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TR2/3/3A TR3A caliper rebuild

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Dan_Pasta

Dan_Pasta

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The fed-ex guy brought my new pistons and rebuild kits last night so I’m about to rebuild the brake calipers on the TR3A. The only problem is the rebuild kit has the dust boot, the seal, and a circular piece of wire looking “thingy”. I know where the seal and dust boot goes … but the wire thingy has me baffled. I’m no stranger to “extra” leftover parts after one of my assemblies, it’s just with something as important as the brakes I’d hate to leave something important out. I’d hate to think I needed to run into a wall and scratch up my paint job every time I had to stop.

Can anybody tell me what the “thingy” is for?
 
There were two different styles of dust boot, one of which went inside the caliper bore with an outward lip that fit into a groove inside the bore to retain the boot to the caliper. The other style of boot fits over the outside of a protrusion from the caliper casting, and the wire thingy works like a clamp to help retain it.

Originally the dust boots were different moldings, but I wouldn't be surprised if some clever engineer hasn't decided that the same boot can be used on either caliper, by leaving out the wire thingy.
 
Are these front calipers or rear wheel cylinders?
 
Description sounds like front calipers.
 
Dan_Pasta said:
The fed-ex guy brought my new pistons and rebuild kits last night so I’m about to rebuild the brake calipers on the TR3A. The only problem is the rebuild kit has the dust boot, the seal, and a circular piece of wire looking “thingy”. I know where the seal and dust boot goes … but the wire thingy has me baffled. I’m no stranger to “extra” leftover parts after one of my assemblies, it’s just with something as important as the brakes I’d hate to leave something important out. I’d hate to think I needed to run into a wall and scratch up my paint job every time I had to stop.

Can anybody tell me what the “thingy” is for?
Click to expand...
It would seem you got the wrong kit. The wrong kit has the retainer ring and the lip of the dust boot that goes on the piston is too big for the small thin groove in the piston.

If the vendor sent the wrong kit, they may have sent you the wrong pistons which should have the thin groove. Compare to your old ones. If they sent the wide groove pistons to match the dust seal, the dust seal still wont be able to be held on, as there's no boss on the OD of the caliper bore for the ring to snap onto.

You should have a kit with some reference to Girling part number SP2501 and the pistons should reference 64325561. A lot of newer aftermarket companies get it wrong.

Peter C.
 
Just finished rebuilding the first caliper and everything seemed to go together smoothly ... I'm saving the extra "thingies" in my toolbox just incase I'm a "thingy" short on some other project ... ya never know. Thanks for the help everybody.

On a side note ... if it's too hot to do the repair in the garage, and you decide to rebuild the calipers on the kitchen table ... no matter how well you think you have laid down "protection" the cost of a caliper rebuild may include buying an irate wife a new kitcken table because some brake fluid finds its way to the table top.
 
Dan_Pasta said:
On a side note ... if it's too hot to do the repair in the garage, and you decide to rebuild the calipers on the kitchen table ... no matter how well you think you have laid down "protection" the cost of a caliper rebuild may include buying an irate wife a new kitcken table because some brake fluid finds its way to the table top.
Click to expand...

Or, you can install an AC unit in your garage. It's made my life SO much nicer!
https://www.theymightberacing.com/ShopTech/AirConditioning.aspx

Jody
 
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