Moraine and Bendix power brake units - interchangeable?

[gregleck]

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

 

 

 

 

[mobileparts]

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...)

[Bloo]

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/

 

 

 

[gregleck]

 

 

 

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 July 30, 2020 by gregleck
format (see edit history)

[gregleck]

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.

[Starfire61]

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!  

[Bloo]

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.

[rocketraider]

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.

[gregleck]

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?

[gregleck]

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.

 

 

[rocketraider]

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?

[gregleck]

have google searched it without luck.  but "GM part number 383050" comes up as "switch"

[rocketraider]

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?

[rocketraider]

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.

[gregleck]

Have sent the Moraine brake booster back.  They are going to send a Bendix, which I will have rebuilt.

 

Have determined the current brake booster is aftermarket.  It also appears the reserve vacuum tank is missing and the aftermarket booster does not have the fitting for the reserve tank.

 

I see two bolts in the firewall under the driver's side fender.  Is this likely where the reserve vacuum tank was attached?  Illustration in the '61 shop manual is not very good as to location.

[rocketraider]

For some reason I was thinking only cars w Starfire engines had the reservoir tank under the fender. See if you can contact Dave Yaros. He just sold his 62 D88 convertible but either he or Oldsfan will know for sure.

 

Sorry I haven't been more help.

[Starfire61]

All '61-2 full sized Olds with power brakes used the vacuum tank.

Both the Bendix & Moraine boosters came with an integral T-shaped connection, one side of which went to the engine, and the other to the tank.  

The tank itself attaches to the inner fender with three bolts accessed by removing the left front wheel.

The left hood hinge might need to come off in order to remove or install the tank.

Pics are attached.

Note that the Moraine booster has only two studs for the master cylinder, while the Bendix has four.

Moraine boosters are anodized and held together with locking tabs, while Bendix are painted & assembled with screws.

The other big difference between the two is that the master cylinder piston on the Moraine system is physically a part of the booster, while the Bendix has a separate piston that's assembled into the master cylinder with a snap ring before the whole assembly is mounted on the booster.

Looking at your photo, it appears that somebody threw some available parts together in a half-baked attempt to just get by.  Obviously, the tank is missing, but the big red flag is the 4-stud master cylinder attached to the 2-stud booster.

Since this is clearly a replacement booster, I'm not certain that this car has mixed & matched Moraine & Bendix parts, but I would be very leery about driving it until you figure out what's going on.  At best, it's slipshod.  At worst, it could be dangerous.

Given the recent braking issues, this is probably a good opportunity to tear into this stuff & make it right.  Not the most glamorous task imaginable, but it will give you peace of mind knowing that your brakes are as good as they can be.

 

[gregleck]

Quote

Note that the Moraine booster has only two studs for the master cylinder, while the Bendix has four.

Moraine boosters are anodized and held together with locking tabs, while Bendix are painted & assembled with screws.

Yes, what I found in description by other people:

Moraine - brass colored, two studs for master cylinder, held together by locking tabs.

Bendix - black colored, four studs for master cylinder, held together by eight bolts.

 

Quote

Looking at your photo, it appears that somebody threw some available parts together in a half-baked attempt to just get by.  Obviously, the tank is missing, but the big red flag is the 4-stud master cylinder attached to the 2-stud booster. I'm not certain that this car has mixed & matched Moraine & Bendix parts, but I would be very leery about driving it until you figure out what's going on.

Yes, that is the same conclusion I came to.  There is no T piece.  And when I looked, there was no vacuum reservoir tank.  And though the booster is black, there are only two studs for the master cylinder.  Nevertheless, I did drive the car on a 500 mile trip last month.  

 

My theory is the car did not come from the factory with power brakes.  At some point someone decided to add an aftermarket brake booster.  (And to think the auctioneer kept crowing, "100% original!")

 

I was told the Moraine and Bendix units are NOT interchangeable.  I am guessing this is due to the bolt pattern? 

 

At this point I decided not to worry about the "name" of the booster and instead match the bolt pattern. Gave the salvage yard the measurements.  They sent me a reservoir tank and booster/master cylinder unit from a '62 Olds.

 

Now here is what is odd.  The master cylinder has "Moraine" stamped into the metal   The booster is gold colored, and is held together with clips.  BUT IT HAS FOUR STUDS FOR THE MASTER CYLINDER.  And the bolt pattern fits my existing master cylinder.

 

Photos are posted for future reference to help anyone else trying to sort out their brakes on a full sized 61-62 Olds.

[gregleck]

Here is an update: 

 

On 9/18/2020 at 8:20 AM, gregleck said:

Now here is what is odd.  The brake booster has "Moraine" stamped into the metal   The booster is gold colored, and is held together with clips.  BUT IT HAS FOUR STUDS FOR THE MASTER CYLINDER.  And the bolt pattern fits my existing master cylinder.

Sent the Moraine out to Brake Boosters in Portland, Oregon.  12 week turnaround due to protesters, rioters, and Postal Service delays. 

 

When it came back, even though the bolt pattern fits, the new, reconditioned Moraine did not fit my master brake cylinder because the plunger would not work with the master brake cylinder, which is either a Bendix or an aftermarket replacement master brake cylinder.  (No identifying marks)

 

At this point, I looked at the Fusick Olds catalog and it looked like the master cylinder from the 1960-1961 full size Olds should fit my Moraine Booster.  1962 used 1961 master brake cylinders and boosters, either Moraine or Delco.  I was ready to order it but when I asked about returns, was told "once you buy it, you own it."  Instead, it was suggested that I send in the old master brake cylinder which had been attached to the junkyard Moraine booster I purchased from a salvage yard in Idaho.

 

Of course, it was not that simple, because by now COVID was playing havoc with the USPS and it took weeks to get to Fusick, a week for them to figure out that yes, the 1960-1961 Moraine master brake cylinder would work, and, despite Priority mail, another two weeks to get it back.  So now, I have a new OEM Moraine master brake cylinder, a reconditioned Moraine brake booster (painted black!), and a nicely refinished vacuum tank.  All I have to do now is get them in.

 

Thanks to all for your help and suggestions.

 

[gregleck]

On 9/11/2020 at 9:09 AM, Starfire61 said:

the master cylinder piston on the Moraine system is physically a part of the booster, while the Bendix has a separate piston that's assembled into the master cylinder with a snap ring before the whole assembly is mounted on the booster.

 

And THIS is why the two systems are not interchangeable, not because the bolt patterns don't line up.

[gregleck]

Two more points for anyone who finds themselves in this situation.

 

1.  Although the boosters are not interchangeable, they can be made so by taking the plunger out of the Bendix master brake cylinder and installing it in the Moraine brake booster.

 

2.  If you are replacing an aftermarket brake booster, or a post 1964 booster which was put in your older car, the newer boosters contain a vacuum suspended check valve inside the booster.  The older boosters do not have these and rely on an inline vacuum check valve located in the vacuum line between the engine and the booster.  You can see the location in the photo of the red car above.  So by going back to the original design, you will need to install the inline check valve since the newer boosters did not need them.