Anyone have a CPP booster and master on their truck?

[1999corvette]

I have the CPP booster, master, and proportioning valve on my truck, front disc, rear drum.

I have bled and bled, the pedal just feels soft compared to my other cars, have not tried to drive it yet.

I have one friend that says his CPP setup seems to have a soft pedal as well.

There is resistance, but unlike my other cars, I can push the pedal down a lot further and it's not hard like those cars with the engine off.

Is this just the way these are?

[Captainfab]

I can't help you with your problem, but if you go over to the suspension forum, there is a rep from CPP that hangs out over there named Jeff. He seems to be really helpful.

[chris6499]

i have the cpp set up it feels ok to me it is softer than my newer trucks that came from the factory with the setup one thing i noticed when i first installed it is that i was use to the truck with 4 wheel drum and manual brakes and i was still trying to drive it like that

[markeb01]

Was the master cylinder bench bled before installing on the truck? It sounds like there could still be air trapped in the master cylinder. If it wasn't dead level when being bench bled, or if one of the reservoirs ever ran dry while connecting, filling the lines or bleeding, air trapped in the nose of the master cylinder will be almost impossible to remove without pulling the master and bench bleeding it again.

[1999corvette]

Yes, it was properly bench bled, and of course each wheel was bled of all bubbles as well.

By the way, I've been bleeding this sucker on and off for over a month (not everyday)

I just now bought a new master cylinder from Napa auto, for a 1970 Corvette, and it does have resistance.

The CPP master even after bench bleeding felt like the pedal was hooked up to nothing, no resistance whatsoever.

I wonder if it could be possible that these old trucks pedal ratio is more than modern cars because most of them came with non power brakes.

It has been over 2 years since I last drove the truck, so it's hard to compare to the stock brakes.

[roofingbloke]

I had the very same problem, a soft pedal untill you hit the floor, i endid up fitting complete new brake lines, turns out i had been sold the wrong master cylinder from CPP. (wrong bore size)

Jeff from cpp seems to be an ok guy, ask if you have been given the right part.

[markeb01]

Sounds like it might just be a defective master cylinder. I'm not sure how the CPP system installs compared to the Master Power setup I have, but in the MP installation instructions (page 4 item 2), they specify drilling a new hole in the brake pedal arm 2.5" lower than stock.
http://www.mpbrakes.com/uploads/prod...STRUCTIONS.pdf

I ran mine with manual front discs for a couple of years before installing the booster, and the pedal was hard as a rock. With the engine off it remains the same today with the booster in place. It's been over 10 years since I added the booster so I can't really remember if drilling the hole lower on the arm made any difference in pedal feel.

[jason65]

Did you move your brake rod down 1"? Where the rod meets the pedel asym. I belive it's 1" you'll have to check your instructions. I threw my instructions away 6 months ago.

[mbgmike]

Originally Posted by jason65

Did you move your brake rod down 1"? Where the rod meets the pedel asym. I belive it's 1" you'll have to check your instructions. I threw my instructions away 6 months ago.

usually its 1" down on quite a few vehicals we have a chart that I can't find right now. We are MPbrake dealers and they say 2.1/2" You may want to check the booster pin length to make sure its in contact correct. You should have a firm pedal with the brake kits.
Your mc should be fine if its off but that can be checked as well.
these components no matter the mfg all work the same. if its correct

THE EFFECT OF PEDAL RATIO AND BORE SIZE ON HYDRAULIC PRESSURE OUTPUT
Pedal Ratio Bore Size lbs input PSI out
6:1 1 1/8 75 453
6:1 1 75 573
6:1 7/8 75 748
5:1 1 1/8 75 377
5:1 1 75 477
5:1 7/8 75 623
4:1 1 1/8 75 302
4:1 1 75 382
4:1 7/8 76 499


Here is a link to MPbrakes pedal calculator
sorry chart is kind of messed up

http://www.mpbrakes.com/uploads/docu...alratiopdf.pdf

[1999corvette]

I double checked the instructions, there was no mention of drilling another hole on the brake pedal lever.

I did search CPP instructions on their site, not one for this exact set up, however there is another setup on a truck of the same era, and the pedal lever is re drilled

"As per the directions, Alan drilled a new hole in the pedal arm 1 inch lower than the original. The reason for this is that it makes the pedal less "touchy."

http://www.classicperform.com/tech_a...topBraking.htm

Maybe they forgot to mention that, I'll have to ask CPP to see what they say.

[JRBECK64]

I put a CPP Disc Brake conversion kit in my Sons 64 and that thing is almost to touchy compared to my newer trucks. I believe I remember drilling a new hole in the Brake Pedal to mount the rod from the Booster Assembly but that was 5 years ago. I will take a look at it today and let you know where we drilled it. I looked at it and we drilled the hole about an inch below where the original hole was for the original brakes. If I were you I would Bench Bleed the master cylinder again then try to bleed the lines. If that doesn't work then try a new master cylinder.
JRBECK64

[Heater63]

I went through the same issues; repeatedly bled and rebled, and tried different master cylinders; still my pedal is softer that I like.
Talk to another vendor, like Stainless Steel Brakes, et al; I think they will tell you that when you do a front disc conversion, even with the proper master, and all properly bled, you will not have that same "hard" pedal that you were used too with an all-drum set-up. You now have to build a lot more pressure (hence the proportioning valve to balance the two systems) and even with a bigger master cylinder, its hard to do. That has been my experience.

[Heater63]

If you move the hole for the pushrod down the pedal, you are lessening your leverage and you will have to appy more pedal force. If it is "touchy", move the hole down away from the pivot.

If the pedal is soft and travels too far, you should move the hole up towards the pivot point to increase your mechanical advantage.

Also, CPP mail-order sucks from my experience. Make sure you got a good/correct master, and make sure you bench bleed it properly before you install.

[absintheisfun]

I have had 1 experience with CPP, and it will probably be my last. I'll use LMC for life though.

My shopping list for my 63:

F/R sway
F/R disc (power), complete kit
Steering rebuild kit
Front susp. rebuild kit
tilt column w/shifter and wire harness adapter
Lokar trans linkage

Problems:
wheel bearings didn't fit. I ordered the same part number from a different vender and they fit, so I guess it was a weird flawed set (on both sides??)
missing mounting hardware for front sway
center link from wrong vehicle sent
Brakes missing pieces
steering wiring harness adapter never sent
Brake kit states it ships with lines/hoses, but I never got any.

Once all the problems were solved, all the pieces went in...
Pedal is WAAAAAAY SOFT. I need to make some adjustments/put in a new pedal assembly to make my push shorter because right now there is probably 8 inches of travel, and 6 inches of it is WAYY soft. So soft it is scary. When I get to the last 2 inches, it locks them up though and the truck screeches to a halt.