Hello,
I just got a set of the new Shimano M785 XT brakes.
I had to shorten the hoses and the brakes felt a bit ‘spongy’ after so I wanted to bleed them. Shimano say you need that yellow funnel tool but nobody in the world it seems has any in stock.

After a bit of research I tried using my Avid bleed kit which screws directly into the bleed port on the lever, and attached the other syringe to the bleed nipple at the caliper.

I have bled the brakes Avid-style, and have also followed Shimanos instructions accounting for the use of a syringe and not a funnel. I have gotten air out successfully it would seem and produced a real nice firm-feeling lever while the syringes are still attached.

As soon as I remove the syringes, oil erupts out of the bleed port with back-pressure, I replace the screw and try the lever.

No matter what I do I cant seem to get rid of what I can only describe as a ‘spongy’ feeling. There is definite resistance in the lever, however with some firm pressure I can pull them back to the bar front and rear.

I think the main issue is that I am just not used to Shimano brakes, having used battered Hope M4’s for the past 4-5 years and so do not really know what to expect. These feel similar to my rubbish Juicy 3’s on another bike, but not as firm as my GF’s old Deore brakes on her bike.

Incidentally, a car-park test pulling the brakes full on I can get it on the front wheel no problem, but with that softish feeling and a trip to Morzine at the end of this week I am a bit worried that something is still wrong that I don’t want showing up in the Alps.

So what sort of ‘feel’ is normal for Shimano brakes, should I be worried about being able to pull them to the bar(with not insignificant pressure) and also, any tips for a spot-on and firmer bleed using syringes?

Cheers.

Using an Avid bleed kit was potentially a big mistake. DOT fluid like in Avid brakes destroys the seals in mineral oil brake systems and there may well have been traces of DOT fluid in the Avid kit. Not a good idea at all really.

Shimano brakes should feel nice and solid, my 988 and 785s both do. I did use the proper yellow funnel thing though

Did my saints last week, open resovoir, attatch syringe to caliper bleed nipple,open nipple, push fluid through, close nipple, pull lever quickly a few times, top with fluid, close cap, remove syringe, clean with water, job done!My saints feel fantastic, not a hint of sponginess.

Shimano brakes normally feel rock solid to me, I reverse bleed with a syringe and a bit of tube.

Take the reservoir cover off, attach syringw to caliper bleed nipple and suck all the fluid out, then with fresh fluid refill thru the bleed nipple once the resevoir is full lock of the bleed nipple.

Replace cover and try, if they still feel a bit spongy hang the bike up by the front wheel and pull the levers back and lock off with zip ties and leave overnight.

That normally results in a rock solid feel for me.

The new XT do need the yellow cup tool to bleed them properly. With that and a syringe I have bled brakes very easily and achieved a very solid feel at the lever. If you ask your LBS to order 8UP 9803 from Madison this is the tool you need. SRP is £1.99

You need to close the bleed port before taking the syringe off. No need to screw it in, just use a bit of hose over the end of the nipple then you can close it. For the record, I have never managed to get either my 775 xts (self assembled) or slx (factory bled)brakes to feel anything other than a bit squishy, but still plenty powerful

Using an Avid bleed kit was potentially a big mistake. DOT fluid like in Avid brakes destroys the seals in mineral oil brake systems and there may well have been traces of DOT fluid in the Avid kit. Not a good idea at all really.

I know they use different fluid thanks, I washed the syringes very thoroughly first obviously.

Take the reservoir cover off,

The new/current XT’s and XTR’s(I presume) do not have a resevoir cap you can just lift off to reveal an open ‘bath’ resevoir like the older ones, there is a little metal plate under the chrome cover holding down the diaphragm, held in position by another screw. I don’t think you are supposed to be taking all of that out and I’m fairly certain you wouldn’t get a good bleed if you did.
Reading up on it, using the avid syringe without the plunger fitted (so long as its held vertical in some way) is equivalent to using the yellow plunger(which only Hong Kong seems to have in stock)that Shimano say you need.

refill thru the bleed nipple once the resevoir is full lock of the bleed nipple

I guess I’ll try this with the Avid syringe on the lever with the plunger removed, which should be the same thing. I have actually done it this way up to now but with the syringe at the top still having its plunger in. The lever has felt great, quick bite and very solid UNTIL I take the syringes off, then oil erupts out of the bleed screw-port and we’re back to sponginess again…. Ho Hum….

the yellow plunger(which only Hong Kong seems to have in stock)that Shimano say you need.

If you ask your LBS to order 8UP 9803 from Madison this is the tool you need. SRP is £1.99 and is in stock right now in the UK.

I know they use different fluid thanks, I washed the syringes very thoroughly first obviously

Not good enough – 0.5% is enough to bugger the seals. It may take a few weeks/months to take effect but it will get there.

Sorry to be the bearer of bad news but keep a very close eye on them. This happens occasionally in cars (I design car systems) and it’s invariably bad 😥