Sign in to follow this  
STEVE POLLARD

1969 Impala Brake Question

Recommended Posts

I went to move my Impala out of the garage tonight and the brake pedal almost went to the floor board.... I checked the brake reservoir which was at the proper level and I checked underneath the vehicle for any brake fluid - nothing. The vehicle has drum brakes all the way around the vehicle.  Just very strange, too late to look at it tonight, but before I start to dig into this tomorrow,  any suggestions ?

 

Thanks

 

Steve

 

( I did "pump" the pedal a few times, no change ) 

Share this post


Link to post
Share on other sites

To just move the car a short distance, you can try pumping the brake pedal, but you should plan on rebuilding or replacing the master cylinder as you have been given a signal that it will fail soon.

  • Like 1

Share this post


Link to post
Share on other sites

Does sound like the master cylinder might be failing or something goofy like the linkage has a problem sine there is no loss of fluid.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the input.....I'll focus on the master cylinder.....  the car has 7000 miles on her and I've never did anything with the brakes since I purchased it back in 2004.

 

Steve

Share this post


Link to post
Share on other sites

Typical master cylinder failure.

 

Especially if it sinks more with light pedal pressure than when pressing really hard.

 

2004 is 15 years ago. If DOT 3 filled system, I am surprised it lasted this long. Flush every two years for best results, or just overhaul the  whole  system and use DOT 5.

 

2 hours ago, 19tom40 said:

been given a signal that it will fail soon

 

No signal is it HAS already failed!

  • Like 3

Share this post


Link to post
Share on other sites

Thanks again for the input....is it worth rebuilding or just replacing the master cylinder ? 

2 hours ago, Frank DuVal said:

 

2004 is 15 years ago. If DOT 3 filled system, I am surprised it lasted this long. Flush every two years for best results, or just overhaul the  whole  system and use DOT 5.

Thanks Frank.....sad thing is that the vehicle sits....I do start it and run the engine, but I have not driven it for a while now.

Share this post


Link to post
Share on other sites
5 hours ago, STEVE POLLARD said:

is it worth rebuilding or just replacing the master cylinder ? 

 

Depends on price. Also depends on if you want the original looking master cylinder and the replacement is not similar looking. I do not know if this is the case, just mentioning it can happen.

 

Rock Auto shows AC Delco master is $52,  Raybestos rebuild kit is $21.

 

Sitting vehicle is great with DOT 5, but you have to rebuild all 4 wheel cylinders and flush the steel lines, replace the rubber hoses (just because they are 50 years old!) to change over.

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Frank DuVal said:

Depends on price. Also depends on if you want the original looking master cylinder and the replacement is not similar looking. I do not know if this is the case, just mentioning it can happen.

 

Rock Auto shows AC Delco master is $52,  Raybestos rebuild kit is $21.

 

Sitting vehicle is great with DOT 5, but you have to rebuild all 4 wheel cylinders and flush the steel lines, replace the rubber hoses (just because they are 50 years old!) to change over.

Thanks Frank ! 

Share this post


Link to post
Share on other sites
8 hours ago, iowa-k said:

Is there an easy way to tell if the brake fluid is DOT 3 or DOT 5 when it is in the master cylinder?

 

Well, dot5 is slippery, and dot3(or 4) will sort of burn your hands a little. Pretty subjective.

 

Dot3(4) is usually clear or straw colored, and rots to something like dark amber, gray, or black. Dyed versions do exist, like Ate Super Blu, but that doesn't show up too often in antiques.

 

Dot5 is usually pale purple or pale green, and does not rot, so it might not change color much. It could get discolored by the rubber of rotting cups and seals, or tiny particles worn from a brass cylinder sleeve.

 

Dot5 tags exist to put on the cover bolt of a pot-type master cylinder. I'm not sure what to do with a bail.

 

  • Like 1

Share this post


Link to post
Share on other sites
15 hours ago, STEVE POLLARD said:

is it worth rebuilding or just replacing the master cylinder ? 

 

7000 miles? Why not keep the original? If the bore is too bad, you can get it sleeved. I had one sleeved last year at "Brake and Equipment" of Minneapolis, MN. They did a nice job, and could have rebuilt the cylinder too if I wasn't inclined to do it myself.

