Brakes from 73-87 pickups.

[edwardgonzalez]

So work has finally begun on the 71 pickup I purchased last year for $500. I needs a lot of work it has been sitting for a long time. It looks like the brake system is my next step. It currently is disc in the front and drum in the rear. I pulled the top off of the master cylinder and it was dry and full of rust. I'm thinking I may have to change everything. I want to save some money and upgrade to power brakes also. what is my best route? Can I pull the booster, master cylinder, and proportion valve off of a 73-87 pickup? they seem to be the most readily available. will I still keep the hoses from the 71 system? how hard of a swap is this? what should I know before tackling this conversion? I know I'm asking a lot of questions but I want to know as much as I can about this before starting. Any help will be greatly appreciated, thank you.

[Overdriven]

http://67-72chevytrucks.com/vboard/s...d.php?t=444815

Has a bunch of info. Basically, the ball joints must match the spindles being used. Tie rod lengths also differ, not entirely sure you can use 73-87 tie rods and center link on a 67-72. If you can get the entire crossmember from the 73-87 that is apparantly the way to go as then everything will be 73-87.

[edwardgonzalez]

I'm confused. I already have disc brakes in front. If I get the booster, master cylinder, proportion valve, and lines from a 73-87 pickup I would still have to change all of that other stuff also? I was hoping to just get those things for my truck. I didn't want to have to change my whole suspension.

[67 chevelle]

Originally Posted by edwardgonzalez

I'm confused. I already have disc brakes in front. If I get the booster, master cylinder, proportion valve, and lines from a 73-87 pickup I would still have to change all of that other stuff also? I was hoping to just get those things for my truck. I didn't want to have to change my whole suspension.

You dont have to , those year trucks braking system , booster master and combo valve should be fine

[edwardgonzalez]

Cool. How hard will the mounting of the booster to my firewall be? Will it just got in? Do I use the rod from my current mater cylinder?

[BILT4ME]

It will bolt directly on.

Use the rod from the master cylinder that comes with the booster. (They MAY be the same, but I'm not sure.) you will need to adjust it because firewalls may vary in thickness and pedal travel.

I bolted in a Power booster and MC from a 1975 3/4 ton and pulled the complete front axle as well with discs. I also installed a 1979 12 bolt rear axle. All the brakes worked fine because all the piston sizes were the same.

If you want to research it yourself, dig into the replacement parts at a local parts store and find out what the piston diameters are for each year (MC, Disc Calipers, Rear Wheel Cylinders) and see if they match. If so, then there will be no difference in braking. It's all about the VOLUME of fluid pushed each time you step on the pedal.

[edwardgonzalez]

Will the brake lines connect with the hoses from the 71 system. Or would I have to Change the hose to a different year's hose. Can I use my original caliper?

[BILT4ME]

I would pull the brake lines from the donor vehicle, at least from the MC down to the first junction block on the front crossmember.

i am not sure if the lines will directly connect from your current booster or not. I am guessing they WILL.

Also take the hose and check valve for the booster from the donor if you can. You may need to get a new grommet to keep it sealed.

GM did not start using metric until the 1990's.

[old Chevy guy]

if you just want to change the master and brake booster there's no need to change to a newer setup, the booster and master for a 71 is still readily available. I just replaced both on my 71 this past spring.

[edwardgonzalez]

I went to the parts store and yes they have the booster and master but not the proportion valve. Could I buy the booster and master for the 71 and use the proportion valve and lines from a 73-87 truck?

[BILT4ME]

Can your existing proportioning valve be rebuilt? I have done a lot of brakes on Chevy's, but have just realized I have never replaced nor rebuilt a proportioning valve.

Again, I would look at the caliper/wheel cylinder sizes of the 71 and compare them to the 73-87 version. If they are the same, then, yes I would use the proportioning valve from a later model. It's about equal fluid transfer.

[BILT4ME]

You can also install a MANUALLY adjustable proportioning valve that you could play with until it's set perfectly for your driving / hauling style. You can get those through Summit Racing.

[edwardgonzalez]

So I went to the junkyard yesterday and pulled a booster, master cylinder, proportion valve, and front steel lines from an 85 suburban. The only thing I could not pull was the line going to the rear. Everything looks to be in great shape. There were no leaks in any of the lines and the master cylinder was bone dry. I'm pretty happy with everything. I bought it all for $25. Do you guys know of any reasons this would not work on my 71 pickup? Will the rod from the booster work? Will the length of the rod be correct? Will I have to do any modifications to mount the booster?

[BILT4ME]

If there were no leaks in any of the lines and the MC was bone dry, there is a chance that the MC is bad. As I look at the pic you have of the booster, I see a MC that has been wet with brake fluid, possibly where the reservoir attaches to the MC.

Pull the check valve out of the front of the booster and tip it up to see if any fluid runs out of the booster housing. If so, it's bad.

Yes, the rod will need adjustment.

Will it bolt up: I believe it will.

Good luck!

[edwardgonzalez]

I should have explained better. When I said bone dry I meant outside. Inside the fluid was at level and very clean. It got wet when I removed the lines to pull it out. That was my bad. What kind of adjustment will the rod need?

[Deer_hunter_088]

following, might need to replace everything on mine sooooooooooo.

[BILT4ME]

There is a given amount of "freeplay" that the rod should have based on pedal travel before it touches the piston in the MC.

However, you want to make sure that the difference in throw of this MC will get a full stroke when installed on the firewall of the 71, before the pedal bottoms out.

Follow the specs for the brakes of the DONOR vehicle for rod adjustment.

[edwardgonzalez]

So I pulled the old master cylinder from the firewall and when I unhooked the brake lines from it I noticed there was brake fluid in the lines. And to my surprise the fluid was actually very clean. Doesn't look like there was any rust or anything. It's very exciting for me. I was planning on using all of the lines from the 73-87 brake system. Knowing now that I can use the lines on the truck makes things a little easier. My question is this. The proportion valve currently on my 71 has a line that t's and distributes to the front wheels from that T. And another line that goes to the rear. The proportion valve that comes with my booster/master combo has three lines coming from it. One that goes to the rear and two individual lines that go to wheels directly, no T. Can I Use a T to connect those two front lines and then run a line to the already existing T that distributes the lines to the wheels? For me that would be a cleaner install and easier than bending a bunch of lines.

[edwardgonzalez]

So I think my previous post may have confused some people. Maybe that's why no one respond, maybe it was just a dumb question. But if it was confusing I drew a picture that will hopefully clear it up. I drew it on paper so please excuse the drawing, I'm not very good. My question is about the highlited "T". Would that work?

[edwardgonzalez]

Here's another

[edwardgonzalez]

And another. Sorry I don't know why it's sideways

[RodnRudy]

You don't need the first T in your drawing. Go to the auto parts store and get a 3/8 24 inverted flare plug and plug one of the front brake line holes on the proportioning valve. Then run the other front brake line to the lower T fitting. That will feed both sides on the front brakes.

[edwardgonzalez]

Awesome. That sounds so much easier, thank you