'59 Drum Brakes - prim/secondary springs

[Robert C.]

Re: '59 Drum Brakes - prim/secondary springs

Frank..........launched one spring across the shop. So yes, eye protection is important !

[Steve G.]

Re: '59 Drum Brakes - prim/secondary springs

yes, I have the proper tool. Let me put it this way, the rear spring was so strong I needed a guy to hold onto the frame. Body is
off, only the read axle and front suspension are installed.

The springs are grey in color.

The thing that threw me was the one longer spring someone installed in the past.

I will post pictures tomorrow night. It's a good 1/4 inch longer, maybe more.

If you needed someone to hold the car down while you put a brake return spring on, you've got the wrong spring.

Steve

[Steve G.]

Re: '59 Drum Brakes - prim/secondary springs

Or you have the right springs and the wrong shoes (holes in the wrong place). I wouldn't rely on the color of the springs. There is no universal coding and every spring manufacturer supplies in a different color.

Steve

[Mike E.]

Re: '59 Drum Brakes - prim/secondary springs

Something is not right. Only a moderate amount of effort should be needed.

[Richard M.]

Re: '59 Drum Brakes - prim/secondary springs

Steve, I have sent you a PM.

Here are the springs that have given me trouble. They were the wrong springs. That is why I couldn't get them on easily using the tool I've used forever. Which BTW, I know how to use.

I bought these from my supplier several years ago, and got 2 car sets and used one set. I just took the spare set off the shelf and measured. The wire size is a bit larger, 0.105 on originals vs 0.110" on these H131's, and they are 0.200" shorter than the originals. Shorter made it harder to install.

THAT was my problem. I looked it up and the H131 is NOT for Corvette. It's for Chevy trucks and other marques.

My Corvette parts supplier sent me the wrong parts, and also to others at that time.

Clearly I made a mistake at the time, not measuring the differences of the springs when I had trouble installing them.

Robert, You may want to measure your springs for reference. Where did you get them? What Part# and application?

Original types on either side of the bagged replacements.
P3020024.jpgp3020025.jpg

P3020026.jpg

Original type
p3020027.jpg

Replacements
P3020028.jpg P3020029.jpg

Length difference.
P3020031.jpg


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[Steve G.]

Re: '59 Drum Brakes - prim/secondary springs

Steve, I have sent you a PM.

Here are the springs that have given me trouble. They were the wrong springs. That is why I couldn't get them on easily using the tool I've used forever. Which BTW, I know how to use.

I bought these from my supplier several years ago, and got 2 car sets and used one set. I just took the spare set off the shelf and measured. The wire size is a bit larger, 0.105 on originals vs 0.110" on these H131's, and they are 0.200" shorter than the originals. Shorter made it harder to install.

THAT was my problem. I looked it up and the H131 is NOT for Corvette. It's for Chevy trucks and other marques.

My Corvette parts supplier sent me the wrong parts, and also to others at that time.

Clearly I made a mistake at the time, not measuring the differences of the springs when I had trouble installing them.

Robert, You may want to measure your springs for reference. Where did you get them? What Part# and application?

Original types on either side of the bagged replacements.
[ATTACH=CONFIG]58949[/ATTACH] [ATTACH=CONFIG]58950[/ATTACH] [ATTACH=CONFIG]58951[/ATTACH]

Original type
[ATTACH=CONFIG]58952[/ATTACH]

Replacements
[ATTACH=CONFIG]58953[/ATTACH] [ATTACH=CONFIG]58954[/ATTACH]

Length difference.
[ATTACH=CONFIG]58956[/ATTACH]


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Rich, I sent a reply to your pm. Hopefully it will help us reach an understanding on this subject.
Steve

[Richard M.]

Re: '59 Drum Brakes - prim/secondary springs

Rich, I sent a reply to your pm. Hopefully it will help us reach an understanding on this subject.
Steve

Thanks Steve. I read it and replied. I hope we can resolve our understanding as well.

Rich
p.s. Robert, don't leave us now. How did you do? Can you get a measurement of that trouble spring?

[Gene M.]

Re: '59 Drum Brakes - prim/secondary springs

I install the upper springs prior to the shoes being clipped in with the compression spring, cup, and nail pin. Then I just swing in and push in the shoe against the backing plate and then install the cup, and nail pin.

No need to fight the spring, use leverage as your friend.

[Robert C.]

Re: '59 Drum Brakes - prim/secondary springs

Sorry.....work gets in the way sometimes.

Fronts are done, rear I tried several spring kits.

Raybestos H7019 worked ok up front.

I have a Powerstop kit from Summit Racing, Summit p/n 7018K.

Picture attached is the one longer spring I found when taking things apart

DSCN7542.jpg

[Robert C.]

Re: '59 Drum Brakes - prim/secondary springs

Steve,

I compared the shoes/holes to the old ones on the car, holes are in the same place. I thought about that too....

[Robert C.]

Re: '59 Drum Brakes - prim/secondary springs

Steve, the longer spring came from ?

[Steve G.]

Re: '59 Drum Brakes - prim/secondary springs

Steve, the longer spring came from ?

Another car?

If the distance from the hole in the shoe to the pin is the same, so should the spring. No shoe requires greater return tension than the other. Brakes with self adjusters use different lengths because they attach into the adjuster linkages etc. But all take about the same amount of force to install them. One hand and a fairly easy pull with the tool I pictured.
Steve

[Robert C.]

Re: '59 Drum Brakes - prim/secondary springs

Thanks Steve.

Got 3 of of the 4 brakes done today, along with the front hub assemblies.......

With the same length springs.

Backs (to me) seemed harder than the front springs. Then again, frustration plays a part of this too.

Thanks for your help (everyone's help).

It's slowly getting there !! "this close" to being a "roller"

Bob

[Joe L.]

Re: '59 Drum Brakes - prim/secondary springs

Thanks Steve.

Got 3 of of the 4 brakes done today, along with the front hub assemblies.......

With the same length springs.

Backs (to me) seemed harder than the front springs. Then again, frustration plays a part of this too.

Thanks for your help (everyone's help).

It's slowly getting there !! "this close" to being a "roller"

Bob

Bob------



I'm getting into this a little late here but here's what I can offer:

Attached are photos of GM brake spring kit GM #3981995. This is a SERVICE spring kit applicable to 1953-62 Corvettes. It is supplied to SERVICE one wheel. The two long springs, the subject of your original question, APPEAR the same, except for color. They are both exactly the same length at 5.12" total length. They both have 20 coils. They both have exactly the same configuration of the extensions on either end of the coils. However, they are NOT the same. The red painted spring has a wire diameter of 0.100". The green-painted spring has a wire diameter of 0.107". That may seem like a small difference but it makes for a significant difference in the tension the springs exert.

I feel pretty confident that the difference in the painted colors of the springs is intended to denote the differences in the springs which, otherwise, is pretty visually subtle.

The GM #3981995 was discontinued without supercession in November, 1986.


DSCN3101.jpgDSCN3102.jpgDSCN3103.jpg

[Dennis C.]

Re: '59 Drum Brakes - prim/secondary springs

While I have never seen similar information specific to Corvettte, the 1961 Passenger Service Manual indicates that the "brake shoe release springs are color coded for identification".

The secondary spring is colored black with a spring rate of 50 lbs and the primary spring is colored gray with a spring rate of 40 lbs.

Dennis