Allcoupedup

Lost the front brakes in the fall after a highway trip and trying to determine what went wrong.

No leaks and when I blead the front brakes I achieved a firm pedal. Is it possible for loose front bearings to cause caliper "pump up" like it is on the rear bearings? I do have a shimmy that feels like pretty bad wheel imbalance >55 Mph.

I'm not quite sure how to measure bearing run out. While the shop manual says .001 -.008 end play and zero preload, I'm not sure how to measure it.

Measurement 1:
base of dial gauge on the caliper, head of dial gauge on middle of rotor surface. After a full rotatation, each rotor was .005 maximum run out.

Measurement 2:
base of dial guage on the caliper, head of dial guage on middle of rotor. Grabbing rotor and pulling top, pushing bottom at 90 degree rotations produced a max "play" of .013 and .022 for the fronts. There is play I can feel so I'm guessing these bearings are shot.


My questions:
- Is it possible for loose wheel bearings to cause air to be introduced into the system
- Where is the right place to measure - where should I place the head and base of the dial gauge?
- Can these bearings be adjusted?
- I understand the concept of "zero preload" but how does one achieve it


Want to make sure I am correctly diagnosing the problem before ripping apart the bearing assemblies.

Thanks,
brian

Dan Hampton

I would forget the dial indicators and pull the front hubs and inspect the bearings although I don't think that is your problem with braking. If you have a shimmy, bad bearings could be the culprit, though, assuming you have ruled out a bad wheel.

While I was replacing my front pads and rotors on my '67 a month or two ago, I disassembled the bearings on both hubs. Both of the outers were pretty well gone and one of the bearings had "worked" the race on the outside so that it had spun in the hub. From a driveability point of view, the car had no issues.

Mine is a 68,000 mile car that was well maintained. You need to do a visual on both hubs and see if they are in need of replacement. I would do the "drill", as the maintenance on these are overlooked much of the time. It is a ten minute exercise.

Allcoupedup

Pulled the KO adapters and the dust caps and noticed that the nuts were not tight so I pulled everything apart.

Nothing is scorched or pitted or destroyed but this is the first time I've ever had a bearing apart. Here are the worst shots - I had a hell of a time getting my camera to focus and the flash really makes things look worse than they do with the naked eye.

What do you think?

Spindle - I can't feel any of these marks with my fingernail but when I run a razor blade across it, I can feel scratches.




Bearing shots
Looks dirtier with the flash


worst mark - races look pristine



This car has unknown miles (estimate 110k) and one side had Timken and the other side has a differnet brand so somebody has been in here before. Neither bearing was making noise.

I'll probably run out to the store and get some seals and a greaser tool and put everything back together. With proper nut torque everything will be much better. Found a loose caliper bolt too (this is my first time removing front rotors since I've owned the car).

Thanks,
Brian

MikeM

Hard to tell but your second and fourth pictures look like you have a problem with a spun inner bearing.

I'd tell you how to fix that but I did that once before here and two guys got all uppity with me and I think they must have wound up having a stroke or something as I haven't seen them on here in a couple years. One of them was a injuneer or something like that.

Have somebody that knows what they're looking at check your spindle and hub out that you have pictures of here before you put it back together.

In regards to the loose bearings causing your brake problem, don't think so but I know there's a world full of people out there and some will disagree. Lift your calipers off the spindle and see if you see any damp spots of fluid. If you do, repair/replace the calipers.

Mr D.

Is it possible for loose wheel bearings to cause air to be introduced into the system

No

Where is the right place to measure - where should I place the head and base of the dial gauge?

Not sure what measurement your trying to take.

Can these bearings be adjusted?

No

I understand the concept of "zero preload" but how does one achieve it

I tighten the spindel nut down to seat the bearings and than it back off to align the cotter pin hole. Some might disagree with this method but have always worked for me.

Mossy66

Since you have everything apart, and you don't know how long those wheel bearings were in there, I would replace them. Even if the bearings you have look OK, they are not expensive, and you probably won't have to worry about them ever again.

I doubt that the bearings would be the cause of a shimmy though.


Gerry

jim lockwood

I'll defer to others with more experience on C2 disc brakes on the question of air introduction.

It is possible for loose bearings to cause the rotor to knock the pistons back in their bores. This will cause the perception of no brakes because the first depression of the brake pedal does nothing more than push the pistons back into contact with the rotor.

It's hard to say if the axial play you measured is enough to cause significant knock back, though.

Best to change the bearings while you have everything apart, adjust the new bearings properly, and see what happens.

Jim

MikeM

The "adjustment" method is described in the '63 service manual. I just don't believe I'd try to "adjust" my way out of a problem with the parts I see here based on what I think I see in the pictures.

