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gregleck

Moraine and Bendix power brake units - interchangeable?

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Brake booster on my 1962 Olds Dynamic 88 is leaking - on long, steep hills the vacuum is lost and pedal goes to the floor.

 

Since the car can still be driven, I decided to find a used replacement, have it rebuilt, then install it. (No NOS or rebuilt available)

 

When the part arrived, I saw it did not match the one in my car.

 

Booster in my car - black colored vacuum cylinder = Bendix booster

 

Used booster part - bronze colored vacuum cylinder = Moraine booster

 

Are these interchangeable?  Master cylinders for each are different too.

 

Thanks,

Greg

 

 

 

 

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Benefits of AACA Membership.

Correct -- Different -- And Not interchangeable....

(Although some will chime in, you can make anything fit.... They believe you can use one out of a 2013 Kia...)

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1 hour ago, gregleck said:

Brake booster on my 1962 Olds Dynamic 88 is leaking - on long, steep hills the vacuum is lost and pedal goes to the floor.

 

Sounds like a master cylinder problem or possibly a leak, not a booster problem.

 

If it's a booster problem, IMHO just yard it out of there and send it out to Power Brake in Portland, OR for rebuild. The turnaround is fairly quick, and it will be done right, No BS. I have had 2 boosters done there in the last 3 years or so.

 

http://boosterdeweyexchange.com/

 

 

 

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Posted (edited)

 

 

 

Quote

Sounds like a master cylinder problem or possibly a leak, not a booster problem. 

 

Forgot to mention that there is a loud hissing sound whenever pressure is applied to the brake pedal. No leaks from master cylinder.

 

14 hours ago, Bloo said:

If it's a booster problem, IMHO just yard it out of there and send it out to Power Brake in Portland, OR for rebuild. The turnaround is fairly quick

 

I spoke to Brake Boosters last week - they said to expect 6 to 12 weeks turnaround now with COVID

Edited by gregleck
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How would I find the original GM part number for the Bendix brake booster?

 

I see NOS boosters for sale but the sellers usually don't know the year and model the part is for.  There is a part number on the box, though.

 

In this case, the 1962 booster was also used in the prior year models.

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While the hissing certainly indicates a vacuum leak in your booster, a bad booster alone shouldn't cause your pedal to sink to the floor.

if anything, it would be more difficult to depress the pedal with the loss of the vacuum assist from your booster.

Are the master and booster still on the car?

I would take a good look at your master cylinder, particularly if you've never had it apart.

A similar situation occurred to me years ago on a '61 Olds with a soft, sinking pedal.  Couldn't find a leak anywhere.  Then I removed the master & booster, and discovered that the booster was half-full of brake fluid that had leaked past the piston in the master cylinder.

The bore in the master was very badly pitted, which tore up the seals on the piston.  I wound up with both a rebuilt booster and a sleeved master cylinder, which took care of the problem. 

That scared me enough to go around the car and check the wheel cylinders, which weren't much better.  By the time I was done, the whole brake system was new.

It's not much fun having your car laid-up unexpectedly while waiting for parts, but ensuring that it has reliable brakes is one of the most essential things you can do for your own safety and that of those around you.

Good luck!  

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You may find that booster full of brake fluid. It often causes failures. Even if not, the only part that can cause a pedal to go to the floor without a leak is the master cylinder. It can leak back into it's own reservoir.

 

Other causes of no pedal could be a system full of air, brakes way out of adjustment, blown wheel cylinder, hole in a brake hose or a steel line, etc. Not the booster though. All it does is help push.

 

I would just send it out to Power Brake (Portland) and send the master cylinder to Brake and Equipment (Minneapolis). I would not be thrilled about the wait at Power Brake either, but you would would get quality rebuilds of parts you know fit and work because they came off of your car. You could easily screw around for longer than 6 weeks with parts that don't quite fit. Best of luck whichever way you go.

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On 7/30/2020 at 11:54 PM, gregleck said:

How would I find the original GM part number for the Bendix brake booster?

From Nov 73 parts book. Keep in mind Olds refers to all 61-72 A-body cars as F85.

 

Booster Grp 4.901 p/n 383050

61-2 except F85

63 except F85/police

64 except F85 all w Bendix booster

 

Repair kit Grp 4.898 p/n 391514

61-64 except F85, Bendix

 

I'd be wary of 50 year old rubber parts even if they've never been used, due to dry rot. I think, if you have the luxury of time, I'd have the original rebuilt.

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On 8/1/2020 at 7:26 PM, rocketraider said:

From Nov 73 parts book. Keep in mind Olds refers to all 61-72 A-body cars as F85.

 

Booster Grp 4.901 p/n 383050

61-2 except F85

63 except F85/police

64 except F85 all w Bendix booster

 

Repair kit Grp 4.898 p/n 391514

61-64 except F85, Bendix

 

I'd be wary of 50 year old rubber parts even if they've never been used, due to dry rot. I think, if you have the luxury of time, I'd have the original rebuilt.

 

part number 383050 is listed as a "switch."  

 

Is that correct?

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On 8/1/2020 at 12:45 AM, Bloo said:

I would just send it out to Power Brake (Portland) and send the master cylinder to Brake and Equipment (Minneapolis). I would not be thrilled about the wait at Power Brake either, but you would would get quality rebuilds of parts you know fit and work because they came off of your car. You could easily screw around for longer than 6 weeks with parts that don't quite fit. Best of luck whichever way you go.

 

Sound advice, especially coupled with the observation about safety.

 

Forty years ago, I picked up this same model car from a tire shop.  Unbeknownst to me, someone pulled the brake hose out and the wheel rubbed against it.  Two miles down the road traffic stopped and the pedal when to the floor.  Pumping the brakes brought the car to a stop.  Brake reservoir was full.  No leaks in system but when pressurized, fluid sprayed out of the worn spot in the brake hose.

 

Looks like after the rebuilds, cylinders, drums and shoes will get a good going over.

 

 

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Parts book says 4.901, 383050 is "CYL. (Bendix)".  4.901 group lists as cylinder assy., Bendix power brake power assist.

 

Does that p/n show up as something else?

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After 47 yrs that p/n has probably been obsoleted and assigned to something else. Try adding the group no. 4.901 to your search. Those were the part #s that were in the system when the cars were ten years old and still considered part of the dealer parts and service system.

 

Does your search id what kind of switch or what application?

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Dug out my January 1965 parts manual tonight. In addition to the 383050 p/n for Bendix booster in the 1973 book, the 65 book shows 4.901 582944 for 61-62 exc F85, and 4.901 380029 for 1963 exc F85 or 88 police car. Looks like 383050 was consolidated for 61-64 B&C car w Bendix brakes by late 1973.

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