SSBC conversion issue?!

[66SportFury]

I'm still on the phone with SSBC about the issues!! Really no change in the brakes going to the new booster and MS setup they sent me. Car is very hard to stop. Not as bad, but not good enough. Hard brake pedal still. I've replaced the rear WC and rear rubber line that was clogged and thought that would have done it, but no good. They want me to do a pressure test at the front calipers to make sure there is 1200 to 1500 psi at the bleeders. They sent me a pressure gauge kit to do this. This weekend that will be done. I'm just running out of ideas of how to fix this. Anyone use SSBC kits before and run into this issue? The good part is that I haven't spent a dime on parts from SSBC as of yet and they are willing to get this right. It seems the more I press the pedal the worse it gets to get the car to stop. If I press lightly on the pedal the car will seem to stop faster! I don't get that at all. I've been doing this **** for 35 plus years and never ran into this before with brakes. Any ideas guys?

 

[commando1]

Go back to square one and check to see how much vacuum your engine is drawing at the intake manifold at idle.
Can't do anything until then.
Waiting......

 

[66SportFury]

Nah, that's not an issue. I'm running a separate electric vacuum pump due to the cam. It's pulling at least 20/22 inches of vacuum. I'm pretty pissed at this point.


So far I replaced the rear WC, brake lines to the rear, rubber line to the rear, booster, MC. I just don't get it. I'm going to go through the front brake system this weekend, but it's all new!! I will do the pressure test that SSBC is asking me to do too. It's like WTF is wrong with this system.

 

[saylor]

IF BOOSTER IS NOT OPERATING GIVING A VERY HARD PEDAL

1. Disconnect the vacuum hose from the booster check valve and check the vacuum level at this point with the engine running with a vacuum gauge. You should have at least 18" vacuum to the booster. Anything lower will begin to give a hard pedal. lf the vacuum level is below 18" you may be able to tune the engine and bring the vacuum level up to that level. If the vacuum level is around 16" the addition of a vacuum reserve canister will improve the braking. If the vacuum level is below 16" you will need to add an electric vacuum assist pump to supplement the engine vacuum.
   
2. If the vacuum level at the check valve is 18" check that the booster check valve is working. Disconnect the vacuum hose at the check valve and attach a piece of tubing. Blow into the valve. If air passes through the valve is defective and must be replaced. Also look into the hose attachment neck on the check valve and be sure there is no obstruction inside the valve.
   
3. Check your booster for a vacuum leak. With everything hooked up run the engine at moderate speed. Release the accelerator and turn the engine off. Wait 90 seconds and apply the brakes. If the brake applications are power assisted there is no leak. If there is no power assist the booster is defective and must be replaced.

IF THE BOOSTER IS OPERATING BUT YOU STILL HAVE A HARD PEDAL

1. Your combination valve may have tripped shutting off fluid flow to the front or rear brakes. This condition will produce a very hard pedal. Check that fluid passes through the valve to both the front and rear by cracking a bleeder screw and observing a good flow of fluid. If one half of the system does hot have flow, re-center the valve.
   
2. You may have frozen rear wheel cylinders or frozen caliper pistons. If these components freeze you can get a very hard pedal.
   
3. Your pedal ratio may be too low. Check your pedal ratio. The pedal ratio must be in between 4:1 to 5:1. Some of the older cars that had power brakes used a ratio of almost 1:1. If you add a vacuum booster to this type of car you will have a very hard pedal. Typically we are talking about late 50's cars. Adjust ratio as necessary.
   
4. Your booster may be undersized for the weight of the vehicle or the bore size of the master. If you try to use a small diameter booster such as a 7" street rod booster for a heavy car you will get a very hard pedal. Compounding the problem is an attempt to use a large bore master (1-114" or larger) on a small booster.

 

[commando1]

Nah, that's not an issue. I'm running a separate electric vacuum pump due to the cam.

I still have the feeling...

 

[66SportFury]

I still have the feeling...

Still have the feeling of what?

