D. Yaros

Car is a 1962 Oldsmobile Dynamic 88. The MC is bone dry and I have no pedal.

A quick check at the back of each wheel and of all hoses/lines shows no obvious break/leaks.

Nor is there any sign of lost fluid on the garage floor.

Where and the H could the brake fluid have gone?

MDchanic

Into your brake booster, or, if manual, your firewall insulating pad.

Sounds like a bad master cylinder. It likely leaked out the back.

This would be a great time to upgrade to a dual circuit system!

- Eric

Fun71

I agree. Years ago my MC leaked into the booster, then about a year later the booster failed.

Tedd Thompson

X2 or 3 on the booster, but I would also pull a wheel or two and just for the hell of it see if they are indeed dry. I have a Land Cruiser that had bad wheel cylinders that showed very little fluid leakage on the backer plated but were wet on the inside.... Tedd

Koda

I blew a master cylinder on a Chevy, straight down the front of the booster. Newer booster, so it is quite possible it could go into it like said above on older ones.

D. Yaros

Well, I do not want to sound ignorant, but does a 1962 Olds Dynamic 88 with PB have a booster? If so, where is it located?

I ask as none of the national parts suppliers list such a part, and I have no tank attached to the firewall. My MC mounts directly to the firewall.

The attachment is representative of the MC on my car.

MDchanic

If you have no booster, than you have no power brakes.



- Eric

D. Yaros

Based on the pic of MC I provided above (Msg. #6), am I dealing with a Delco-Moraine unit or a Bendix?

D. Yaros

Questions on brake/MC probs:

1 - How do I tell if I have a Bendix or Delco-Moraine unit?
2- In terms of a MC rebuild does it make a difference in terms of parts whether mine is a
Bendix or a Delco-Moraine?
3- Is it possible to do a rebuild of the MC without having to remove the vacuum
booster?

Appreciate some guidance here, as would like to start this project on Sunday. Thanks.

MDchanic

The Bendix unit is held together by 8 screws, while the Moraine unit is held together by interlocking "fingers" like the units on later cars.



Yes, they are different.



Depends.

For a Bendix unit, you remove the four nuts and remove the M/C from the booster.

For a Moraine unit, you remove the four nuts and remove the M/C from the booster, BUT the piston stays behind, attached to the booster, and the booster must be disassembled if you want to remove it.
Also, there are shims between the M/C and the booster in the Moraine unit, and you need to find and reinstall all of them.

- Eric

D. Yaros

Eric,

Thanks. Your reply is helpful.

Bottom line appears to be that I will have to remove it to ascertain which unit I have.

YOU STATE: The Bendix unit is held together by 8 screws, while the Moraine unit is held together by interlocking "fingers" like the units on later cars.

Where should I be looking for/will I find these "8 screws"?

MDchanic

Nope - Just look at it.





- Eric

D. Yaros

Got it! As they say, a pic is worth a thousand words. Thanks for your understanding and patience. Definitely a learning experience for me!

MDchanic

Hey, that's what we're here for.

All of this information is in the Service Manual, but it is not laid out in a way that makes these distinctions clear, so it is entirely reasonable that you may need a few pointers.

Once you know what you've got, the manual should be able to guide the rest of the job.

- Eric

D. Yaros

In fact, I remember reading about the disassembly of the Moraine unit, but the text and pic did not make a whole lot of sense to me. Now it does!

ANOTHER QUESTION: Is there a separate rebuild kit for the vacuum cylinder?

My thinking is, while I am in there I might as well rebuild both the MC and vacuum cylinder.

MDchanic

Sorry, while I believe there have been rebuild kits for these, I have no idea whether any are left now.

You may find one if you check around though.

- Eric

D. Yaros

UPDATE: Removed both MC and the booster. Booster is a Moraine single diaphragm unit. Disassembled both.
Saw nothing obvious saying "fix me!"
Have sent combined MC and booster off for rebuild.
Awaiting return so I may install.

twintracks

If you did not find brake fluid inside the booster (where it does not belong), you may have a leak somewhere else in the system.

D. Yaros

The booster did indeed contain fluid. It is now being rebuilt.

Interestingly, the rebuilder reports that while I do have a Delco-Moraine booster, my MC is a Bendix. I find that a bit odd as I did not think "mix & match" was an option; especially given the 2-bolt/4-bolt differences in the MCs?

Here is a pic -

MDchanic

Yes, but Bendix may have made replacement M/Cs to the Moraine standard.

- Eric

D. Yaros

I am able to report that I do once again have brakes! The booster/MC combo has been rebuilt and reinstalled. I also replaced all the hydraulic brake hoses while I was at it.

This job was, to say the least, a royal pain. The most difficult task was getting the MC brake line fitting back on. Absolutely absurd the time and effort required to accomplish that!

I ended up separating the MC from the reinstalled and mounted booster to get the brake line and fitting to line up with MC port. Then it took a while to figure out how and the heck to once again get the MC mated to the vacuum assist booster. I was more than surprised how much force was required to overcome the pressure exerted by the MC piston.

Luckily, all is back together now and working as intended!

MDchanic

Congratulations! I bet you feel a whole lot better now.

- Eric