1963 versus 1964 Power Brake Booster

[rexcrews]

Guys,

May I appeal to your knowledge about a brake booster fitment question.  I have a '64 Riviera and a '63 Invicta, and the booster on my '63 Invicta is failing.  I thought the booster would be identical to my Riviera, but the vacuum lines on the '63 attach to the top of the can in a Y sort of fitting; on the Riviera, the lines are on the front of the can.  Are these booster interchangeable?  Most sources I have found list 1961-2 and 1964-6, but leave out the '62 models.  I am also guessing, perhaps incorrectly, that the Rivera booster is the same as other full-size Buicks for '63-'64.

 

Is it possible that an early '63 car would have a '62 style booster?  I am just confused and want to make sure my '63 has the right booster.  Thanks! Rex

[TexRiv_63]

Not sure about 64 but in 63 they used two different types of booster, the one used affected a number of things.

[RivNut]

In 63, a hose came from the booster to a vacuum storae canister. Not needed in 64.

[rexcrews]

Thanks, guys. You have helped a lot.  Rex

[XframeFX]

On 2/5/2023 at 3:03 PM, TexRiv_63 said:

Not sure about 64 but in 63 they used two different types of booster, the one used affected a number of things.

My shop manuals are not handy at the moment to research what failure modes may exist for the 1963 Riviera Power Brake Booster.

Two types? I have only seen one in all the 1963 Rivieras I've encountered, Moraine type I believe.

 

I noticed no reserve assists as part of chasing vacuum leaks. So, I had it rebuilt after 1st replacing hoses and testing accumulator vessel and check valve.

Upon re-installation, I noticed the same situation exists, zero reserve. All vacuum gone immediately after shutdown. I was going to follow-up but got occupied with numerous other Riviera issues.

I'm now thinking to cut towards another booster for the 1964-65 Riviera. Unlike 1963, rebuilt replacements are supported or, was. I see no stock anywhere.

 

- What other GMs use the 1964-65 Power Brake Booster?

- Are the long Master Cyl pushrod and pedal link interchangable with the '63?

- If interchange is incompatible, any tips on DIYing my rebuilt 1963 power booster? What could be causing the leak internally?

 

I am aware of brake light switch and not concerned.

Thanks!

 

[EmTee]

Are you sure the booster is leaking?  It's easy enough to test.  Do you have a Mity-Vac?

 

[1965rivgs]

I would guess the '64 booster is a bolt in replacement for the '63. Be observant of pushrod length as you want to be sure the pushrod length allows complete release of the master cylinder in any combination. Also, you will need to use a gasket between the master cylinder and booster when using the '63 booster.

Tom Mooney

[Jim Cannon]

I agree with Tom. Confirm that the "square o-ring" is in place on the neck of the '63 Master Cylinder, where it slides into the booster, and that it is sealing well. Later MCs have the groove for this o-ring but do not require the seal like '63.

 

The '63 uses external vacuum storage for reserve (the big can on the inner fender). Later years have the vacuum storage internal. Pretty easy to confirm the can does not have a leak.

 

If your '63 brake pedal holds some pressure on the MC input, it will quickly bleed off your vacuum reserve. Make sure the pedal retracts freely.

 

[XframeFX]

2 hours ago, 1965rivgs said:

Also, you will need to use a gasket between the master cylinder and booster when using the '63 booster.

Ah, I recall that O-Ring requirement. I definitely do not have a gasket in place for the original master cylinder.

 

I remember pulling up on the pedal before shutting down after brake bleeding process. It was up all the way and still, residule vacuum all gone.

 

Easy to check, two nuts, thanks. Will re-install with RTV sealant after inspection.

[1965rivgs]

3 hours ago, Jim Cannon said:

I agree with Tom. Confirm that the "square o-ring" is in place on the neck of the '63 Master Cylinder, where it slides into the booster, and that it is sealing well. Later MCs have the groove for this o-ring but do not require the seal like '63.

 

The '63 uses external vacuum storage for reserve (the big can on the inner fender). Later years have the vacuum storage internal. Pretty easy to confirm the can does not have a leak.

 

If your '63 brake pedal holds some pressure on the MC input, it will quickly bleed off your vacuum reserve. Make sure the pedal retracts freely.

 

  Later boosters have a seal in the face of the booster

Tom

[XframeFX]

7 hours ago, 1965rivgs said:

Later boosters have a seal in the face of the booster

Yes, I'm aware Tom, thanks.

If my power booster rebuild was botched, I'm inclined to dump it and switch to the newer version not just for vacuum tank elimination but for a fresh check-valve and that seal. 

Simply, an improved unit if I am successful in locating one

 

I'm certain I have that O-Ring on the Master Cylinder. But if missing, an easy fix.

