C-1 Brake Question

[Vette66AirCoupe]

My '60 is diving to the right when I first hit the brakes so I pulled the front drums this afternoon for a look since the car is new to me. My first surprise was that the right front bearing was REALLY tightnen down hard, unlike the left front which seemed just snug. The second thing I noticed was the ball bearings. Hmmmmm. As this is the oldest car I've ever purchased, my first being a '65 Impala SS, I have no experience with these bearings. I've always tightened them down just snug and then backed them off to fit the cotter key in. So question #1 is what is the proper procedure for tightening the wheel bearings on a '60 Vette?
I was pleased to find that the shoes were dry and meaty. However, the left front wheel cylinder has a swollen rubber boot on it so I plan to replace both front wheel cylinders while it's apart. I'm hoping that when I'm finished bleeding and adjusting I've solved the problem. Question #2 is, are these wheel cylinders available over the counter at a NAPA type store or will I have to buy them from a Corvette specialty retailer? Question #3 is, are there any wheel cylinders available that are better for cars that log limited mileage? Question # 4 is a 2 part question, Is there any particular kind of brake fluid that I should use? I've heard that some fluids resist absorbing moisture so I'd like to know if any of you have switched to something else and if so have you flushed the old stuff out first? By the way, I plan on looking at the back brakes when I'm finished with the front. I'm working on the floor and only have 2 jack stands. Question #5 is what else should I be looking at closely while I inspect the brake system? Thanks in advance for any help you can offer.

 

[Rowdy1]

Oh John Z. ............

John Z. is the one you want to see this.

 

[old-hot-rodder]

If your hoses going to the wheel cylinders are not as new I would suggest you change them. 99% of the time when I see the older cars pull when hitting the brakes it is because of internal swelling of the brake hoses. Good luck.

Al Whittier
silver "59"

 

[JohnZ]

Terry - The ST-12 outlines the procedure for adjusting the (ball) wheel bearings - if you don't have the ST-12, you should get one - all the resto parts houses have it; it's the only GM Shop Manual ever printed for C-1's.

In short, here's the procedure:

1. Tighten the spindle nut to 33 ft-lbs. while rotating the wheel & tire (to seat the bearings), then back off the nut to loose, then re-torque to 12 ft-lbs.

2. Insert cotter pin if either the horizontal or vertical holes line up (there are two pin holes in the spindle); if neither hole aligns with a slot in the nut, back off the nut until the nearest hole and slot line up, and install the cotter pin. It will never require backing off the nut more than 1/12th of a turn, or half a flat, to align the next hole and slot.

The original wheel cylinders were 1-3/16" (front) and 1" (rear); the fronts haven't been available for years, but NAPA and the resto parts houses all have 1-1/8" direct replacements for the front and 1" replacements for the rear. If your fronts are original, you might consider having them sleeved, if you can find 1-3/16" rebuild pistons.

Brake fluid is a matter of personal preference - ordinary DOT3/DOT4 glycol fluid works fine, has been the industry standard for 80+ years, and should be flushed/bled every two or three years in order to eliminate the possibility of corrosion. DOT5 silicone fluid isn't hygroscopic (doesn't attract moisture), but it has problems all its own - it entrains air in microscopic bubbles when agitated that are nearly impossible to get out, is not compatible/won't mix with glycol-based fluid, and requires that the entire system be thoroughly flushed with denatured alcohol to remove any traces of the glycol-based fluid before filling with DOT5. Personally, I've always used DOT4 Castrol GT LMA (Low Moisture Absorption) fluid, flush/bleed every three years, have never had a problem.

If you're going through the brake system, replace the flex hoses - they deteriorate from the inside out (swell shut), preventing the reverse flow of fluid when you take your foot off the pedal, with no externally-visible abnormalities, and shed tiny bits of rubber into the fluid. They should be replaced every ten years - they're dated on the outside so you know how old they are (although that just says when they were made, not when they were placed in service).

 

[Vette66AirCoupe]

John,

Thanks for your very informative reply. Ironically I just ordered the ST-12 from Corvette Central this morning. I understand everything you told me except I'm a little fuzzy on one thing. How do you go about flushing out the old brake fluid? Is there a turkey baster involved here? I just put new stainless steel lined calipers on the front of my '66 and am now about to replace all of the wheel cylinders on my '60 so I'm all for keeping the moisture out of both systems. I'd really appreciate it if you would share the procedure you use with me. Thanks again, I really appreciate all I've learned from you and I'm not just speaking of this particular thread.

 

[Rowdy1]

See, What Did I Tell You?

John Z. is the one you want to see this.

Thanks John, even though I didn't post the original question, as always, you're amazingly informative. Ever thought about adopting a senior citizen?

 

[Toy4Hal]

Terry - The ST-12 outlines the procedure for adjusting the (ball) wheel bearings - if you don't have the ST-12, you should get one - all the resto parts houses have it; it's the only GM Shop Manual ever printed for C-1's.

John, what is the "ST-12"? I don't think I have that.

Thanks.

Hal

 

[JohnZ]

Hal, the "ST-12" is also known as the "1953-1962 Corvette Servicing Guide" (has "ST-12" in the lower right corner of the cover, the GM publication number). It's the '53-'62 Corvette Shop Manual.

 

[JohnZ]

Thanks John, even though I didn't post the original question, as always, you're amazingly informative. Ever thought about adopting a senior citizen?

I'm already a senior citizen - don't need to deal with another one like me

 

[JohnZ]

John,

How do you go about flushing out the old brake fluid? Is there a turkey baster involved here?

I haven't done it myself, as I've used glycol fluid for the last 40 years. If I needed to, I'd suck the old fluid out of the master cylinder, clean the reservoir thoroughly, fill it with denatured alcohol, and keep bleeding the system (and refilling the master cylinder) with alcohol until nothing but clear alcohol comes out of all the bleeders. Then I'd disconnect the line(s) at the master cylinder and blow the system out with compressed air (bleeders open), foot-pump the alcohol out of the master cylinder bore, on-car bench-bleed the master cylinder with the new fluid, re-connect the line(s), and proceed to fill/bleed the rest of the system, VERY carefully. Silicone fluid does NOT like pressure and agitation during fill/bleed, especially when filling an empty system where it's pushing air through the lines, and it may take a lot of time (and fluid) to get the entrained air out and get a decent pedal.

Seems like a lot of work to me for little benefit, but it's your call.

 

[Vette66AirCoupe]

Brake fluid is a matter of personal preference - ordinary DOT3/DOT4 glycol fluid works fine, has been the industry standard for 80+ years, and should be flushed/bled every two or three years in order to eliminate the possibility of corrosion. <<<<John Z

John,
I should have been more specific. I'm with you, the silicone fluid sounds like way too much trouble. What I was curious about was how substantially you flushed your brakes as per the above. Thanks again.