wheel locked up

[AustHaflinger]

Yes the wire method works really well - used it the last time I did my brakes - but I cannot remember just now, it is on the forum somewhere.

[ogdenenterprise]

After fitting everything back together and bleeding the brakes, I thought I would give the haf a little run.
I tried to reverse out of my shed, but I found that the same drivers side rear wheel was locked up again.
I removed the wheel and found the drum was locked up, but with a bit of tapping I got it off. I took the
drum to a friend of mine who has a lathe, I picked it up last night, he said he had skimmed it as it was slightly out of true.
I haven't had time to re assemble it yet, but I will keep you posted on the result.
Just as a after thought, what makes the drums go out of true??

Dave

[heinkeljb]

Someone stamping on the brakes to hold the vehicle stationary after normal braking which gets the drums hot.

Make sure you gout the brake shoes in the slots in the pistons and the top of the brake shoes are in the slots of the little hardened pins slots. Those pins can fall out.
Did you back the adjusters off all the way before deciding you needed the drum skimmed? The adjusters are not the best designed part of the Haflinger! Maybe your brake linings are a little too thick? Did you remember to put a chamfer on the leading edges of the brake lining?

John

[ogdenenterprise]

I checked both of the shoes were in the correct position and the adjusters were not holding the shoes out. I will hold my hand up and admit I
didn't chamfer the edges of the pads. when I refitted the wheel I spun the wheel in both directions as I had both wheels jacked up, the problem drum seemed to catch slightly but it still turned. I didn't try to move the Haf till the next day, that's when I found it was locked up again.
I will check to see if there is any chamfer and put one on if there isn't. Its going to be Monday before I can check it, I have to work this weekend.

Dave

[ogdenenterprise]

As the old saying goes, as a last resort read the instructions. I got some replacement springs for the shoes, they match the smaller diameter one in the photo. I thought all good everything is new, but when I tried to put the drum on it was still catching and when I tightened the wheel up it locked again.
I tried the drum without the shoes and fitted the wheel, everything was ok. so I thought as a process of elimination it has to be the new linings on the shoes. That is when I got the repair manual out and measured the thickness of the pads. I compared them to the manual measurements and found they were nearly 1mm too thick. I found some old shoes that had 3.5mm pads on compared to the new 4.8mm ones that had been fitted to the shoes.
The imperial/ metric conversion in the manual says 3.9999mm maximum, so I have fitted the older ones. finally problem solved.

Dave

[AustHaflinger]

That is great to hear. Who did your relining of your brake shoes - they should have discussed whether you wanted standard or oversized linings. Normally you would take a brake drum with you which they would measure and provide advice.

Looks like the project is coming close to be finalised - but it never ends.

Garry

[ogdenenterprise]

Hi Garry,
I took it to a local brake shop, they asked me if I wanted the pads the same or thicker. I said the same, but I think this has been the problem from the start, this particular wheel has always grabbed when I reversed, so I would drive forward about a meter and it would free it self. I didn't change the shoes on the rebuild because the looked good. anyway you live and learn everyday.

Dave

[heinkeljb]

You could always try a different drum with those shoes. Drums wear and the internal diameter gets bigger. So maybe those shoes will fit or maybe you will have to look into the best way to reduce the linings by a mm. Probably the best way would be to get them relined with a thinner liner. Don't forget to have a chamfer on them. Drum brake shoes like those!

Nice to hear you solved the issue.

John