1964 4wd 3/4t - Power brake upgrade

[Skywalker1210]

Hey there,

I am looking into upgrading the brakes on my 64 K20, mainly the power brake booster and master cylinder.

I tried to locate the parts with the usual suspects (LMC, etc.), but so far, no one knew what I needed. All the sets they are offering are for c20, RWD.

Any ideas? Originally, I was also hoping to convert to a 2-way system. But I gave up, since the first challenge is finding the right booster/cylinder.

Thanks and regards from Switzerland
Luke

[LT1 Burb]

You can use the 67-72 power brake and master cylinder assembly from Early Classic Enterprises, that is what I used on my suburban and I converted to a 2 line system.

[Skywalker1210]

Originally Posted by LT1 Burb

You can use the 67-72 power brake and master cylinder assembly from Early Classic Enterprises, that is what I used on my suburban and I converted to a 2 line system.

Thanks! Complicated conversion? Especially bracket and connection to the pedal?

[60-66]

The stock power brake booster is the same from C10 C20 C30 to K10 and K20 . You can also bolt on any double master cylinder from like a 67-72 drum or disc truck or your stock manual master cylinder. Heres a 65 K20 with the stock power brake booster .

[The Rocknrod]

What color is that engine?

Originally Posted by 60-66

...

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[60-66]

Originally Posted by The Rocknrod

What color is that engine?

Gray , stock 1965 283.

[LT1 Burb]

Originally Posted by Skywalker1210

Thanks! Complicated conversion? Especially bracket and connection to the pedal?

No, it's pretty well a bolt in conversion.

[Captainfab]

I make these brake booster brackets.

http://www.67-72chevytrucks.com/vboa...d.php?t=339081

I don't normally supply the booster and master, but since you are in Switzerland and can not buy them locally, I can help with the booster and master as well.

[Skywalker1210]

Thanks very much.

So far, the booster was completely different and located nearer to the front of the hood:

The problem is space. The booster/master cylinder assembly I already bought are way too big - the air filter is in the way. I need to get a smaller one, I guess. Just not sure which one would fit, i.e. which diameter I need for the 1bbl carb.

But I would try to do that with that bracket. I will make some more pictures and will post them later.

Thanks!

[60-66]

That's the Hydrovac system. I have one on a 1963 and I don't like it. When you ordered the factory power brake booster on a 6 cylinder you automatically got a smaller oil bath air cleaner like this one.

[Skywalker1210]

Originally Posted by 60-66

That's the Hydrovac system. I have one on a 1963 and I don't like it. When you ordered the factory power brake booster on a 6 cylinder you automatically got a smaller oil bath air cleaner like this one.

Great - thanks for the info. Any idea what I can use instead? I don't know the diameter / which air cleaner could fit.

Here's how mine looks like...

[Skywalker1210]

Need some more help please!

So, I installed the new brake booster with the bracket from Captainfab (great product BTW, thanks!). Fits perfectly.

But the push rod (connection to brake paddle) is WAY too short. I am missing about 4 inches. Any experience what I should use to close the gap?

Thanks in advance
Luke

[The Rocknrod]

Most people fabricate one or you can buy one on ebay and do the adjustment on it (to length).
This is some info, same thread just broke out for ease of viewing:
http://67-72chevytrucks.com/vboard/s...&postcount=342
http://67-72chevytrucks.com/vboard/s...&postcount=343

[Skywalker1210]

Thanks! Helpful indeed.

Just ordered a universal kit from SummitRacing. Let's see if that works...

[pwrbrkpadguy]

Once you do this modification you more than likely will experience a limp top third pedal and then hold on it will stop great. The cure is converting from the 6 to 1 pedal ratio of the manual brake system to the 4 to 1 ratio of the power system. The correction requires drilling a 3/8 hole 1" center to center below the original hole and relocating the push rod. Once this is done, balance the brake adjustment at the shoes front and rear and you will have very good brakes without locking the rear down until you need them!

[Skywalker1210]

Thank you pwrbrkpadguy.

Does this also apply/is needed when I had a hydrovac power brake system installed?

[pwrbrkpadguy]

I knew you were gonna ask me something I'm not sure about! I think it does but don't base your brakes on thinking. There are some REAL experts on here maybe someone will chime in.

[Captainfab]

I would suggest taking a look at your pedal to see if there are 2 holes. One would be where your original pushrod was connected. If in doubt, measure your current pedal ratio.

[The Rocknrod]

Pedal Ration Explanation:
http://www.mpbrakes.com/techtalk/how...ng-pedal-ratio