[Tennesseestorm]

I usually only drive my 73' on my day off- which was today. When I got in it to start it this morning- it made an odd noise under the hood- like a "whining" noise. A little noise like my tranny makes all the time when shifting from 1-2, but it was louder. It stopped after about 10 seconds. It had never did this before, but I did change the fluid and filter last Wednesday. My main problem for now is that when I went to take it out of park, the pedal was very soft and went to the floor and braking power was very minimal. With a quick initial inspection, I did not see any fluid leaks from any of the wheels or booster/master cylinder. It was bad weather today, so not much time to inspect it.

Does anyone have any ideas just from what I have posted? Someone said it could be a busted wheel cylinder. The car is 33 years old and the entire system is original, so I guess it is time for something to go bad. Dad said it may be the master cylinder failing. The brake warning light was not illuminated during this, but the light does work, because it comes on when I turn the ignition and when I set the emergency brakes.

Any info appreciated.

[Tennesseestorm]

I usually only drive my 73' on my day off- which was today. When I got in it to start it this morning- it made an odd noise under the hood- like a "whining" noise. A little noise like my tranny makes all the time when shifting from 1-2, but it was louder. It stopped after about 10 seconds. It had never did this before, but I did change the fluid and filter last Wednesday. My main problem for now is that when I went to take it out of park, the pedal was very soft and went to the floor and braking power was very minimal. With a quick initial inspection, I did not see any fluid leaks from any of the wheels or booster/master cylinder. It was bad weather today, so not much time to inspect it.

Does anyone have any ideas just from what I have posted? Someone said it could be a busted wheel cylinder. The car is 33 years old and the entire system is original, so I guess it is time for something to go bad. Dad said it may be the master cylinder failing. The brake warning light was not illuminated during this, but the light does work, because it comes on when I turn the ignition and when I set the emergency brakes.

Any info appreciated.

[6t7gto]

shaffer,
my 67 gto did that last spring.
backed it out of the garage after sitting all winter. pedal went to the floor but i still had some brakes.
no external leaks, that i could see.
M/C failed and booster was full of fluid.
had to replace both of them.
david

[PMDRACER]

Pulling the cap off the master will tell the tale. If the fluid is gone on one side, you know where to look. Also, you should also see brake fluid all over the lower part of the booster if it has failed. Sometimes you'll find brake fluid inside the vacuum hose coming from the booster too.

If it's all original like you say, I'd plan on rebuilding the entire brake system on your next day off.

[ctgross]

My 66 did the same a few months ago. Seal on the plunger at the rear of the master cylinder was letting fluid to be sucked into the booster unit. Mine had only done it a few days before I figured it out, so I don't think it hurt the booster. I rebuilt the m/c, pumped the fluid from the booster and put some soapy water in the booster and then pumped it out. Clamped dry rags on wire and dried the inside of the booster. About 5 months now, no problems so far.

[Tennesseestorm]

Thanks for the replies. I dodged the rain squalls today and checked it. The rear reservior is out of fluid. ALL of the wheel cylinders are fine- no leakage. There appears to be a break in one of the lines as it does down toward the back of the car near the front floor.

If something happens it is the booster and it needs replaced- how difficult to replace? Don't you have to go under the instrument panel to remove the bolts?

Thanks again!

[6t7gto]

only thing under the dash is the anchor pin from the booster to the brake pedal.
the rest is under the hood.
four nuts on the firewall behind the booster.
use a rachet box wrench. makes it a lot easier to get the four nuts off.
david

[6t7gto]

shaffer,
scratch that info above.
i just checked napa website for a full sized poncho, and the nuts for the booster are definitely under the dash.
have fun.
david

[Tennesseestorm]

I thought that first reply was too easy to be true.

Hopefully it is not the booster at all. Thanks again!

[Tennesseestorm]

STUPID BRAKES!!!!

Finally got a brake booster and after 3 hours of work, (I have never done anything like this before) I finally got it on- broken back and all. The biggest problem I had was probably the most simple to some, but I had a time getting the plunger rod off of the brake pedal pin.

