rear brake upgrade on 70 dart

[OldDart]

hey guys.... i just picked up this 70 swinger and am back in the mopar thing..... i have previously owned (in order) 67 polara 4-door, 66 coroonet 500 with a built 440 transplant, 68 cuda conv. with a 71 340 transplant. I'm just playing around with this thing and plan to keep it stock. It's originally blue/blue with 225/6 a/c, ps, pdb. I think the body is pretty sound though it has a pretty crappy brown paint job now and the interior is major ugly. It runs good, has a rebuilt carb, distributor, new battery, some front end parts replaced, alignment, major tune up, new cragar rims, good tires, etc. I know it's not fast like most of your cars but I love the old beast and I'm sure I got you beat on MPG! The first issuses: 1) hard to start. replaed coil, problem solved. 2) Trans leak, mostly when sitting - tightened pan and I think i got most of it. 3) Brakes don't work well - booster checks out, bad seal on one rear so rears will be done. Fronts (disk) look good by eye. I drove it home for $1000

Here are my questions. If you can help I would greatly appreciate it.

1) are there any cheap, junk yard upgrades for the rears with the 7.25 rear end?
2) The drums are shot, any recomended suppliers for good internet prices on drums, w/s kits, seals, shoes?
3) the brakes worked but felt like manual brakes. I vacume tested the master and it is fine. Do you think it is just becuse of the rears or is there a possibility that the front calipers have issues.
4) lastly, is there and EASY upgrade for the fronts to bigger disks........ thanks.... i'm hoping to get this thing stopping the best it cann but not spend too much.....
5) I don't see any proportioning valve - and I heard mention of a check ball for the power brakes, where is that and how can I check it..... no pun.

Also, looking for a/c controls, original front seat, front valance, radio/heater control bezel... thanks...

 

[68dodge]

I would try NAPA for the rear brake parts. They are a pretty good supplier and the price is not bad. I would also replace the front calipers, brakes and rotors. Then bleed the brakes until you get new fluid coming out. This way you know everything is new at the brakes. Any other issues that come up will have to be in the brake lines, master cylinder or the brake booster. The cost is not to bad to do this. It is better to be safe then sorry with these old cars.

 

[Vs29H1B]

I agree with 68Dodge on going through the brake system, since our lives are in the balance based on properly working brakes.

If your front disc rotors have proper run-out / thickness within factory specs, you can stay with those. The K-H factory disc setup used 4 piston calipers, which tend to have rust problems in the piston bores, when the car is not driven regularly. My 1971 Duster 340 has the factory K-H discs, and the disc brake engagement is slow and lazy, if the car goes undriven for long periods.
The solution is to either rebuild/replace the calipers, and an upgrade is available to stainless steel cylinder bores with a lifetime warranty. Pistons, fluid transfer tubes, and piston seals are available, if you wish to rebuild. Brake line hoses are being manufactured in Argentina, and are on Ebay regularly. These brake line hoses may also be available from Fine Lines, along with new metal brake lines.

Many times, poor brake performance in A bodies is due to mis-adjustment in the rear brakes. The drums and the other components are available, try NAPA, or search this site for exact part numbers and availability.

I'd look at the rear brakes, rebuild as necessary, look at replacing the rear drum wheel cylinders, see Rich Ehrenberg on Moparts for upgrading to better wheel cylinders.

Hope this helps.

PS --- your car looks GREAT for $1,000! Looks like NO RUST! Wish we had those cars back on the East Coast.

Please post what your findings and repairs are, to fix your problems. Thanks!

 

[OldDart]

Thanks a lot for the great info and advice!!! I am going to start with the rears. There is a leaky seal or w/c so i need to do the obvious first. I will see how it feels at that point and think about rebuilding the fronts as it has sat quite a bit.

More importantly right now, the thing isn't running right. It has had 100% tune up done including distributor, coil, wires, plugs, carb, valve adjustment, etc. The problem is a lot of little poppy backfires. When I drove it home it ran ok but I remember some of the little pops. Before I replaced the coil I moved the timing around because it was almost impossible to start. I finally realized the coil was roasting hot so i replaced it then it started right up. I had also in the process checked the compression and was good at 120-130. Anyway, when I went to drive it it after the coil it was popping a lot and couldn't get up. Under no load it would rev up and sound good and smooth it was just under load it had trouble. I don't have a timing light but I tried by ear in many different positions with similar results. My conclusion is that it probably needs a t-chain. My timing light is broken so I can't check for timing mark bounce. The only other thing I am not 100% on is the valve adjustment. I don't hear any clatter though so it is probably OK or at least not the cause of this problem. Any thoughts?

I also am trying to do some research for another car I want to build regarding rear ends. Probably a 63 valiant, I want a light, high-revving power plant in an extremely light car. I already have the motor I want in mind. My question is about the rear end. Because I am trying to keep the weight and rotating mass way down and for general simplicity I want to keep the 7.25 or something else that is as light. What I need to end up with is the 5x4.5 bolt pattern in a very light assembly that is maybe slightly wider than stock or stock width-- and the main thing is I want massive stopping power. I know about the front brakes from a 73 and newer . What about the back???? How can I get some massive brakes in a light but strong assembly. This is going to be about 300-350 HP but only about 180 torque. and 8000 red line. Oh, and it has to be disk because it has to look cool through the rims. Thanks!