Levo Gen 2 SRAM Guide RE problems

[2cool2fool]

Brand new 2020 Turbo Levo Comp. I took delivery 2 weeks ago - and have put about 300 miles on it since new.

Last week, I started getting a vibration (High pitched hum) from the front Brake disc. I did the following:

1. Removed the pads and sanded them to remove any contaminates.
2. Use 240 grit sand paper to rough up the surface of the disk.
3. Cleaned every thing and re-assembled and centered the the disk before tightening the caliper.

The vibration stopped for about 5 miles today - and then came back worse than ever. If I close the brake lever slightly, the sound stops. I appears that one of the pistons is not retracting completely. Also, with the pad removed, I need to squeeze the brake lever to get any one of the 4 pistons to advance.

I‘d take it to an LBS, but all of the shops are backed 3-4 weeks here in Chicago, so I’m going to have to fix this myself if I want to do any more riding before the snow flies.

My options appear to be:

1. Try bleeding the system
2. Rebuild the caliper
3. Replace the whole fucking assembly - handlebar assembly, caliper and disk.

Any thoughts would be appreciated.

 

[KennyB]

Replace the pads. Stock ones can be a pain. Loads of options on various threads, see below. I've got Uberbikes Race Matrix and like them, for what it's worth.

 

[iXi]

Have you tried getting a bit of brake fluid and rubbing it around the outside of the stuck piston and then pushing it back in with some pliers etc. Rinse repeat until it loosens up. Sometimes the rubber seals can get some build up and not work correctly.

 

[ManuelV]

Look at this clip (min 2:45) with more or less the same solution as suggested by iXi. The guy puts some oil around the pistons after having pulled them out 3 mm.

 

[paquo]

sometimes the pistons come out of balance, i have been able to correct it by carefully pushing that piston in without damaging the pad using a flat screwdriver , or

Get clean streak dry degreaser to keep brake components sterile
Get discobrakes sintered set of 4 for 30$ , sintered last longer /less maitenance. or kevlar for more braking power.
With old pads in place spray down brake to get rid dirt, then like dude in video use dot fluid dripped onto sides of piston(s) and then use a wide screw driver to hold one brake pad while applying the brake to get movement on the other 2 pistons then push them back in, repeat

 

[lumpy]

Have you tried getting a bit of brake fluid and rubbing it around the outside of the stuck piston and then pushing it back in with some pliers etc. Rinse repeat until it loosens up. Sometimes the rubber seals can get some build up and not work correctly.

This is what I've done in the past and it solved it for me. I used a Q-tip to apply it.
Just be sure to clean off the extra DOT form the caliper

 

[thewrx]

you should try reseting your piston placement, not sure I would add oil to the friction area of my calipers though.


basically just loosen the caliper, and move to one side then press lever, then move to other side and repeat, and repeat a few more times, then re-center caliper and tighten down.

If that doesn't work, re-surface your disk and replace your pads, if that doesn't work ditch the crappy sram brakes and get some magura's.

 

[Dirk74]

Be carefully with the flat screwdriver, better to use plastic, e.g. a tire lever.

I already posted this below in an other thread

Get the wheel and the pads out. Push the pistons back (use a plastic tire lever).
On a 4 pistons caliper block one pair with a small blead block (the SRAM pro bleeding kit includes a small one)

Gently! push the brake leaver and look if the pistons come out equally on both sides. Attention, do not push either one piston out of the caliper! Otherwise you would need to rebuild and bleed the caliper.

Clean the outside of the pistons with Isopropanol (use a cotton Q-tip) and then put a small droplet of brake fluid (DOT 5.1 for SRAM Brakes) on it, to reduce friction. Push them back (again use a plastic tire lever). Repeat pushing them out (gently) and back until they come out easily and equally.

Set the small blead block on the already service pistons and repeat the same with the other pair.

When done (with the 4 pistons all pushed back) clean everything carefully with Isopropanol to remove the brake fluid as it would ruin the pads (and other stuff).

Put the pads and the wheel back.

Readjust the alignment of the caliper with the rotor if necessary.

