67 leSabre power brake conversion

HarryLeSabre

HarryLeSabre

Member
Hi Buick enthusiasts! :cool:

I'm Harry from Hamburg/Germany and just bought my absolute childhood dream car, a 67 leSabre Coupe w/ 340-2 engine and ST300 tranny.

Now, as the first owner did not tick the "power brakes" option back then in 1967, the car is not very keen on braking - to put it simply. I've got other (german) cars of similar age w/o power brakes, but they are maybe half the weight of the Buick, so its a completely different story. To make matters worse my wife would like to drive the leSabre too - and shes having difficulty to put enough force on the brake pedal.

So to convert the car to having "power brakes" I'm assuming that the only required step/part is to obtain a matching "brake booster" and mount it between the master cylinder and the firewall/brake pedal linkage.

Is it really that simple or do I have to change/modify other parts as well?

- Is the "non power brake" master cylinder compatible w/ an added booster or do I have to get a different master cylinder?
- How about the brake lines - do they have enough slack to allow the master cylinder being moved a bit to the front of the car? Is there actually just one "universal" type of brake lines in those cars or different types for "non power brakes" or "with power brakes"?
- Where/how exactly do I connect the brake boosters vacuum line to the carburetor (probably Rochester 2bbl)
- Would this be the correct booster? https://www.rockauto.com/de/moreinf...hSgQVbpRTC12SeSDBIIYioRUMZG92CAvEks9xJhdDbuqp

Thanks in advcance for any help!

Cheers,
Harry

P.S.: If you are expected to introduce youself as a new member at a different/specific spot here, please point me into the right direction. Thanks!
 
Yes, power brakes are as simple as you think. The brake lines are the same. The booster must have manifold vacuum, usually from a fitting either mounted on the manifold behind the carburetor or near the bottom of the carburetor it's back side.
The car should stop well without the power option although with more pressure, you should inspect the brakes and make sure the are functioning properly and in good condition.
67s are a good year!:)
 
Hi Bob,

thanks for your answer and yes, the car indeed stops "normally", if you remember to stomp on the pedal with both feet ;-)

Could you or someone else give me an idea if the brake booster linked in my originial posting is the correct part?

Cheers,
Harry
 
According to my book, it looks like you should be using one for 1967-68 LeSabre, Wildcat, Electra, Riviera. no.5452486 (Moraine).
 
Bob,

I'm not able to find anything available using that no (5452486), the only compatible part so far seems to be "Quality-Built B1425":

Power Brake Booster

Power Brake Booster
catalog.motorcarparts.com catalog.motorcarparts.com

Unfortunately they don't give any measurements for the bolt patterns etc, so for me its "trial and error". And since I'm located in Germany a possible return (if it does not fit) will be troublesome and/or expensive...

Cheers,
Harry
 
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I would expect that it will fit, but... (pictures on the web are not accurate) if you are concerned, I would choose to order from a reputable supplier of classic Buick parts, or at least classic car parts. I would probably also choose a properly cadmium plated one that looks nice and correct. During the order process, you will tell them what you are ordering it for, then they can tell you what will fit.
 
I would agree with Bob that the B1425 booster should fit properly if all the specific parts for a Delco Moraine power drum brake setup are present. The description of the B1425 indicates it is a remanufactured factory unit. So it is not a new, reverse-engineered assembly that might suffer from aftermarket design errors.

The master cylnders are not the same for a Delco Moraine manual drum brake system vs the comparable power system. One difference is the long push rod that is supplied with the manual cylinder. The power master cylinder only has a cupped piston which is operated by two external pushrods. The cylinder bodies are stamped with different code letters. The pistons are coded differently as well.

The 5452486 part number shows up in the Buick Master Chassis Parts book as the master cylinder for 1967-70 full size Buicks using the Delco Moraine power drum brake setup. The parts book also shows numerous different part numbers for a manual vs. power system. These include mounting brackets, reinforcement plates, and the pedal arm etc.

More info on the brake system is shown in shop manual brake chapter available here on this site:

1967 Buick chassis Service Manual, FREE ONLINE

www.teambuick.com

Attached are a couple of pages showing brake unit mounting details for the manual and power systems. The page for the power system shows the elbow on the intake manifold which provides vacuum for the brake booster.

The most effective way to do the conversion using original equipment parts would be remove all the brake system components down to the distributor block/switch assembly from a Delco Moraine power drum brake car and transfer them to your car, rebuilding items as needed. Could the parts from the manual setup (other than the master cylinder) be modified to work with the power brake master cylinder and booster? Maybe, it would be hard to tell without having both sets of parts side by side to compare.
 

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Hi Bob & Todd,

thanks for your replies and the valuable information provided!

I just took a closer look of my car and even dove beyond the dashboard to examine the brake pedal assembly and linkage to the master cylinder.
If I compare the two pages from Todds post, it seems most parts are identical - but of course I'll need a different master cylinder as well, that much is clear now.

Where the "vacuum elbow" should be attached to the intake my car has a simple threaded plug - so that seems to be compatible as well.

Unfortunately I'm sitting in Germany where those cars and specialized parts dealers are pretty rare. The only parts sources I know of are rockauto.com and ebay.com (if seller is shipping here at all...).

Do you maybe have/know of other Buick parts sources that offer international shipping?

Cheers,
Harry
 
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Since you are buying in the U.S. & dealing with non Buick specific parts suppliers. May I make a suggestion??? Contact James at Bestoffercounts. He knows his Buicks as that's mostly what he does & his prices are usually fairly compatible with others. Tell him Tom T. told you to contact him.
Contact info: Bestoffercounts Paypal & all major credit & debit cards. BestOfferCounts LLC- James Kehr
2730 Old Bethlehem Pike
Sellersville, Pa. 18960-1245


Tom T.
 
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