Un-boosting power assist brakes??

[ValiantOne]

Hey All,

Among the many complaints I have about my new 73 Dart is the BRAKES!!!

I was really pumped up when I found out that the car had front discs on it. That was a major reason for the purchase.

The problem is, if you LOOK at the brake pedal sideways, it leaves black screetch marks all the way down the road. The brakes are soooo oversensitive it isn't even funny. Not fun to drive at all. I have locked them up so many times it is just plain annoying.

I was wondering if anyone has un-vacuum boosted their disc brakes before and what that would entail. Could it possibly be as simple as taking of the booster and finding a spring clip for the master cylinder actuator rod? Or am I in the market for an adjustable rod from someone?

Any info would be helpful.

Thanks!

Chris E.

[Jim_Lusk]

You can use the same master, but you will need a manual brake pushrod. The brake lines will be kind of long, too.

[73swinger]

OK OK...you must be getting sick of my constant defence of 73 Darts, but honestly. Mine has power discs in front and they are actually quite user friendly, in fact I don't think they've ever locked up on me. Is it possible that there could be some other issue? You could always add a few hundred pound to the front like I did 

[ValiantOne]

You can use the same master, but you will need a manual brake pushrod. The brake lines will be kind of long, too.

I was planning on cutting down and re-flaring the existing lines, 'cause it would really move the cylinder closer.

I do happen to have a manual brake pushrod too  Were they all the same length?

Thanks!

[chargerbr549]

I would be curious to find out what is wrong also with the oversensitive brakes I am leaning towards the booster maybe having some issues. A friend of mine and I both have 69 R/T Chargers optioned with the same power drum brake system, my brakes were never that great with the stock 440 and when I put a big cam in it with not much idle vacuum they flat sucked they were a little grabby when you first touched them and then they were like stepping on a brick and the car would hardly slow down, then I converted it to manual  big disc brakes and now talk about awesome pedal feel and great brakes. Now on my friends Charger his brake system is still all stock however I drove it once and it scared me half to death I barely even pushed on the brake pedal and it locked up all the wheels going about 50mph talk about a ride, the only way to use the brakes it to barely move the pedal and let the brakes do all the work because if you push it very hard or fast it will lock the brakes up almost instantly! He's used to them but I think he would like them to work alot better than they do. I see he's not the only one that has this oversensitive brake problem.

Kevin

[68_Val_Sedan]

 


My 68 300 has very touchy power brakes as well.    I haveto get used to driving it each time I get behind the wheel.  I am waitign till I put the disk brake on the front before removing the booster ...

[flyboy01]

Hey All,

Among the many complaints I have about my new 73 Dart is the BRAKES!!!

I was really pumped up when I found out that the car had front discs on it. That was a major reason for the purchase.

The problem is, if you LOOK at the brake pedal sideways, it leaves black screetch marks all the way down the road. The brakes are soooo oversensitive it isn't even funny. Not fun to drive at all. I have locked them up so many times it is just plain annoying.

I was wondering if anyone has un-vacuum boosted their disc brakes before and what that would entail. Could it possibly be as simple as taking of the booster and finding a spring clip for the master cylinder actuator rod? Or am I in the market for an adjustable rod from someone?

Any info would be helpful.

Thanks!

Chris E.

I would bet money that you have a manual master on your booster, that would cause that problem.

[ValiantOne]

Hey All,

Among the many complaints I have about my new 73 Dart is the BRAKES!!!

I was really pumped up when I found out that the car had front discs on it. That was a major reason for the purchase.

The problem is, if you LOOK at the brake pedal sideways, it leaves black screetch marks all the way down the road. The brakes are soooo oversensitive it isn't even funny. Not fun to drive at all. I have locked them up so many times it is just plain annoying.

I was wondering if anyone has un-vacuum boosted their disc brakes before and what that would entail. Could it possibly be as simple as taking of the booster and finding a spring clip for the master cylinder actuator rod? Or am I in the market for an adjustable rod from someone?

Any info would be helpful.

Thanks!

Chris E.

I would bet money that you have a manual master on your booster, that would cause that problem.

Manual master??? I thought by the late 60's all the residual check valves were built into the proportioning valve (or the cylinder itself). Or are you talking about something else?

Goes to show what I know. I thought they were the same. Hmm.

Sounds like Kevin and Chad know just what I am talking about. If I drive my truck or my 68 Val, and then get in the 73, I'm sure to lock them up, or at least send myself toward the dash board the first time I step on the brakes.

[sst3193]

Way back in the 70's when the gas crisis hit my Uncle put a Hi-mileage Cam in his '68 Galaxie and found that the car was nearly undrivable, because the brakes got way too sensitive. His fix back then was a small c-clamp on the vacuum hose. I laughed at him so, he took the clamp off and I nearly got myself killed just going around the block. Neeedless to say he put the clamp back!

[flyboy01]

Hey All,

Among the many complaints I have about my new 73 Dart is the BRAKES!!!

I was really pumped up when I found out that the car had front discs on it. That was a major reason for the purchase.

The problem is, if you LOOK at the brake pedal sideways, it leaves black screetch marks all the way down the road. The brakes are soooo oversensitive it isn't even funny. Not fun to drive at all. I have locked them up so many times it is just plain annoying.

I was wondering if anyone has un-vacuum boosted their disc brakes before and what that would entail. Could it possibly be as simple as taking of the booster and finding a spring clip for the master cylinder actuator rod? Or am I in the market for an adjustable rod from someone?

Any info would be helpful.

Thanks!

Chris E.

I would bet money that you have a manual master on your booster, that would cause that problem.

Manual master??? I thought by the late 60's all the residual check valves were built into the proportioning valve (or the cylinder itself). Or are you talking about something else?

Goes to show what I know. I thought they were the same. Hmm.

Sounds like Kevin and Chad know just what I am talking about. If I drive my truck or my 68 Val, and then get in the 73, I'm sure to lock them up, or at least send myself toward the dash board the first time I step on the brakes.

You can get a small piston manual master cylinder and a larger piston power master cylinder, the proportioning valve is seperate and sits about 18" below the master on the frame rail. If you rears were licking up, then I would say you need a new proprtioning valve, but if your fronts are, then you are overboosting. You have the exact same system on your 73 that I have on my 68 (has 73 k-frame and brake system)

[ValiantOne]

Ok, so you are talking about master cylinder bore size. I should have both of 'em laying around here somewhere.


Sorry, I thought you were talking about residual pressure check valves. My bad.

Thanks Fly

[kendog170]

I've got 74 discs without the booster and they work awesome!I believe you can now purchase those masters new pretty cheap too.

[MoPar_or _NoCar]

Sounds like Kevin and Chad know just what I am talking about. If I drive my truck or my 68 Val, and then get in the 73, I'm sure to lock them up, or at least send myself toward the dash board the first time I step on the brakes.

Cure = 6 Point Harness and Goodyear Stock Options!

[MVRCorp]

My 67 has manual brakes with discs on the front. I bought my master cyl. from MP Brakes ($85.00) and it works perfect.
I saved the rubber ring (retainer) to re-use by cutting the old plunger up with a die grinder.