64 K10 horizontal booster & master cylinder upgrade to mate with corp 10 bolt front

[pheengurs]

ok. I've spent alot of time trying to find specific answers and like all posts similar to this one, have come up short, trying to find what I need myself...

SO

lets ask for help shall we?


on my 64 k10 stepside, I have swapped in a 1987 corporate 10 bolt front axle. and now I need to get the brakes done.

I've figured out all the plumbing issues, and have the hoses lines and calipers, and even a disc/drum proportioning valve from a late 80's truck. However my issue is with the stock horizontal brake booster & associated bracketry and figuring out what to do about it, and what booster/master cylinder options will work.

to put things in a price perspective, the local napa price for a new booster & master cylinder of the 1987 year was around $150 or so.

now I've got those parts in the garage, and its quite obvious the booster won't work. too large diameter, too long bracketry, and 6 bolts to redrill = not cool, too much work to fab to get working, and I don't have the time nor do I want to risk my safety...

so here's a direct question: can I use the stock 64, horizontal power brake booster with a 1987 or different year disc/drum master cylinder?

will it bolt onto the old booster? (I should be able to check out if the 1987) tomorrow)

and the rod between the booster and the master cylinder? how does one know/determine what length its supposed to be?

will the stock booster be able to provide enough 'boost' to run newer 1987 front disc brakes?


how does that all work? how do I know what 'bore' length? or is that something else?

I know there are a HUGE pile of posts on upgrading to disc brakes...I've read a ton of them. few mention specific issues/problems with mating the brake pedal to the booster and the booster to the master cylinder -- which is where I'm at.

has anyone done this? can you provide details on how did you get it all to work?

I have some pics of my current stock 64 power brake setup that I can post up later if that'll help, however there is a post that already shows the horizontal setup -- http://67-72chevytrucks.com/vboard/s....php?p=2954872 -- and touches on what I'm talking about but not specifically .. so any help is MUCH MUCH APPRECIATED!

[duallyjams]

Happy reading
http://www.67-72chevytrucks.com/vboa...=1#post3257836

[pheengurs]

yes I've already read that one, all three pages of it... a great idea, and superb to see products specifically designed for the era, however nothing in that post answers my questions, that I've posted here.

it explains how to use straight through booster & master cylinder combos, and how they work super great with that sixty dollar steel bracket.

I've done many searches, many different ways. on many forums and search engines. I've sifted through reams of information, and come up short.

my question is regarding the stock horizontally mounted booster, and whether or not it will work with more modern master cylinders, or anything newer than 1971?
AND will that booster have enough 'boost' to run front disc brakes designed for a much larger 1987 booster?
AND what is all this stuff about bore size? and rod length? is there anyway to change to a disc/drum master cylinder on the stock booster without having to mess with the pedal rod length and the booster to master cylinder rod length?

here's a couple pics of the setup I've got...

[pheengurs]

the above pics were one of my truck in its natural environment -- meaning it's a 4wd that gets used as a 4wd...

and the second is of the 1987 corporate 10 bolt front diff that I've installed under there as of just a few days ago... it is the source of the brake upgrades, and why I bought all this 1987 brake hardware / booster / master cylinder...

and why I've ended up reading so much info online, trying to find a way to make this stuff work...

I've given up on using the 1987 booster, it's too big, and too different.

What I want to do is swap the new 87 booster with a new 64-66 booster, and mate it up with a disc/drum master cylinder to power those 1987 brake calipers on that front axle...

again, any info/advice/insight you can provide is greatly appreciated!


here's the pics of what I have currently:

[64fleetside]

I have an original '64-66 booster using a 1980's C10 master, works fine. Mine's 2wd drive, '71-87 discs up front, reg '71 drums on rear.

[pheengurs]

64fleetside, is your 80's C10 master cylinder the all metal kind or the kind with the plastic resovoir? is it an early 80's master cylinder? feel free to post a pic of your setup here...

how did you get them to mate up?
did you have to mess with the rod between the booster and the master cylinder?
do you have that same horizontal bracket, too?

the master cylinder that's stock for 1987 setup that I bought to match the corp 10 axle & brakes is a plastic kind. I just checked the rear of it, that's supposed to go into the front of the booster -- and it definitely won't fit on the stock 1964 booster. I compared the ends and not only is the diameter of the 'bore'??? too large, but the depth of the 'bore'??? is too shallow.

in the post I quoted earlier, Joe321 said he's got a master cylinder from a 1971 and a booster from a 66. But no further details...

