I've just recently purchased what I was told is a 1969 442 but am starting to realize is likely a clone. After doing some research with the VIN it looks like the car is a cutlass but I have paperwork showing an engine swap for a rebuilt 400 CID (I hope this is accurate). I'm having some brake problems. I was told that the car has a new master cylinder. However, after only a couple of weeks, I've lost braking ability. When the car is off, the brake pedal gives full resistance. When the car is started, a vacuum sound can be heard coming, I think, from the master cylinder. This sounds can be heard even from inside the car. When the brake pedal is pushed it meets little resistance and then goes to the floor. The car will stop but it takes MUCH longer than is safe. When the pedal is depressed the vacuum noise stops completely. I found in the stack of records from the PO a document from when the master cylinder was replaced in 12/2010. This receipt has a handwritten note saying that the MC has been replaced 3 times and the pedal goes to the floor. HELP! Does this problem sound like the Master Cylinder? For all I know, the car has original disc in front and drum back. I have attached a couple of pictures in case they'll help. Thanks in advance for help on my first post.

 

I think first I'd check the vacuum hoses and see if there are any cracks or issues. Also then I think I'd see if you could get the power brake booster diaphragm checked out as it might have cracked. Have you noticed any brake fluid on the brake pedal rod? Also maybe check the brake hoses and wheel cylinders and calipers for any leaks. I hope this helps

John

 

Check the master cylinder and see how much brake fluid is in there. You might have a leak somewhere. If the car had all the brake lines bled, possibly someone forgot to tighten one of the bleeders all the way and you've lost fluid gradually. Also check to see that the brake lines to the mc and proportioning valve are not leaking. You might need to rebleed the master cylinder and all brake lines again. Usually when the pedal goes to the floor, you've got air somewhere in the system. I don't think it's the brake booster. If the diaphragm wasn't any good, it would result in a stiff pedal pretty much all the time.

 

Just disregard what the previous owner might have or has done - with brakes you gotta start from scratch!
Could mean lives!
While the car is running, pull off the large vacuum hose to the booster, and cover the hole with your thumb. If the hissing stops, it's the booster - if it continues, it's either the hose or plastic connector - replace as necessary!
The going to the floor part puzzles me - let's see what happens after the vacuum fix!
If you don't feel up to getting dirty, take it to a Midas and get a diagnosis - should be free, except for towing!
If it was me, not knowing the history, I'd be checking/replacing the entire system on a 42 year old muscle car!
I'm getting too old for accidents!

 

Thank you very much, guys. I'll do some exploring this weekend and report back.

 

Is that a Performer RPM intake manifold I see there?
If so, that is not a 400 engine. The Olds 400 (both versions) was a big block. Edelbrock only makes the Performer RPM for small block Olds engines.

(OK, before someone busts me on that statement, let me qualify it with: yes, now they make an Air-Gap version for BBO, but they are brand new and not common yet - and the pictured intake is obviously not one)

If you post the casting numbers at the top of the engine's timing cover area behind the water pump, we can tell you what it is. Also check the large letter or number on the left end of the cylinder heads.

 

Well after looking at the casting numbers and doing some research I realized you are correct, I do have a 350. I tracked down the guy that sold it to the manmy I bought the car from and he sold it as a cutlass s with bench seat and column shift. I got ripped off with a clone. Now I'll try to ask for my money back and possibly take him to court? Thanks for your help. I feel like a sucker.