 

[commando1]

The symptoms strongly suggest the MC.
You replaced the MC.
You swapped to a vacuum pump.
I'm guessing the pump isn't keeping up with the vacuum draw required by your MC on braking.
Just a guess on my end, mind you... I'm not Rick Erhenberg

 

[66SportFury]

The symptoms strongly suggest the MC.
You replaced the MC.
You swapped to a vacuum pump.
I'm guessing the pump isn't keeping up with the vacuum draw required by your MC on braking.
Just a guess on my end, mind you... I'm not Rick Erhenberg

Believe me, I've checked the vac pump to make sure it's doing as it should and tested it a few times to make sure it's pulling the correct amount of vacuum and it passed, but I do understand what you're saying. I do have a vacuum canister I purchased. I can use that to see if it helps. I can connect it to the pump and use it in conjunction. It wouldn't hurt to try it. This is very frustrating when everything is new and still it doesn't work!

 

[commando1]

I feel your frustration. Hang in there.
The impossible takes a little bit longer...

 

[66SportFury]

I did the pressure test and came up with 1100 psi, so that is a bit low. It should be 1200 to 1400 psi. I'm waiting for a response from SSBC. I think the booster is to small. It's has a 7" dual diaphram booster on it, but maybe it's the MC bore being to large. I'm just at my wits end..!!!

 

[66SportFury]

SSBC said the pressure readings are good. They said to buy a new set of pads and to go with a set of Hawk HP pads at a cost of $135. Crap!!!!

 

[commando1]

What a wonderful and relaxing hobby...

 

[70bigblockdodge]

This is why I still like the scarebird set up it uses oem style stuff, I know there is a hokey insert but the parts are all backed by probably a billion miles of testing in real world, all the ram trucks and all the ltd./galaxy and mopar cop car miles. In another point is most 4x4 dodge trucks are in the 5500-6000 lbs. range way heavier than a c-body so the calipers and pads have enough area for a fully loaded c body, using later model disc brake master, free factory engineering.

 

[66SportFury]

I hear ya. I'm going to give the pads a shot before I do anything else. I have the feeling this should do it since the fluid pressure is where it should be. Plus, I was looking at the brake pedal rod and it is on a slight angle and not going straight into the booster. I will need to adjust this so it's straight.

 

[commando1]

I was looking at the brake pedal rod and it is on a slight angle and not going straight into the booster. I will need to adjust this so it's straight.

I can't understand how the pedal assembly would be crooked.
Maybe you reattached the push rod to the wrong side of the pedal?

 

[66SportFury]

I can't understand how the pedal assembly would be crooked. Maybe you reattached the push rod to the wrong side of the pedal?

Check out the picture below. This is what I got going on with the push rod. I also found out the PO has the lines going into the master Cly backward..! WTF..!! The rear and front lines need to be switched around.!!

 

[Ripinator]

Check out the picture below. This is what I got going on with the push rod. I also found out the PO has the lines going into the master Cly backward..! WTF..!! The rear and front lines need to be switched around.!!

Is the booster upside down ?

 

[66SportFury]

No, it can only go in one way. I have to slot the mounting bracket more so the push rod will be straighter. OR,.It's possible that the brackets are in upside down. I'm not at the car right now, but I will check on that.

 

[commando1]

No, it can only go iwrong in the first place. Don't slot them. one way. I have to slot the mounting bracket more so the push rod will be straighter. OR,.It's possible that the brackets are in upside down. I'm not at the car right now, but I will check on that.

A disc brake master cylinder has a big resevoir For the front brakes and a smaller resevoir for the rears. The front resevoir is closest to the master cylindar. The front brake line goes to the larger resevoir closest to the m/c.

If you have to slot the bracket, something is wrong. Don't slot them.

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[66SportFury]

My setup uses a Corvette MC. Both reservoirs are the same size. SSBC pointed out from a picture I sent that the lines are crossed. The way it is in my car now,is the closest port (back side of the MC) to the power booster is going to the front brakes and the other is going to the rear brakes,..front side of the MC. It should be the other way around since this is a Corvette master cylinder. They work the other way around compared to a Mopar MC.