[64fleetside]

I used one from early 80s, an all-metal master. IIRC it fits C10 '71-80 or so, fits fine.


http://s210.photobucket.com/albums/b...rrent=1a6e.jpg

[pheengurs]

thanks for the pic, that helps!

I did some more reading on brake parts in general, and found explanations of master cylinder bores...not what I thought they were, obviously... the bore is inside the cylinder, has nothing to do with the diameter of the rear of the mounting flange... ok. good to know! of course, no parts place that I know of, ever measures that, so I'm still ordering parts and hoping they mate...

well, I hope to pick up my parts at napa today. I went with a new 64 booster, and a new 71 master cylinder.

hopefully they mate up without having to screw around with rod adjustments.

I think I'll take the opportunity while the booster is off, to give that oddball horizontal bracket a shot of paint, too...

here's another question for you all:

where do you have your brake booster vacuum lines connected to? back of the carb, or directly off the intake manifold???

mine's off the back of the carb, and I find it rather annoying when working on the truck because of the steel tubing and fitting required to bolt solidly onto the back of the carb... that tube always gets bent this way and that because it's in the way... I end up having to replace it every other year. a couple options would be to replace the tube with some kind of adaptor fitting so I can simply run rubber hose between the carb and booster...or block off the carb port, and run the booster from manifold vacuum...

what say ya'll?

[64fleetside]

I don't think it really matters-on the two barrel truck, it has the booster plumbed into the intake, the QJ truck has it off the back of carb.

[Clyde65]

I would measure the original master where the rod goes into it, then measure a new master and that will tell you if it will work or not, might need a micrometer, most truck masters are 1" or 1.125" I believe. Corvette dual masters are also very popular.

[pheengurs]

well, I installed the new booster and m/c, then found out my ideas about where I was gonna mount the prop valve wasn't going to work, nor did the fittings I bought turn out to be the size I need, and I seem to be missing the little adaptors for my double flare maker, so, I just gave up until I can hit a parts store... I'll post a pic up soon...

Originally Posted by 64fleetside

I don't think it really matters-on the two barrel truck, it has the booster plumbed into the intake, the QJ truck has it off the back of carb.

mine is not original. I've got a 355 cu in, mild cam, edelbrock air gap intake, edelbrock carb, plumbed to a snorkel setup...

over the years, I think I've tried running the brake booster from either ports, but always seem to end up using the carb port. just wondering what other folks have setup...

Originally Posted by Clyde65

I would measure the original master where the rod goes into it, then measure a new master and that will tell you if it will work or not, might need a micrometer, most truck masters are 1" or 1.125" I believe. Corvette dual masters are also very popular.

I did some eyeball measuring with an awl, stuck into the end of the new m/c and marked it with my thumb, then compared it to the same spot on the old m/c, and thought there was about less than 1/8 difference...

now that was obviously not the most scientific of measurements ;-)

what would 1/8 of an inch or less mean, as far as braking goes?

the tip of the 64 booster, appears to be adjustable, so I could pull the booster & m/c apart again...

[pheengurs]

ok, as promised, here's a pic of the 66 booster installed with the 71 master cylinder...

any answers to the following:

what happens to braking if say the rod between the m/c and booster is less than 1/8" short?

where do you guys have your brake booster vac line connected? (carb or intake vac port?)

edit ---> nevermind re manifold vacuum -- realized edelbrock rear port is manifold vacuum as it's below the plates...thank you google!

still looking for rod info tho...

[Captainfab]

If the pushrod between the booster and the master is short, you may see longer pedal travel, than if it were the correct length.

[duallyjams]

Some rod are adjustable you definitely do not want any play in it. looks good.

[pheengurs]

longer travel. ok, that makes sense. well, I guess I will unbolt the MC and take some exact measurements.

funny how (for me) some things that are logical and obvious, require confirmation that 'this is so'...

anyway, yeah, the new booster is exactly like the old booster, and it appears the little tip is adjustable....so after I measure the depth of the hole in the rear of the m/c + how deep it goes into the booster vs the actual rod length, and see if I'm out at all...