[XframeFX]

On 1/26/2024 at 7:35 AM, Jim Cannon said:

I agree with Tom. Confirm that the "square o-ring" is in place on the neck of the '63 Master Cylinder, where it slides into the booster

Finally got around to removing that Master Cylinder on the 1963 Power Booster. It was a snug fit and the square profile O-Ring was in-place with Vacuum grease smeared around it. I cannot see how there's a leak there.

So, there must be a massive leak inside somewhere. Any tips?

 

Shop Manual stresses not to pinch diaphragm bead when twisting both housing halves to locked position.

 

 

 

 

 

 

Edited February 6 by XframeFX (see edit history)

[XframeFX]

On 1/26/2024 at 7:19 AM, 1965rivgs said:

I would guess the '64 booster is a bolt in replacement for the '63.

The Master Cylinder is back on the power booster and the seal scrutinized, definitely no leak there.

I isolated the Power Booster from the tank and check valve. Pumping frantically on my Mity-Vac, I can produce a few inches of vacuum. When I stop, it plunges down to Zero immediately, a massive Leak.

 

More on the Bendix power booster. I found a 10-year old post where a member was informed by Booster Dewey to use the 1964 - 66 Power Boosters as many 1963 Units are rebuilt incorrectly. I wish I knew this before I had my '63 unit rebuilt! He charged me plenty and returned it painted black.

 

Also, a 1964-66 power booster would include an integral check valve and no unsightly accumulator tank with the dent for 4-note horns I do not have. I am now looking to source this superior unit to replace that incompetent rebuild. Rockauto forever sold-out. MBM below?

 

 

 

 

Edited March 13 by XframeFX (see edit history)

[EmTee]

8 hours ago, XframeFX said:

When I stop, it plunges down to Zero immediately, a massive Leak.

I think you're now over the target... 

[XframeFX]

A heads-up on 1st generation power brakes. Not only did the 1963 Riviera miss out by 1-year on the good ST400 but also the Power Booster and master cylinder.

Of course after my botched rebuild, I now know the path I should've taken. Typical Riviera luck, need to address the same issue 3 times and more wasted $$$!

 

I dropped into a local Brake & Clutch shop who is a Dealer for https://mbmbrakes.com/gm-1964-1966-9-single-diaphragm-delco-style/

The counter person spent a great deal of time with me explaining most everything on the top end of the Brake system, much appreciated! Yes, they can rebuild Bendix, Delco-Moraine, Treadle-Vac or sell me a new MBM Unit.

He too agrees the Bendix Multi-Vac can be rebuilt incorrectly and if it needs rebuilding, better to switch to the Delco-Moraine unless originality is important.

He explained many details regarding the swap for pushrods and master cylinder compatibility.

Also, I now regret re-sleeving my master cylinder with the inferior cap & wingnut in the center.

 

• The Bendix Unit has a floating control valve at vacuum source. The reason there's an external vacuum reservoir.
• The Delco-Moraine Unit keeps vacuum on both sides of the diaphragm until the brakes are applied. When they are applied, obviously air is rushed-in to one side but he went into great detail on feathering of the pedal and kind of lost me.
• I've noticed accordion diaphragms under the caps of many single and dual circuit master cylinder caps. Easy to understand it expands when the reservoir level drops while not permitting the fluid to be exposed to more moisture laded air. However, that diaphragm is not possible in the '63 cap with that wingnut down the center! There is a "mini-cap" under the wing nut in an attempt to shield the vent.
• Older master cylinders have a denser body (higher pressure casting) and have a better chance of success when machining.
• After-Market Power Boosters that look OE with even "Moraine" in the stamping, cannot be rebuilt.

 

I encountered another helpful Parts Counter Person at Cummins this week. Extra effort to bring a specialty tool from Service to examine for duplication.

 

Brick & Mortar businesses and Cash & Carry still far better than online resources!

 

!964 Power Booster and Master Cylinder:

 

 

 

Edited March 16 by XframeFX (see edit history)

[EmTee]

So, what's the new plan...?

[XframeFX]

10 hours ago, EmTee said:

So, what's the new plan...?

Still working on a plan which may include a dual circuit conversion. I didn't do it earlier because I had too many issues needing attention on the Riviera. Now, I still have numerous issues but the power booster is at the top-of-the-List. Plus, another project needs to be returned to "roller" status once WSWs arrive - busy!

[XframeFX]

Another path would be to install one of these. However, late model Jeep Wranglers (JK) are a rare sight in wrecking yards.

The Pump would wear out quickly having to run constantly due to the leak.

 

 

[RivNut]

My 1983 Riviera XXs had a hydro boost power booster setup.  The power steering pump was used to provide boost for the brakes.  A lot of muscle car guys with high horsepower engine use hydro boost because their engines cannot develop needed vacuum.  Just Google Hydro Boost Brake Systems for a better understanding.

