Alternative to crappy AT545 Drum Brake?

[Whitworth]

Hey Folks,

Would love some input on potential alternatives to the AT545 Drum Brake? I've had to replace shoes twice in the last year (I'll admit sometimes due to driver error) but I still feel like the drum brake should be holding up better than it is. Perhaps a disc brake could be installed somehow? I'm also open to upgrading the transmission altogether perhaps one with a locking torque converter and better parking brake.

Cheers

 

[s2mikon]

Finding a transmission with a transmission mounted parking brake is like looking for a spotted unicorn. It was common on the 500 series because that was common in medium duty trucks at the time. Manual or automatic. We have moved on.

 

[Whitworth]

If I was able to find a spotted unicorn any suggestions on best upgrade from the 545? Or do I just keep putting in new pads every 6 months?

Finding a transmission with a transmission mounted parking brake is like looking for a spotted unicorn. It was common on the 500 series because that was common in medium duty trucks at the time. Manual or automatic. We have moved on.

 

[s2mikon]

If you are replacing the shoes every 6 months there is something wrong. It could be that there are some worn mechanical parts causing you to adjust it too tight and dragging the shoes causing them to prematurely wear them out. During the era of tranny mounted parking brakes, some were drum type and others were outside band types. The band types worked better. I have had both. These are mechanical brakes like model A fords had and the parking brakes of the Jeep CJ-5 from the 60's. The mechanical parts inside can't be loose and worn out because of the mechanical ratios used. I have one of the band type on a 1600 cornbinder behind a 500 series Allison and it works good enough that I can't drive through it unless I floor it.

 

[ewo1]

There are options. I remember when I was younger, I drove a wrecker that had a lever on the floor that set the parking brakes, rear wheels, to lock.

Your gonna have to modify and adapt something but it can be done. Here are some examples of what is available.

VB Parking & emergency brake valves | Poclain

Range of pressure reducing valves that can be mechanically or electrically operated for static or emergency braking (SAHR).

poclain.com

VB3-002 - Parking & emergency brake valves - Poclain Hydraulics

VB3-002 is a reverse modulating (negative), mechanically operated brake valve for Spring Applied Hydraulically Released (SAHR).

poclain.com

 

[ewo1]

deleted-wrong thread...

 

[Mr P]

Those "brake valves" simply hold the normal brakes "on"...by maintaining system pressure. AFAIK, those have never been used on passenger vehicles. Why? Two reasons come to mind. First, there is no redundancy. Second, imagine parking on a hill....with a terribly slow brake fluid leak. Minutes or hours after parking....and the brake system loses enough pressure that the bus rolls.

Bad idea for "emergencies", and bad idea for parking.


Fix the problem with the existing parking brake....it should last for years of daily driving.

 

[Mr P]

If you are replacing the shoes every 6 months there is something wrong.

^ Yep.

 

[s2mikon]

I had mico locks on my tow truck and they were used when doing recoverys like from down in a ravine. I never trusted them because if a flex hose or wheel cylinder cup failed you were toast. I had four large rubber wheel chocks that I always set just in case. That being said I would test mine from time to time leaving them locked for a few hours and put it in gear and see if it would move. Most of the time it was good. Some time it would leak internally just enough.

 

[Whitworth]

Thanks for all the replies. Obviously I will continue to chuck the wheels but it sounds like this is going to be a shop expense and maybe a complete rebuild because of other worn parts that are destroying the pads. Oh well definitely worth having.

 

[Mr P]

I have a complete 545 parking brake assembly, was functional when removed. I'm in W KY. Where in MO are you?

 

[Whitworth]

Oh wow that would be perfect. I am in Saint Louis but could easily drive to you. Parts for this parking break are crazy hard to find correctly and last time I took it to a shop they said they couldnt find the right pads and still charged me nearly 3k.

 

[s2mikon]

3K to fix a parking brake?

 

[ewo1]

they couldnt find the right pads and still charged me nearly 3k.

WHAT ??? 3k???

Holy moly!

 

[s2mikon]

If my wife saw that she would make me go out of retirement and specialize in parking brake repairs.

 

[Mr P]

So, I vote you figure out why your brake shoes wore out, IF they did, before putting more parts into the dumpster.