Yet another master cylinder question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**slepysal** · 12-15-2008, 02:53 PM

Ok so I did do a search.....I wanted to install a dual circuit master cylinder on my 60. I have the slave cylinder worked out, so no problem there. I have a master cylinder off of a 70 Impala drum-drum,and need to get some reducers/adaptors (from royal brass ,thanks cheif)to fit the existing line ( that will feed the fronts) and new line that will tap into the rear.
I thought the hard lines that come of my original brake / clutch master were 3/16 ( 3/8 wrench), but no they are 1/4 " (7/16 wrench ). So I have to get and bend up some new lines.
This is were I'm confused ,will I run into any problems using bigger hard lines when I do my disc brake swap ? I wanted to install a dual feed master ( for drums ) now , and swap in the disc master cylinder when I do the disc swap . The porportioning valve that i got from CPP has a 1/4 rear port and 3/16 front ports, so can I just use an adaptor to use the 1/4 front line ?
I know this shouldnt be that hard so thanks in addvance .

**slepysal** · 12-15-2008, 07:51 PM

ok I called CPP ( thats who I got my prop valve from ) They said I could use an adaptor off of the prop valve to go from 3/16-1/4 .

protrash64 · 12-15-2008, 10:34 PM

I was told about this many years ago when I re-did my brakes. The tube size doesnt matter being that the system is hydrualic. I believe what CAN make a difference is the bore of the ms-cylinder and how the pedal is mechanically tied to the cylinder. On my 64 there are some different holes which could be used for adjustment (on the brake pedal mount).

**slepysal** · 12-16-2008, 01:16 AM

very cool . thanks protrash thats good to know. If I run no booster then the push rod attaches to the upper hole original location , if I run a booster then it attaches to the lowwer hole , or you drill a hole aprox 1" below the original hole.

**ChiefRocka** · 12-16-2008, 10:02 AM

Yeap...you'll be fine, Protrash is correct.

Hey Protrash...speaking of hydraulics ??

protrash64 · 12-16-2008, 12:19 PM

Damn slepysal, you know more about it than I do!!!

I just noticed the stuff on the pedal when I was doing some wiring!!! I know I had to do some creative reducing at the ms-cylinder also. Im running manual brakes, so I put some extra torque on my seat bolts

!

Im working on it John!!!! Work is slow as is income and Im looking for a new job. Im not in any financial crisis but slow and cautious is the way Im going.

**slepysal** · 12-16-2008, 04:21 PM

Great, I got the fittings now I have to wait for it to warm up !! At 40 degress it's to cold for this old man to work on his truck, hey what can I say 40 is FREEZING for us Bay Area guys.

12-15-2008, 02:53 PM	#1
slepysal Registered User Join Date: Oct 2006 Location: San Jose NOR*CAL Posts: 3,080	Yet another master cylinder question Ok so I did do a search.....I wanted to install a dual circuit master cylinder on my 60. I have the slave cylinder worked out, so no problem there. I have a master cylinder off of a 70 Impala drum-drum,and need to get some reducers/adaptors (from royal brass ,thanks cheif)to fit the existing line ( that will feed the fronts) and new line that will tap into the rear. I thought the hard lines that come of my original brake / clutch master were 3/16 ( 3/8 wrench), but no they are 1/4 " (7/16 wrench ). So I have to get and bend up some new lines. This is were I'm confused ,will I run into any problems using bigger hard lines when I do my disc brake swap ? I wanted to install a dual feed master ( for drums ) now , and swap in the disc master cylinder when I do the disc swap . The porportioning valve that i got from CPP has a 1/4 rear port and 3/16 front ports, so can I just use an adaptor to use the 1/4 front line ? I know this shouldnt be that hard so thanks in addvance . __________________ 1960 Apache long bed fleet L6 250 Clifford intake 2 bbl carb. Langdon cast headers with dual exhaust and bellflower tips. T-5 5 speed, power steering and power disc brakes. "Over, Around or through it... " Last edited by slepysal; 12-15-2008 at 06:18 PM.