The wonderful news is that the new booster is bad. It is whistling like crazy when I depress the brakes. We have bled everything. What is also strange is that no fluid will come out of the front wheel lines. The brakes are working fine is another thing that is puzzling. At first, the brakes were going down, but not coming back up. After we bled them more, it started to come up properly. We called the auto parts shop and they said a new one would be in on Thursday morning. Now I get it look forward to removing it again! Just my luck.

Another thing- the replacement booster looks much larger than the original. In fact, it seems to be making the wires that run by it put too much pressure where they come out of the harness. Possibly they sold me the wrong one? Everything bolted up OK though. (see "replacement booster too large?" thread)

[gotpls]

Check and make sure that the adjustment rod is the same lenghth between master cyl, and the booster, also check for a collapsed front line, it sounds like your rear brakes are working but the fronts are not getting the fliud they need. I would consider breaking the line where it attatches to the metal line and see if you are geting fluid there, then you will know where to go. Good luck

[Tennesseestorm]

Thanks. I am totally clueless, because until my booster went out, the brakes were in perfect order. The car would stop on a dime, even on wet roads, so I am sure even the front brakes had to be working. Perhaps it was the faulty booster causing the front brakes not to pump up?

It has really been a headache. They had to end up ordering a booster (bendix - whatever that means) for a 1972 Grand Ville, even though my car is a 1973. This "bendix" booster was the smaller booster like was on my car originally, but was not listed under the 1973 model for some reason. My car was an extremely early 73' model- made in August of 1972, so I guess they carried over that booster on my car, but I have no idea why they switched to the larger booster on the 73's, because it seems like it is too tight with that one- because it (the replacement I originally got that was faulty) was almost touching the steering sector and was against the wiring harness loom. I was glad to get that one removed quickly. The one I just got for the 72, was identical to my original, so there are different ones it seems. Now- my problem is that this one did not come with the master cylinder already on it. No big deal- he said they had one in stock. When I went this morning to get the bendix booster they had to order- he said they did NOT have that cylinder and had to order it, so I will not have it until tomorrow.

I just cannot wait to get this fixed once and for all. It has been a week and all of this mix-up is crazy, just for something as simple as a booster/master cylinder.

Does anyone have a 73-76 full-size with a large booster? Larger than the one I showed?

[Tennesseestorm]

I guess it would help if I had the photos posted. Duh....

First- here is my original booster:

[Tennesseestorm]

Here is the replacement booster they sold me. A very tight fit- not to mention this one was defective.

[Tennesseestorm]

Here is another view of the old booster. The "bendix" booster which I got them to order was installed today. It is identical to my original booster- which as you can see is much smaller in diameter. What was weird is that this bendix booster was only listed under the 1971-72 Grand Ville and not the 73'.

I will post a photo of the new booster tomorrow.

[Bad Karma]

Man that old one is Crusty no wonder it failed lol. Just be happy NAPA still carries parts for a 30 year old car. Someday We'll have to pay top dollar for Repro Parts since the Napa/autozone Cant get them anymore. I agree though I have gotten the wrong parts more than once from Napa and Parts America. I find That Most Napa Parts Are better Quality. I only use Napa because The Clerk Is a Family Friend and I get the Parts at the Wholesale Price which helps alot.

[Tennesseestorm]

Yeah, it was getting pretty bad. My entire engine compartment is dirty like that, but not rusty like the booster was. The engine in my car has obviously NEVER been cleaned- which really looks dusty after setting idle in a garage for over 10 years. I guess the booster was crusty after all of those years of brake fluid.

I plan on cleaning the engine soon- by spraying it with "simple green" cleaner (which has worked well for me in the past) and spraying it with a garden hose, rather than a high pressure sprayer. Then I can start painting the necessary areas and getting the only sticker I think I am missing- "Keep your GM car all GM" is missing from the air cleaner.

See what I mean- here is a photo of my engine taken after I bought the car- still looks the same.

[Tennesseestorm]

Another- of the engine