What is a brake spacer…

[brian heidt]

Hi guys,
so just finished the annual on my pacer, in which we replaced tires, tubes, disks and pads. All same size as before (Cleveland 40-28 wheels, 30-18 brakes). Used rapco as indicated in spruce cat. Right tire felt tight, but mechanic said if you can turn by hand it’s ok and will loosen with wear. Well, it was pulling going out to runway, and felt like it stuck just at liftoff. Landing was fun (thank God for grass runways!!), and it turned blue getting back to hangar (stopped many times to let it cool). So now mechanic says I need a “spacer”. Don’t see that in parts cat. Shim seems different, this is pads rubbing on disk, not tire. any ideas??? Thanks brian

 

[Steve Pierce]

Those wheel and brake caliper part numbers don't ring a bell. I would first look at the 337 form filed for installing those brakes and then I would look at the illustrated parts break down from Parker Hannifin (Cleveland). Sounds like you have the wrong brake disc for the caliper unless you have bigger tires and the tire is rubbing on the brake caliper.

 

[Steve Pierce]

Did these brakes work fine prior to this recent work?

 

[Pacer42Z]

The brake pads should be "floating" on the brake anchor bolts so they can adjust for wear and move away from the disk after braking. Have you checked to make sure they are not binding? Also the brake piston has to move back after applying the brakes, have you checked if they move freely? I can move mine away from the disks by pushing the brake pads against the brake piston and the wheel will rotate free.

Juergen
Pacer N3342Z

 

[brian heidt]

Thanks for the replies
the plane was converted via Univair STC. No other documentation. The piston moved freely when it was put back together. I will check today when I take the wheel off to see if anything is binding, Juergen. Thanks. Steve could see anything called a spacer in that parts breakout. Brakes worked, but the disks measured too worn so they were replaced. I use brakes too much. Will check with mechanic on the name if what he wants. I thought maybe put the old partly worn pads on and see.
brian

 

[Steve Pierce]

Is the tire rubbing the wheel or the brake pads rubbing the discs. Do he ouch the pistons back into the caliper? Should be plenty of clearance from new disc and pads all the way to worn discs and pads. Silicone spray on the torque plate pins as well.

 

[sierrasplitter]

Brake spacers are used between the wheel and the disc to move the disc away from the tire . They are needed when you go to a large tire -26 inch Goodyear’s , 29 and 31 inch Bushwheels ect . They won’t do anything for a tight caliper . It’s no different than a car or bike brake . As said you need the caliper to “ float “ . Sounds like your pads are too thick .

 

[Jspey]

30-18 caliper and 40-28 wheel are the Colt brakes. I only recognize them because I'm looking for some.

 

[stevesaircraft(Bri)]

Brakes worked, but the disks measured too worn so they were replaced.
brian

Did you use the correct disks... There are thin and thick disks out there and if you replaced them with the thick disks that would explain the issue..

Brian

 

[brian heidt]

Did you use the correct disks... There are thin and thick disks out there and if you replaced them with the thick disks that would explain the issue..

Brian

Brian, that could be it. I cut safety wire and started loosening the bolts and with half a turn the wheel was spinning freely. Why only the right side I don’t know. So it is a disk, pad issue and I didn’t know disks came in different thicknesses. When I bought them just hit 2 on quantity so both sides will be same. Will ask mechanic to buy whatever part he wants. As to the brakes being colt… it’s been that way for 40 years and I’m not waking sleeping dogs. Thanks again for the input! Brian

 

[brian heidt]

Just to let you all know, my plane is flying again. I do believe the new rapco disks and Cleveland pads were just enough off that they bound a little and heated up causing the brake to lock. Cleaned , silicone sprayed the torque pins, and added 3 layers of aluminum tape the the inner “spacer” between the 2caliper halves. Spun freely, taxi tested and didn’t heat up. Took off and didn’t pull right. So good, then I remembered that the left caliper had been replaced a couple years earlier and the newer version didn’t have the center piece but that was cast on the outer half. Mystery solved, old and new just 3 thousands different.