12-15-2008, 07:51 PM	#2
slepysal Registered User Join Date: Oct 2006 Location: San Jose NOR*CAL Posts: 3,080	Re: Yet another master cylinder question ok I called CPP ( thats who I got my prop valve from ) They said I could use an adaptor off of the prop valve to go from 3/16-1/4 . __________________ 1960 Apache long bed fleet L6 250 Clifford intake 2 bbl carb. Langdon cast headers with dual exhaust and bellflower tips. T-5 5 speed, power steering and power disc brakes. "Over, Around or through it... "

12-15-2008, 10:34 PM	#3
protrash64 Resistance is Futile Join Date: Dec 2006 Location: Mesa,Arizona Posts: 3,520	Re: Yet another master cylinder question I was told about this many years ago when I re-did my brakes. The tube size doesnt matter being that the system is hydrualic. I believe what CAN make a difference is the bore of the ms-cylinder and how the pedal is mechanically tied to the cylinder. On my 64 there are some different holes which could be used for adjustment (on the brake pedal mount). __________________ 64 CHEVY PICK-UP > http://67-72chevytrucks.com/vboard/s...otrash+re-hash 64 CARRYALL >http://67-72chevytrucks.com/vboard/s...=1964+suburban 66 LB >http://67-72chevytrucks.com/vboard/s...d.php?t=427852 STRENGTH/DETERMINATION/MERCILESS/FOREVER .......posted via stationary device

12-16-2008, 01:16 AM	#4
slepysal Registered User Join Date: Oct 2006 Location: San Jose NOR*CAL Posts: 3,080	Re: Yet another master cylinder question very cool . thanks protrash thats good to know. If I run no booster then the push rod attaches to the upper hole original location , if I run a booster then it attaches to the lowwer hole , or you drill a hole aprox 1" below the original hole. __________________ 1960 Apache long bed fleet L6 250 Clifford intake 2 bbl carb. Langdon cast headers with dual exhaust and bellflower tips. T-5 5 speed, power steering and power disc brakes. "Over, Around or through it... " Last edited by slepysal; 12-17-2008 at 04:19 PM.

12-16-2008, 10:02 AM	#5
ChiefRocka Hollister, CA. Join Date: Sep 2006 Location: Hollister, Ca. Posts: 6,150	Re: Yet another master cylinder question Yeap...you'll be fine, Protrash is correct. Hey Protrash...speaking of hydraulics ?? __________________ John What the Heck is that ?? CURRENT BUILDS: 62 BurbMaster Other Builds: My '63 C-10,LWB,CC,BBW '06 HD StrAight Axle Swap Father/Son '67 C-20, LQ9,4L80,Bagged,8-Lugger !!Good Friend Richard's Build AMERICAN CUSTOMS & CLASSICS (831) 630-1965 www.ACCHOLLISTER.com ACC on FACEBOOK "Rest in Peace, Mom & Dad ... I will see you again someday!"

12-16-2008, 12:19 PM	#6
protrash64 Resistance is Futile Join Date: Dec 2006 Location: Mesa,Arizona Posts: 3,520	Re: Yet another master cylinder question Damn slepysal, you know more about it than I do!!! I just noticed the stuff on the pedal when I was doing some wiring!!! I know I had to do some creative reducing at the ms-cylinder also. Im running manual brakes, so I put some extra torque on my seat bolts! Im working on it John!!!! Work is slow as is income and Im looking for a new job. Im not in any financial crisis but slow and cautious is the way Im going. __________________ 64 CHEVY PICK-UP > http://67-72chevytrucks.com/vboard/s...otrash+re-hash 64 CARRYALL >http://67-72chevytrucks.com/vboard/s...=1964+suburban 66 LB >http://67-72chevytrucks.com/vboard/s...d.php?t=427852 STRENGTH/DETERMINATION/MERCILESS/FOREVER .......posted via stationary device

12-16-2008, 04:21 PM	#7
slepysal Registered User Join Date: Oct 2006 Location: San Jose NOR*CAL Posts: 3,080	Re: Yet another master cylinder question Great, I got the fittings now I have to wait for it to warm up !! At 40 degress it's to cold for this old man to work on his truck, hey what can I say 40 is FREEZING for us Bay Area guys. __________________ 1960 Apache long bed fleet L6 250 Clifford intake 2 bbl carb. Langdon cast headers with dual exhaust and bellflower tips. T-5 5 speed, power steering and power disc brakes. "Over, Around or through it... " Last edited by slepysal; 12-18-2008 at 12:27 PM.



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