I suppose a guy could also adjust the push rod by feel...adjust it out so that you cannot bolt on the m/c without resistance, and then back off the rod adjustments until you feel no resistance...

it'll be done this weekend. I plumbed up the front lines to & from the prop valve. one more line to mate up with the rear line from the prop valve, and then shortening some coiled lines I grabbed from a junkyard to connect between the prop valve and the m/c... then I can bleed the brakes and test the pedal feel...

thanks for the help guys! I'll post up that rod measurement just in case someone may need it in the future...

[duallyjams]

post some pics of your plumbing skills

[pheengurs]

certainly, but it ain't gonna be pretty lookin like most of the pics I've seen!

I'll post a couple more pics on the weekend...

I appreciate all the help you guys have given and to the operators of the forum, and especially it's search functions, as though I didn't learn everything I needed via search, I did learn ALOT, and continue to do so on every topic I look up...so thanks!



I've never revamped an entire brake system in one shot before.. Also first time using double flare tool -- I'm hoping my flares will not leak! Many of the bends are by hand. I have a simple bending tool, but it's useless when you need tight bends in tight areas, which is basically my entire brake line setup!

The last guy who owned the truck (or whomever!) plumbed nearly all the brakelines about as close to the exhaust as possible. I wanted to avoid that stupid mistake, so I have gone out of my way to keep the lines cooler than they've ever been on that truck...

copying as best I could newer model chev's (80's) I ran the front brake lines forward in the engine bay from the prop valve.

driver front side bends down and back along the inside of the frame, to connect to the driver brake hose. passenger front goes to the same point forward, then down and across the frame support under the radiator, then back inside the frame towards the pass brake hose.

the rear line heads out and down towards the firewall from the prop valve, avoiding wiring harnesses and the steering column, as well as the exhaust, where it bends back and down and across the manual transmission cross-member. from there, it runs inside the frame again, all the way to the rear axle and it's single brake hose, which t's off to both rear brakes.. I replaced the lines from as close to the rear brake hose, as possible, but basically it's stock routing, but 3/16 line instead of 1/4.

anyway, I plumbed up the rear line last night to the prop valve, and finished the 2 lines from m/c to prop valve. I also realized I needed to remount my prop valve from being solid on the fender, to hanging somewhat freely (like most guy's setup)... otherwise, what's the point of the coils & extra bends to keep vibration from killing your lines, right? So I will cut up some bar stock, put it in the vice, do some bending and shaping and a little paint for a mount, that will be in basically the same spot underneath the m/c.

I also adjusted the vac booster pushrod outward about 1 full turn from it's factory position. I of course, totally forgot to measure it with the digi-caliper... but it's only two bolts to get the mc off, so no biggie... I'll post up a figure after I've bled and test driven the brakes just to be sure I post a number that actually works...


here's one more question for you all:

because my truck sees alot of water and mud, is there any harm or benefit to running RTV along the seam between the m/c and booster???
the old one had some buildup in this area -- everything worked, but it was there none the less...perhaps rtv would keep it clean?

[joe231]

I'm sorry that I'm late to the party.....
looks like you got it figured out,

[pheengurs]

hey no worries... I've responded to posts years old if it was open ended...

so I have all the brake lines, connections, joins hoses and everything all plumbed up. I had alot of problems with leaking connections..not only with all three of the flares I made, but with store bought lines & brass fittings/connections... It's the rear lines that are giving me the most trouble. But also the lines from the m/c to the prop valve, and then out the rear of the prop valve...

can someone tell me why & have different sized m/c & prop valve connections between them & also different size for rear line? WTF??? why isn't the entire system ALL 1/4 or ALL 3/16? Right now I have around 5 different sizes between the m/c, prop valve, and rear line...

anyway, I've bench bled the m/c, I've individually bled each brake, starting from the brake farthest from the m/c.

and have just finally sorted out a huge pile of other problems and finally have all four tires on the ground... lemme tell you, a front axle swap that includes a disc brake upgrade may seem easy on paper, even to a novice, but in reality is VERY difficult, at least when you're upgrading from the 60's to the 80's !!!

I'm shy of pics right now. I'll take some today for sure and post em up soon. I'm very much hoping to have this truck on the road today...