebuilt one, the steering assist did work at first but the HB never did. Then it got to where the steering assist was notch and only at higher rpm’s.
Now it seems that this pump is starting to fail. The steering assist worked fine but the HB didn’t. It is showing the same symptoms as the other pump before it quit completely. This is extremely annoying. The belt doesn’t appear to be slipping. It isn’t squealing. Can it be that this hydroboost unit is killing these pumps ? I’m going to feed the steering box directly from the pump to see if it works normally that way. I’ll report back soon.

 

[NoCar2023]

Is it possible the hoses are crossed at the h-boost?

 

[moparedtn]

I tried bleeding the hydraulic system using the method shown in post #666. It did not help at all.
In fact, the steering assist now is struggling. With the other pump, the rebuilt one, the steering assist did work at first but the HB never did. Then it got to where the steering assist was notch and only at higher rpm’s.
Now it seems that this pump is starting to fail. The steering assist worked fine but the HB didn’t. It is showing the same symptoms as the other pump before it quit completely. This is extremely annoying. The belt doesn’t appear to be slipping. It isn’t squealing. Can it be that this hydroboost unit is killing these pumps ? I’m going to feed the steering box directly from the pump to see if it works normally that way. I’ll report back soon.

What the evidence is starting to indicate, yes - that HB unit is the unproven wild card in the equation, after all.

 

[moparedtn]

didn't know that!
KD, can you clarify if the VR1 you ran for 5 years without trouble was conventional or synthetic?
I'm using Amsoil 10-40 Z-rod synthetic and no issues on my motor.

What type of cam are you running and in what engine?

 

[Kern Dog]

I am humble enough to admit when I am an idiot and make mistakes.
Regarding the “hoses crossed” reference: Even Dr Diff suggested that. I do have the hoses in the right place. That is not the problem here.
I think there is something wrong with the HB internally. The fluid seems to bypass the brakes but somehow makes it to the steering box. Also, the fluid has gotten dark quickly. Not black but it starts out clear and gets gray. I’ve spent $76 in fluid and I have to buy more because every time I have to take the pump out and apart, I have to buy more. This sucks.
I have the pump out again for what may be the 6th or 7th time.

 

[moparedtn]

You can buy VR1 in a non synthetic as well. That's what I run anyway....

This has been proven to me before my own eyes as well for a number of years now.
I absolutely swear by full synthetic for the modern engines designed for such - but for our older tech
flat tappet engines, synth is absolute death - high zinc conventional only!

 

[68 Sport Satellite]

What type of cam are you running and in what engine?

451 big block with a mild Lunati Voodoo 60302 hydraulic flat tappet cam. 0.475" lift and duration at .050" is 220/226, 112 deg LCA