CPP front disc brake swap, brakes sticking and smoking a bit - The 1947 - Present Chevrolet & GMC Truck Message Board Network

sixty4bigwindow · 04-20-2017, 03:27 PM

Ok so i finished doing the CPP front disk brake upgrade, bled the lines, fixed all the leaky spots. Went on a drive, and about 10 minutes in, it felt like my rig was slowing down and needed more gas pedal. Funny smell, knew it was the brakes when I pulled over and saw some smoke... i am running a combination valve and dual chamber MC from a 72 c10, mated to a power booster from a 77 c20 (i believe the model is correct, not quite sure,) and the stock pedal rod, with a modified bracket. After I let it sit for about am hour, the pedal went back to normal (it was super tight with no play during the issue.) I'm wondering if i need to get a shorter brake rod or just remove the booster completely? Figured Id come here first to see what you guys think!

Thank you in advance guys!!

forestb · 04-20-2017, 04:45 PM

I would try shortening the brake rod first. I had that same problem once.

Ben_Yeaton · 04-20-2017, 05:15 PM

I had an issue where my brakes would lock up, almost feel like the truck was slipping. Turned out to be the booster plunger (rod) that engages with the master cylinder. It was too long, making the brakes engage even without a foot on the pedal. And then as it got warm, it got worse. I would start there as well.

**The Rocknrod** · 04-20-2017, 06:28 PM

Check Booster Pushrod Adjustment - Not Brake Pedal Push Rod:
http://www.classicperform.com/TechBo...ot.htm#pushrod

chevy_mike · 04-20-2017, 06:44 PM

Quote:

Originally Posted by The Rocknrod

Check Booster Pushrod Adjustment - Not Brake Pedal Push Rod:
http://www.classicperform.com/TechBo...ot.htm#pushrod

Yep, it doesn't take much to cause a problem. Tool is available on Amazon and I think even CPP sells it.

rvrfoot · 04-20-2017, 11:30 PM

I just got a set up for mine 66 c10. Going to install it this weekend.I will post pictures.I went to cpp thay told me a few things to do.

nail pounder · 04-20-2017, 11:43 PM

Does it have any adjustment? It's supposed to have some "free pedal" when you press the brakes before they engage, I think about ½". Without it, as the fluid gets hot it expands and applies the brakes. I had the same issue with my 58, I think I bought the master/booster from summit, anyhow, it has adjustment in the rod so a few minutes under the truck and problem solved. Also, don't overfill the master, fluid needs room to expand. Should be an easy fix.

sixty4bigwindow · 04-21-2017, 12:15 PM

Thank you guys for your input so far! I have neglected to mention that before I put the dual MC on and did the swap, I was running the stock MC with the power booster... So the shaft adjustment was made for that original modification. After everything you guys have said, it sounds like my first step is going to be to adjust that shaft. I will do that this weekend, and update with details.

And for nail pounder, I think I am running a bit high on the fluid in the reservoirs, both of them are at about 85% to the top. That is probably a bit high. How much do you guys run in your MC's? Thank you!

04-20-2017, 03:27 PM	#1
sixty4bigwindow Registered User Join Date: Feb 2016 Location: BACK in Southern Oregon... Don't ask Posts: 151	CPP front disc brake swap, brakes sticking and smoking a bit Ok so i finished doing the CPP front disk brake upgrade, bled the lines, fixed all the leaky spots. Went on a drive, and about 10 minutes in, it felt like my rig was slowing down and needed more gas pedal. Funny smell, knew it was the brakes when I pulled over and saw some smoke... i am running a combination valve and dual chamber MC from a 72 c10, mated to a power booster from a 77 c20 (i believe the model is correct, not quite sure,) and the stock pedal rod, with a modified bracket. After I let it sit for about am hour, the pedal went back to normal (it was super tight with no play during the issue.) I'm wondering if i need to get a shorter brake rod or just remove the booster completely? Figured Id come here first to see what you guys think! Thank you in advance guys!!

04-20-2017, 04:45 PM	#2
forestb Registered User Join Date: Jan 2009 Location: Burbank, CA Posts: 3,619	Re: CPP front disc brake swap, brakes sticking and smoking a bit I would try shortening the brake rod first. I had that same problem once.

04-20-2017, 05:15 PM	#3
Ben_Yeaton Registered User Join Date: May 2014 Location: Los Angeles, CA Posts: 141	Re: CPP front disc brake swap, brakes sticking and smoking a bit I had an issue where my brakes would lock up, almost feel like the truck was slipping. Turned out to be the booster plunger (rod) that engages with the master cylinder. It was too long, making the brakes engage even without a foot on the pedal. And then as it got warm, it got worse. I would start there as well.

04-20-2017, 06:28 PM	#4
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: CPP front disc brake swap, brakes sticking and smoking a bit Check Booster Pushrod Adjustment - Not Brake Pedal Push Rod: http://www.classicperform.com/TechBo...ot.htm#pushrod __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?

04-20-2017, 11:30 PM	#6
rvrfoot Registered User Join Date: Oct 2016 Location: san bernardino ca Posts: 1,611	Re: CPP front disc brake swap, brakes sticking and smoking a bit I just got a set up for mine 66 c10. Going to install it this weekend.I will post pictures.I went to cpp thay told me a few things to do.

04-20-2017, 11:43 PM	#7
nail pounder Registered User Join Date: Aug 2014 Location: Fallbrook CA Posts: 453	Re: CPP front disc brake swap, brakes sticking and smoking a bit Does it have any adjustment? It's supposed to have some "free pedal" when you press the brakes before they engage, I think about ½". Without it, as the fluid gets hot it expands and applies the brakes. I had the same issue with my 58, I think I bought the master/booster from summit, anyhow, it has adjustment in the rod so a few minutes under the truck and problem solved. Also, don't overfill the master, fluid needs room to expand. Should be an easy fix.

04-21-2017, 12:15 PM	#8
sixty4bigwindow Registered User Join Date: Feb 2016 Location: BACK in Southern Oregon... Don't ask Posts: 151	Re: CPP front disc brake swap, brakes sticking and smoking a bit Thank you guys for your input so far! I have neglected to mention that before I put the dual MC on and did the swap, I was running the stock MC with the power booster... So the shaft adjustment was made for that original modification. After everything you guys have said, it sounds like my first step is going to be to adjust that shaft. I will do that this weekend, and update with details. And for nail pounder, I think I am running a bit high on the fluid in the reservoirs, both of them are at about 85% to the top. That is probably a bit high. How much do you guys run in your MC's? Thank you!



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