Right rear drum dragging

[Zymurgy]

I took Goldie out for a test drive, my 66 300, with converted 73 front disc. I have been getting a vibration in the rear right, the rear wheel bearings were changed.

After my drive I shot the temperature of each wheel at the disc or drum. Front rotors 150, left rear 115, right rear 190. I didn't get a vibration today but it is a beautiful cool upper 60's day. The brakes were completely overhauled 6 years ago, when they are cold the wheels spin freely so I presume they are adjusted correctly.

Would it be logical just to replace the wheel cylinder on the dragging brake? My brake pedal feels excellent.

 

[stubs300]

How old are they? How cruddy is the fluid? When's the last time it was changed? When's the last time you looked at, worked on, or inspected the rears?
I don't know, what do you think you may need as I don't know those answers.
Oh wait, you just did the rear bearings recently right?

 

[Davea Lux]

Six years is a fairly long time in the rust belt. Did you do the rebuild with conventional brake fluid or DOT 5? I suspect that if you used conventional fluid, you will probably need to change the rear wheel cylinders.

Dave

 

[Zymurgy]

Everything in the system looks fine, no leaks any where I did the disc conversion last year. The rear drums where removed just weeks ago, when the bearings where replaced. The rear brakes have 11,000 miles in 6 years.

The vibration has been around for a few years now, before it only occurred when I drove over 50 miles, which was usually only once or twice a year. Now it is 15 miles or shorter when it is hot.

I still have the conventional DOT 3 brake fluid

 

[Wollfen]

Everything in the system looks fine, no leaks any where I did the disc conversion last year. The rear drums where removed just weeks ago, when the bearings where replaced. The rear brakes have 11,000 miles in 6 years.

The vibration has been around for a few years now, before it only occurred when I drove over 50 miles, which was usually only once or twice a year. Now it is 15 miles or shorter when it is hot.

I still have the conventional DOT 3 brake fluid

Did you do the final lash tightening of the side play in the axle shaft?

 

[Zymurgy]

Did you do the final lash tightening of the side play in the axle shaft?

No I have not, could that play into it too?

 

[Wollfen]

No I have not, could that play into it too?

Yes it can, you shouldn't drive on new bearings with side play in the axles, they wont bed properly plus with a little side play which ever side is sticking out a bit more will be the side that will be off center, the axle shaft to the axle housing because of the weight of the car on it. Since it is only a two minute job, I beleive you should get the side play tightened up via the screw ring on the passenger side, then take it for a drive again.

 

[polara71]

Huh.... I never thought of that ....

 

[Zymurgy]

Thanks for the great advice, I should have done it immediately, but I just want to drive it and not work on it. I've learned my leason.

 

[1970FuryConv]

If none of that works, I've had problems with the parking brake adjusted a little too tight. For some reason, the right side drum gets smoking hot, but the left side stays relatively cool. You could try backing off the parking brake adjustment and see if that helps.

 

[Zymurgy]

If none of that works, I've had problems with the parking brake adjusted a little too tight. For some reason, the right side drum gets smoking hot, but the left side stays relatively cool. You could try backing off the parking brake adjustment and see if that helps.

Thanks for the tip. I never use my parking brake and don't honest remember ever adjusting it.

 

[mr. fix it]

A good mechanic will back off the parking brake before any adjustments on the rear brakes.
then after the brakes are setup adjust the parking brake cable.

 

[Zymurgy]

I need all the good mechanic tips I can get. Most of the stuff I have done is totally new to me. I really appreciate all the input.

 

[rags]

here's some trade school level stuff. primary and secondary shoes. primary goes at the front of the assembly. tops of the shoes should be seated against the pin when assembled. spreader bar for the e-brake should have free play, adjusted out later (mr fix it above). have had cheapie dot3 fluid in my cars forever and never had a leaking/frozen part. wheel cyl. pistons can rust in a non leaking cyl. with a damaged dust boot. smart move to check with a heat gun. when it was smokin' hot did you jack it and spin the wheels? smell asbestos?

 

[Zymurgy]

Thanks for the great info. I am going to go back through and the double check all the work I did 6 years ago. I screwed up other aspects of my brake work. I did not jack up the wheel and see if it would spin. I will make sure I have a jack with me next time.

 

[stubs300]

I should have done it immediately, but I just want to drive it and not work on it. I've learned my lesson.

Isn't that normally the case with everybody, myself included?

 

[rexus31]

I had the same issue with my right rear, Mike. It turned out to be the adjustment on the parking brake.

 

[Zymurgy]

I had the same issue with my right rear, Mike. It turned out to be the adjustment on the parking brake.

This is really starting to seem like the the culprit, since I have never used or adjusted them.

Hell I might make my mpg into the teens if I don't have a brake dragging.

 

[mr. fix it]

This is really starting to seem like the the culprit, since I have never used or adjusted them.

Hell I might make my mpg into the teens if I don't have a brake dragging.

Everyone is allowed to dream Mike...

 

[Davea Lux]

This is really starting to seem like the the culprit, since I have never used or adjusted them.

Hell I might make my mpg into the teens if I don't have a brake dragging.

If the E-Brake is dragging, you can check for that by setting jack stands under the rear axle so that the wheels are off the ground. This puts road weight on the rear suspension. Now take the car out of gear and try to turn the rear wheels. If the wheels turn freely, your e-Brake is not dragging. While you are at it, check for excessive end play in the rear axles. Pull out and push in on one of the rear wheels, if you hear a clank or fell a lot of movement, you have excessive end play. Should only be about three thousands of an inch.

Dave