[EmTee]

6 hours ago, RivNut said:

The power steering pump was used to provide boost for the brakes.

Same setup on my 2001 8.1 Suburban.  Seems to work well; the pedal feels just like the usual vacuum diaphragm type.

[XframeFX]

On 3/16/2024 at 11:03 AM, RivNut said:

Just Google Hydro Boost Brake Systems for a better understanding.

To fast track, Like-for-Like replacement would be the way to go. Having done that I now know enough to want a 1964-65 Riviera Power Booster and trash that vacuum reservoir/check valve.

 

There appears to be two for 1964-65 just like Carter AFB or Rochester 4GC carburetors for this period. Delco-Moriane or Bendix are VACUUM SUSPENDED Units meaning vacuum on both sides of the diaphragm with integral check valve. I am having trouble locating a Delco-Moraine core.

I soon realized identifying power boosters is a must. However, with Tom T's testimonial I found Harmon's Classic Brake with the Link here. My original 1963 power booster is an AIR SUSPENDED Delco-Moraine Unit with the external check valve and vacuum reservoir, not a Bendix as on the rebuilder's Invoice.

Stock images with all these Auto Parts Suppliers do not identify which Power Booster you are about to add-to-cart including rockauto.com

 

I wish I started here first. A must, highly recommended:

https://harmonclassicbrakes.com/boosters-and-parts/

 

A helpful Member has a 1965 Riviera Power Booster available but it has been ID'd as a Bendix Master-Vac Power Booster. I'm OK as it should bolt-in but too many versions of Bendix, confusing.

So which two power boosters would be the most reliable leak-free unit? Not the 3rd Unit.

 

 

Research continues as well as a suitable replacement.

 

[1965rivgs]

John, I dont think the check valve on the pictured Bendix unit is correct.

 

Tom Mooney

[Jim Cannon]

John, you are making things way more difficult for yourself than they need to be.

 

The main difference between the '64-65 Bendix vs. Delco booster is the depth of the hole in the piston on the Master Cylinder that goes on it. One is deep (like 1") and one is shallow (like 1/4"). Just get one of the boosters that you like and then get the MC with the correct hole depth to match.

 

At the same time, you can go with the dual master cylinder that matches the booster you got and convert the car to a dual system. That's up to you.

 

I had my '63 booster rebuilt and put a dual MC on it. It works great.

 

If you use a MC that is later than a '63, you will have to add a port for the brake light switch (or make other provisions for the brake lights inside the car on the brake pedal arm).

 

 

[XframeFX]

4 hours ago, Jim Cannon said:

John, you are making things way more difficult for yourself than they need to be.

Thanks Jim. the inferior 1963 Unit has to be addressed with the master cylinder, the rebuilders insist on installing a rebuilt or new master cylinder. Probably because that flakey square profile O-Ring only seals for vacuum. The master cylinder for power brakes has 2 cups on the piston to prevent brake fluid entering the power booster.

 

The only thing that has changed is that my original 1963 power booster is not a Bendix but an early Delco that was used only in 1963. I still want it gone, cut my losses and move on to a better unit.

 

This will be my 3rd GO at this. I was aware of the 1 5/8" depth master cylinder piston the 1st attempt.

 

Difficult? Yes, can't find a replacement! "Send us your CORE and we'll rebuild your power booster".

 

 

 

 

[XframeFX]

So far, unsuccessful acquiring a 1964-65 Delco Power Booster. Now too busy to deal with it. Re-thinking how to make-do with what I have.

I wonder what could go wrong? Thinking the floating control valve.

 

I'm convinced there's no leak at the Master Cylinder after re-fitting 3X. During the 3rd install, would've doubled-up on that square profile O-Ring if I had a spare. Might've helped?

No way to really test after the install. Sure, spray starter fluid at the flange with the engine idling but that would compromise power booster internals and void their laughable 2-year warranty.

 

Everyone with an original 1963 power booster should test for operation as per shop manual.

 

I found another 9" power booster at the bottom of one of my bins. But it's another '63 1st Gen Delco.

 

 

[BulldogDriver]

John have you by chance bench tested the booster using a Mityvac? Cap the ends off and pull 18-21” of vacuum and see if it holds. If your ears are still good, have a listen for the leak or get an assistant that can hear, I have to all the time now days.
 

When I went to dual circuit/disc brakes I eliminated all of the original stuff and went with unit from a 70’s buick. Pedal is a bit harder but it stops just fine.

 

Ray

[EmTee]

19 hours ago, XframeFX said:

No way to really test after the install.

You could try placing the end of your unlit (valve open) propane torch there instead of spraying starting fluid.