Answered Shimano Zee - Caliper seal blown.

[routrax]

Hi Y'all,

I was bleeding my front brake, pushed the fluid through into the bleed cup and all seemed OK (bubbles stopped etc). After nipping up the bleed nipple and replacing the cap in the lever, the brake felt spongy. I pumped it a bit and then the lever lost all resistance and the caliper started dripping fluid

I've not bled many mtb brakes before, but have done cars and motorbikes loads, so pretty sure I did it right.

Does this look like a faulty caliper or possibly user error?

Cheers
Stephen

 

[Topov]

Hi Y'all,

I was bleeding my front brake, pushed the fluid through into the bleed cup and all seemed OK (bubbles stopped etc). After nipping up the bleed nipple and replacing the cap in the lever, the brake felt spongy. I pumped it a bit and then the lever lost all resistance and the caliper started dripping fluid

I've not bled many mtb brakes before, but have done cars and motorbikes loads, so pretty sure I did it right.

Does this look like a faulty caliper or possibly user error?

Cheers
Stephen

I hope you are not saying you took the full cap off the brake lever end, you only take the bleed screw out and attach the bowl then push the fluid from the bottom up, when fully bled I always put the bleed screw back in at the top and squeeze a little more at the bottom as tightening the nipple for a harder lever

 

[routrax]

I hope you are not saying you took the full cap off the brake lever end, you only take the bleed screw out and attach the bowl then push the fluid from the bottom up, when fully bled I always put the bleed screw back in at the top and squeeze a little more at the bottom as tightening the nipple for a harder lever

Nope, just the little allen bolt where the bleed cup/bowl screws in.

I've bled Shimano brakes a few times before successfully, was just canvassing opinion in the caliper leaking before whinge to CRC about the brand new Zee failing.

 

[Gary]

Warranty it.
you'll get a new caliper/full brake.

it's fairly common

 

[RickBullotta]

Hi Y'all,

I was bleeding my front brake, pushed the fluid through into the bleed cup and all seemed OK (bubbles stopped etc). After nipping up the bleed nipple and replacing the cap in the lever, the brake felt spongy. I pumped it a bit and then the lever lost all resistance and the caliper started dripping fluid

I've not bled many mtb brakes before, but have done cars and motorbikes loads, so pretty sure I did it right.

Does this look like a faulty caliper or possibly user error?

Cheers
Stephen

Did you forget to put a bleed block in? Common mistake.

 

[routrax]

Warranty it.
you'll get a new caliper/full brake.

it's fairly common

Did you forget to put a bleed block in? Common mistake.

Nope, bleed block in. The pistons were fully retracted.

 

[nepper]

Check if the piston is still at one piece. Common mistake is to put bleeding block in but not use the locking pin. Block tends to move around when sqeezing the lever and can crack the piston if no pin is used. It's ceramic piston that cracks easily. There is no spareparts for the caliper from Shimano, only replacement calipers.

Caliper has super simple structure. Two halves, four pistons and every piston has one rubber seal. Only causes for leak are seal damage or cracked piston.

 

[routrax]

Check if the piston is still at one piece. Common mistake is to put bleeding block in but not use the locking pin. Block tends to move around when sqeezing the lever and can crack the piston if no pin is used. It's ceramic piston that cracks easily. There is no spareparts for the caliper from Shimano, only replacement calipers.

Caliper has super simple structure. Two halves, four pistons and every piston has one rubber seal. Only causes for leak are seal damage or cracked piston.

Block was in OK. It's the seal.
I've managed to get a secondhand Saint caliper from a mechanic in a bike shop so I can at least get out whilst I'm in Spain.
Bit annoyed with myself for not researching the zee, as I'd would not have bought it looking at the reviews and problems. Also find it hard to believe the is no service kit.

I think I might have to rethink my brake provider as I like brakes to be reliable.

 

[nepper]

Feel free to look for a service kit from Shimano. No one has found it yet. Some Chinese company makes replacement pistons that have aluminum core. I asked for pistons / seals once from Shimano like many before me. They do not want customers / shops messing around their brakes.

 

[routrax]

Feel free to look for a service kit from Shimano. No one has found it yet. Some Chinese company makes replacement pistons that have aluminum core. I asked for pistons / seals once from Shimano like many before me. They do not want customers / shops messing around their brakes.

View attachment 23569

Hahaha, I'm not into research projects!
I like things to be repairable and don't really think brakes calipers should be disposable.

What are Sram like? can they be rebuilt or am I stuck with Hope. TBH I've always lusted after some Hope brakes, they do look quite sexy!

 

[Nasty Nick]

Hopes aren't as strong as zee's. All the new shimano stuff seems pretty good. All of my riding buddies are on magura, they are definitely strong and grabby. I've heard really really good things about the newer Hayes Dominions.

 

[dobbyhasfriends]

thought I had blown a seal once but it was just frost in my beard...

 

[steve_sordy]

I told my mate that I had spotted an albino Dalmation this morning. He said why did you do that? I replied that I had a felt tip pen with me and it seemed like the thing to do.