ZRace XG calipers- how do you bleed?

Started by Takiyaki, September 17, 2024, 08:48:18 PM

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00Garza

Quote from: jonathanf2 on September 19, 2024, 01:38:24 PM
On AliEx, you can get a pair of Shimano GRX 400 calipers for slightly more than a pair of ZRace XG calipers. Way better performance and easier to adjust overall.

https://www.aliexpress.us/item/3256805058833940.html

Nice. I might replace my Ltwoo calipers with this. Rear brake has been giving me trouble.

rtuk

Quote from: jonathanf2 on September 20, 2024, 04:46:04 PM
Clean the rotors with alcohol or acetone. Torch them for a few seconds with a flame to burn off the mineral oil. Sand them down with a fine grit sound paper to rough up the surface.

For the pads you can just torch them and sand them and they should be useable again.

Re torching the rotors & pads - would a heat gun provide a similar benefit?

I'm guessing no - as you need the flame to consume the organics in the mineral oil, but as I dont have a torch / do have a decent heat gun - it'd be useful to be sure.

Ludo

Brake cleaner from at auto store should do the trick

jonathanf2

Quote from: rtuk on September 21, 2024, 03:57:00 PM
Re torching the rotors & pads - would a heat gun provide a similar benefit?

I'm guessing no - as you need the flame to consume the organics in the mineral oil, but as I dont have a torch / do have a decent heat gun - it'd be useful to be sure.

I have a gas stove, I just use that. Once you see slight smoke, the mineral oil should be cooked.

Takiyaki


dsveddy

After suffering my own adventures bleeding these calipers, I want to reiterate precision6625's advice. You need to directly bleed the caliper, especially on the rear wheel where the caliper's orientation will trap air at the top.

To do this you need a good bleeding syringe and an adapter that fits the ZRACE caliper bleed port. I'm guessing it's an M2 thread? Bleed port adapters that fit are hard to find. I use the funnel adapter with the smallest thread available in EZ MTB's 10 piece plastic adapter fitting kits. I jam the open tube end into the opening where the funnel normally goes. The diameters match up perfectly and create a seal. I believe if you have the brass kit you can put the funnel on and jam the tube into the funnel opening.

From there you pull on the syringe to pull out air and push mineral oil back in--if you're familiar with SRAM's bleeding procedure it will be similar.

Like precision6625 said, Hope's instructions are a good description of the steps if you are unsure.

1sanglier

Which block used for this caliper ?
Thanks

Unknownftp

Quote from: Takiyaki on September 20, 2024, 04:15:34 PM
I did a proper bleed and it's much better. I think I wrecked the front pads/rotor with mineral oil though. Back brakes have way more grip than front. But those Hope instructions were really helpful.

I corrupted mine a while ago, I let them sit submerged in brake cleaner. Then used drywall sandpaper since it lets the sanded particles fall through, then bit of flame to get any residual out.

Been using those pads for the last 300 or so miles, no issues.