Brake Problem...

4x4M38 · Post by **4x4M38** » Mon Jan 19, 2015 11:28 am

Hi Wes,
I appreciate all of the advice given and plan on getting this vehicle to a shop to have the brakes and steering checked out professionally once I have them installed and operating, and before I try and license it for the road.

I do completely understand your position in giving advice and it is taken with the knowledge that I am completely responsible in the end and should have everything professionally checked that I do not have complete confidence in.

The shoes are new. The brake drums are not. I had very little if no ridge, and the surface was in very good shape, so if they were skimmed it was minor. I adjusted the shoe/drum clearance for .003 on the bottom, and .008 on the top. I was able to maintain the feeler gauge clearance both top and bottom once adjusted. Because of that I assumed at that point that if there was any radius issue it was minor. I may be wrong.

What would be a proper shoe break in or running in procedure?

I also double checked the pedal free play this morning and at the pedal it is right at 1/2". How do I check for cylinder travel only?

Just to be clear, the brakes are not applied or dragging all the time, they just feel like they are not stopping in the distance I think is right. In the end you may be right on the money, in that they just need to be broken in.

Tks,
Brian

4x4M38 · Post by **4x4M38** » Mon Jan 19, 2015 2:12 pm

Well RickG brought up an interesting point.

It has been decades since I drove anything without power steering and power brakes.

I rolled the jeep down the driveway this morning dead stick. I used the service brake to stop it. It stopped, but with some effort to push the pedal down. However, it did stop. The pedal went about 1-1/2" after pedal free play then stopped solid. At that point, more foot pressure slowed the roll and stopped it.

As Wes puts it maybe I'm over analyzing the brake feel.

It just very well may be a function of the shoes needing break in as well as a lack of power brakes and a totally different feel.

Thanks,
Brian

RICKG · Post by **RICKG** » Mon Jan 19, 2015 3:43 pm

Take home message:

1. Everything Wes stated above is key to proper operation and SAFETY.

2. Your properly adjusted and maintained brake system will not have the
same feel as your modern power ABS system.

ChuckW · Post by **ChuckW** » Mon Jan 19, 2015 7:51 pm

Back in the day, if you installed new shoes into a worn drum, you had to have the shoes "cam ground" to match the radius of the drum, or else you would only have small contact areas between the drum and the shoe. If not "cam ground", the shoes will eventually "wear in" to match the radius of the drum, but until that happens, you may not have much brakes. And remember, you are dealing with a 9" brake, that's pretty small.

Post by **wesk** » Mon Jan 19, 2015 11:47 pm

If the drums are not new then you MUST mic them and for the amount of oversize you must shim the shoes accordingly. Also any ledge has to go. It will only give you grief along the way. Find an old drum lathe and get them turned round and smooth. Yes it is a PITA but if you want decent used drum brakes you have to start with correct setup. So if drum ID mics to say 9.12 then your drum is worn 0.12 so you want to install 0.06 shim stock in between each shoe and it's lining. Then after initial set-up and adjusting. Determine contact area of shoe to drum with pedal applied. If you have about 2/3 rds or more of the shoe's surface snug against the drum I would settle for that. But if you have 1/2 or less then the cam grinding is the next step.