 

[Mikerb]

Be carefully with the flat screwdriver, better to use plastic, e.g. a tire lever.

I already posted this below in an other thread

Get the wheel and the pads out. Push the pistons back (use a plastic tire lever).
On a 4 pistons caliper block one pair with a small blead block (the SRAM pro bleeding kit includes a small one)

Gently! push the brake leaver and look if the pistons come out equally on both sides. Attention, do not push either one piston out of the caliper! Otherwise you would need to rebuild and bleed the caliper.

Clean the outside of the pistons with Isopropanol (use a cotton Q-tip) and then put a small droplet of brake fluid (DOT 5.1 for SRAM Brakes) on it, to reduce friction. Push them back (again use a plastic tire lever). Repeat pushing them out (gently) and back until they come out easily and equally.

Set the small blead block on the already service pistons and repeat the same with the other pair.

When done (with the 4 pistons all pushed back) clean everything carefully with Isopropanol to remove the brake fluid as it would ruin the pads (and other stuff).

Put the pads and the wheel back.

Readjust the alignment of the caliper with the rotor if necessary.

I agree totally with this method. Just to make sure you do not push a piston out of the caliper you can use a thin brake block roughly the same thickness as the disc plus pads between the pistons you want to clean and lube, whilst the other pair of pistons are blocked with a thick brake bleed block such that they remain flush with the caliper inner face.

 

[paquo]

i find it difficult to move the pistons without using the old pads because its like whack a mole

 

[2cool2fool]

The last time I posted this, I tried all of the suggestions and ended up buying a brand new RE lever, line and caliper. After installed it, it worked like new. Now, about only 600 miles later the piece of shit new calipher is doing exactly the same thing. I disassembled everything (at least this time, the pistons were all moving - just at different times) so they weren’t stuck in the caliper. Carefully cleaned, oiled (with brake fluid) and reassemble everything, bled the system - and FUCK - the pistons will not retract enough to eliminate contact with the disk after the first post-cleaning lever pull. I centered the caliper - but I’m still getting friction - that turns into near lock-up after a couple of miles. I bought the 2020 Comp last August brand new. It’s now been only 9 months with less than 1000 miles - and I had it with these horseshit SRAM brakes.

I don’t need MT7’s because most of my riding is trails without a lot of evaluation change. Any suggestions about what I can replace these shit RE brakes with? Thanks !

 

[Miru]

From what i remember guides suffer from sticky piston in the pump side(it’s made out of some shitty plastic that expands over time and the start to work poorly) so you might want to look into that too. Now to your question, 4 pot SLX’s seem to be the best bang for the buck.

 

[Mikerb]

The last time I posted this, I tried all of the suggestions and ended up buying a brand new RE lever, line and caliper. After installed it, it worked like new. Now, about only 600 miles later the piece of shit new calipher is doing exactly the same thing. I disassembled everything (at least this time, the pistons were all moving - just at different times) so they weren’t stuck in the caliper. Carefully cleaned, oiled (with brake fluid) and reassemble everything, bled the system - and FUCK - the pistons will not retract enough to eliminate contact with the disk after the first post-cleaning lever pull. I centered the caliper - but I’m still getting friction - that turns into near lock-up after a couple of miles. I bought the 2020 Comp last August brand new. It’s now been only 9 months with less than 1000 miles - and I had it with these horseshit SRAM brakes.

I don’t need MT7’s because most of my riding is trails without a lot of evaluation change. Any suggestions about what I can replace these shit RE brakes with? Thanks !

Release the bleed valve on the lever and press all 4 pistons on the caliper fully back.........you will lose a little fluid from the caliper so some paper towel is useful. Tighten the bleed valve back up. QED.

 

[2cool2fool]

Update: problem solved. Bought some Avid silicone brake grease (Amazon). First I removed the wheel and the pads. Then, I used a 4mm hex tool to simulate the disk and pumped all four pistons out until the hit the tool. Then, using a small artist brush, I applied the brake grease all the way around the expose part of each piston. I then forced each of the piston all the way back by twisting a large flathead screwdriver. After I cleaned everything off with isopropyl alcohol and reassembled. Problem solved.