Which Master Cyl To Use? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

S-31 · 05-25-2010, 11:01 PM

Im sure this has been asked and answered before and i've done a search and can't find a specific answer. I'm changing my 63 to disc brakes up front, but dont want power brakes, just a manual disc/drum setup. What master cylinder and proportioning valve are you guys using for that? Can a master cyl from a later model (73-87) truck with power brakes be used without the booster? Thanks

markeb01 · 05-25-2010, 11:28 PM

When I swapped a 1975 suspension in my 1960 GMC a number of years ago, I didn't use a booster, just the master cylinder and combination valve from the 75. After a couple of years (and a couple of panic stops) I could no longer handle the lower back pain associated with how much pressure was needed to stop the truck, so I added a power booster. I changed the master cylinder when I added the booster, but don't remember if it was required or not.

Years earlier I had a Chevelle, and there was a difference between M/C with and without a booster. The cup in the back of one was deep, and the other was shallow. I found out the hard way by installing the wrong one, and the brakes worked like an on/off switch with no modulation at all. Easy enough to check, just look up the listings for manual or power master cylinders at any online site like Napa or Schucks, and see if it's the same part number with our without a booster.

michaudracing · 05-25-2010, 11:49 PM

I used front discs from a '74 on my '63 Chevy. I simply used a '74 half ton manual master cylinder (the power master cylinder is different). I chucked the '74 proportioning/distribution valve and used a Wilwood adjustable proportioning valve. I still have the stock drums on the rear. I'm pleased with the master cylinder. Pedal pressure required is lower than the stock all-drum setup.

-Steve

raycow · 05-25-2010, 11:51 PM

In addition to the pushrod socket depth issue, sometimes the manual cylinder will have a smaller bore diameter. This will somewhat reduce the pedal effort required, at the expense of increased pedal travel.

Ray

Tx Firefighter · 05-26-2010, 08:43 AM

I'm running an 80 model manual master cylinder on my truck. I have several power boosters under my workbench but have never felt any desire to mess with installing one. The pedal effort is very comfortable running manual setup.

S-31 · 05-26-2010, 10:03 PM

Thanks for all the help guys. Thats gonna save me a lot of time and money.

05-25-2010, 11:01 PM	#1
S-31 Registered User Join Date: Mar 2010 Location: Fayetteville NC Posts: 98	Which Master Cyl To Use? Im sure this has been asked and answered before and i've done a search and can't find a specific answer. I'm changing my 63 to disc brakes up front, but dont want power brakes, just a manual disc/drum setup. What master cylinder and proportioning valve are you guys using for that? Can a master cyl from a later model (73-87) truck with power brakes be used without the booster? Thanks Last edited by S-31; 05-25-2010 at 11:17 PM.

05-25-2010, 11:28 PM	#2
markeb01 Senior Enthusiast Join Date: Feb 2007 Location: Spokane Valley, WA Posts: 8,356	Re: Which Master Cyl To Use? When I swapped a 1975 suspension in my 1960 GMC a number of years ago, I didn't use a booster, just the master cylinder and combination valve from the 75. After a couple of years (and a couple of panic stops) I could no longer handle the lower back pain associated with how much pressure was needed to stop the truck, so I added a power booster. I changed the master cylinder when I added the booster, but don't remember if it was required or not. Years earlier I had a Chevelle, and there was a difference between M/C with and without a booster. The cup in the back of one was deep, and the other was shallow. I found out the hard way by installing the wrong one, and the brakes worked like an on/off switch with no modulation at all. Easy enough to check, just look up the listings for manual or power master cylinders at any online site like Napa or Schucks, and see if it's the same part number with our without a booster. __________________ My Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=444502 Last edited by markeb01; 05-25-2010 at 11:30 PM.

05-25-2010, 11:49 PM	#3
michaudracing Registered User Join Date: Nov 2008 Location: Atlanta, GA Posts: 5	Re: Which Master Cyl To Use? I used front discs from a '74 on my '63 Chevy. I simply used a '74 half ton manual master cylinder (the power master cylinder is different). I chucked the '74 proportioning/distribution valve and used a Wilwood adjustable proportioning valve. I still have the stock drums on the rear. I'm pleased with the master cylinder. Pedal pressure required is lower than the stock all-drum setup. -Steve

05-25-2010, 11:51 PM	#4
raycow Registered User Join Date: Mar 2003 Location: San Francisco, CA USA Posts: 2,454	Re: Which Master Cyl To Use? In addition to the pushrod socket depth issue, sometimes the manual cylinder will have a smaller bore diameter. This will somewhat reduce the pedal effort required, at the expense of increased pedal travel. Ray

05-26-2010, 08:43 AM	#5
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: Which Master Cyl To Use? I'm running an 80 model manual master cylinder on my truck. I have several power boosters under my workbench but have never felt any desire to mess with installing one. The pedal effort is very comfortable running manual setup. __________________ I'm on the Instagram- @Gearhead_Kevin

05-26-2010, 10:03 PM	#6
S-31 Registered User Join Date: Mar 2010 Location: Fayetteville NC Posts: 98	Re: Which Master Cyl To Use? Thanks for all the help guys. Thats gonna save me a lot of time and money. Last edited by S-31; 05-26-2010 at 10:05 PM.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.