Dan Hampton

One of the issues that occurs when a hub becomes loose is that someone will try and torque down the castellated nut to remove the slop, thinking this is the adjustment. What they are doing is working that race even harder (grease is probably long gone) which just exacerbates an already existing problem.

I agree with Mike. Have someone check that spindle before you put new bearings in the hub. I have seen worse and it is sort of a judgement call. It would be better if we could feel that spindle as opposed to viewing it.

Dump the old bearings. New inner/outers/races and seals will run you all of $50. Check for leaks re: the brake fluid.

Allcoupedup

Thanks for all of the information guys. I found some new seals and put it all back together with the old bearings. After hearing all of the horror stories about setting up the rear bearings I think I was overcomplicating the fronts. Literally, tighten will turning the wheel, torqure to 15 ft-lbs and put the cotter in. Easy enough for me.

After reading these posts I really feel like a bubba for not using new bearings. Now that I've been through a removal, cleaning, and reassembly it will be easier next time. Plus, this car will probably see only 5-10k miles in the next 10 years so there is plenty of time to do it right.

The play I felt before is now gone. Doubt this will solve my brake problem but it needed to be done.
Learned a lot today
Brian

Mr D.

While I agree there is a procedure in the 63 service manual called "Front Wheel Bearings-Adjust" all your really doing per the manual is tighting the spindle nut to 15 ft lbs and backing it off to insert a cotter pin. To have a ture adjustment of something there needs to be a +/- measurement to work off of and in this case there is not.

Mossy66

Actually, after you tighten while spinning the wheel, you are supposed to loosen at least a flat on the nut and put the cotter pin in.

Dan Hampton

Although you already reassembled it, I hope you were able to use a grease packer like the one listed below.

http://www.amazon.com/Lisle-34550-Ha.../dp/B0002NYDYO

toddalin

Did you pull those bearings out of there looking like that?

I certainly hope that you didn't put them back in looking like that.

Those are way too dry. The pink/red grease should be packed in there really thick.

MikeM

Yep! If that's the way you did it, you are asking for trouble!

I think you might be anyway after looking at your spindle and bearings. Didn't see the hub.

Westlotorn

I see the note where you torqued to 15 pounds but I dont see where you backed off before putting the cotter pin in. If you don't install a little play to allow for the bearings to grow as they heat up you will have wheel brg failure. That is why the guys mention backing off one flat of the nut.
Another way to adjust is by feel. Tighten the nut till the washer is tight against the bearing. Loosen the nut till you can move the washer with a flat blade screw driver, you should be able to get the washer to slide side to side slightly when the nut is properly tensioned. The movement is slight, maybe 1/16 of an inch each way but it should smoothly slide but you should feel the slight drag from the nut tension. This method eliminates any issues with threads causing bad torque measurements. If the washer moves with just a little drag on it you are not too tight. Before tensioning the nut move the washer a little to see how much play to expect when you set your torque.
When I was new to the Automotive industry an old mechanic showed me this tip. It has worked for 35 years for me with many trailer and auto bearings installs.
When you installed the bearings on the hub the inner bearing should have fit tight on the spindle. If it was loose it has been spinning on the spindle and needs to be repaired.
Your picture does make it look like you had a inner bearing spinning on the spindle but it does not appear to have blackened or blued the shaft.

Allcoupedup

I packed them good by hand before putting them back in. Squished plenty of grease into the rollers.

No I did not back off one flat. Looks like I need to take things apart again. KOs (spinners and adapters) are starting to drive me nuts.

thanks again for the advice
Brian

Allcoupedup

Anyone have the timken part numbers for outer and inner bearings and seal? If I have to take all of the crap off again I might as well do the job right.

Seals cost me $10 each at Autozone today. I see Zip has a kit for $33 per side but I'm not sure I want mystery bearings.
Brian

SupremeDeluxe

Brian,

I am doing this now myself on the 435 car. I have an extra set of bearings (USA Timken) if you need them.

The issue most fail to address with the front brakes on these cars is lateral runout after front rotors are replaced. The original hub/rotor was machined on the bearing axis after the hub and rotor were riveted together. Typically the surface of the hub where the rotor mounts is so far out of square to the axis of rotation that a significant lateral runout condition results and that is what will cause a softening pedal over time.

The only solutions are to either shim the rotor to achieve less than 0.004" lateral as measured with the bearing preloaded (no end play) a a point one inch inboard of the rotor OD, or to machine the rotor as an assembly (less reliable).

Nick

Dan Hampton

These are pretty standard bearings. Just ask your AZ counterman to look them up by application. You don't need numbers.