  • Thanks 1

Share this post


Link to post
Share on other sites
20 hours ago, iowa-k said:

If you do switch over to DOT 5 put a note/sticker/label on the master cylinder to identify what is being used. My dad, since passed away, used both DOT 3 and DOT 5 when rebuilding brake system. I have 3 of his vehicles and have no idea on what is in each of the master cylinders of these cars. 

 

Is there an easy way to tell if the brake fluid is DOT 3 or DOT 5 when it is in the master cylinder?

There is an easy check for 3/5 brake fluid....

Put a sample of old brake fluid in a clear glass.... add a small amount of water... stir up ..wait 5 minutes.

If there is a blob of water at the bottom of the glass...DOT 5 Silicone fluid...if no glob of clear water the water mixed in with the old DOT 3 Brake fluid.

  • Like 2

Share this post


Link to post
Share on other sites

do not over look a wheel cylinder usually it will be evident on back of tire or wheel.if it sits a lot does not take long for a leaking cylinder to drain the master.with the master up on firewall the fluid can and will siphon down over time.

  • Like 1

Share this post


Link to post
Share on other sites

Sleeve job as it came back from Brake and Equipment:

 

wSY8evz.jpg

 

15xV6fM.jpg

  • Like 1

Share this post


Link to post
Share on other sites
On 10/2/2019 at 3:37 PM, STEVE POLLARD said:

Thanks again for the input....is it worth rebuilding or just replacing the master cylinder ? 

Thanks Frank.....sad thing is that the vehicle sits....I do start it and run the engine, but I have not driven it for a while now.

Steve, if you have your original master cylinder on your Chevy, it will have a correct casting number and a casting DATE on it, which match the rest of the components on your Impala. 1969 Chevy passenger master cylinders were typically sort of short with slightly rounded sides. In 1970 Chevy switched to MC's with taller reservoir walls which were flat sided. IF your car is pretty much a matching-numbers car, you might be well served to rebuild and reuse that original master cylinder...at least in my opinion. 

  • Like 1

Share this post


Link to post
Share on other sites
43 minutes ago, lump said:

IF your car is pretty much a matching-numbers car, you might be well served to rebuild and reuse that original master cylinder...at least in my opinion

Thanks Lump for the info.....I'm going to look into rebuilding it and keep it original. When I purchased the car in 2004, it had 5,000 original miles on it...

 

Steve

 

20191015_174447.jpg

20191015_174520.jpg

Share this post


Link to post
Share on other sites

Hmm, no power brake Impala. 😉 I see the master cylinder has been weeping for a long time, as evidenced by the firewall.

 

I would certainly try rebuilding it first, paint it with a cast iron gray, and keep DOT 3,4,5.1 off the outside as much as you can because it will strip your new paint off.

 

Also a good time to lightly touch up the firewall. Carefully, as to not mar the chalk/paint marks visible in the picture.

  • Like 1

Share this post


Link to post
Share on other sites

Steven, 

That is the taller style, but it might the correct original unit, if your car is late 1969 unit. Anyway, in the attached cropped piece of your photo, I have marked a flat-machined spot with the word "HERE" to show you where you may be able to clean away rust and find production date codes. 

Master cyl pic 1969 Impala cropped.jpg

Edited by lump (see edit history)
  • Like 1

Share this post


Link to post
Share on other sites
24 minutes ago, Frank DuVal said:

Hmm, no power brake Impala. 😉

 

Thanks Frank.... yeah, no power brakes, but it does have power steering... you figure for such a big auto, they would of added power brakes. To be honest, I didn't noticed the weeping, I guess the flash on my phone camera really highlights it !

 

Steve

 

20150911_094311.jpg

Share this post


Link to post
Share on other sites
6 minutes ago, lump said:

That is the taller style, but it might the correct original unit, if your car is late 1969 unit. Anyway, in the attached cropped piece of your photo, I have marked a flat-machined spot with the word "HERE" to show you where you may be able to clean away rust and find production date codes. 

Great !  Thanks Lump !

 

Steve

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this